The copper surface

•

The copper surface is coated (or covered) with a layer of silver.

•

The tank is coated with an enamel paint.

•

The junction is plated with platinum.

•

All surfaces are silver plated.

neat, clean, very clean, nice.

* * *

► adjetivo

1 (transparente) clear, transparent

2 (claro) accurate, precise

3 (imagen) sharp

* * *

* * *

1) [imagen, fotografía] sharp, clear; [aire, agua] clear

2) [explicación, orden] clear; [conducta] irreproachable

* * *

- da adjetivo <foto/imagen> clear; < recuerdo> vivid; <cielo/agua> clear

* * *

= clean [cleaner -comp., cleanest -sup.], clear-cut, crisp [crisper -comp., crispest -sup.], neat [neater -comp., neatest -sup.], clean-cut, crystal-clear, licked, crystalline, uncloudy, unclouded, cut and dried [cut and dry].

Nota: Escrito con guiones cuando se usa como adjetivo.

Ex. Perhaps it is obvious that guiding must also be accurate, clean and tidy.

Ex. The hierarchical relationship is relatively clear-cut, and rather precise guideliness can be formulated to ensure that the BT/NT relationship is consistently applied.

Ex. A crisp, even impression became the norm, along with the use of respectable paper and ink.

Ex. What is possibly less easy is to making sure that the guiding stays clean, neat and accurate.

Ex. Librarians have a preference for nice, clean-cut, definable, easily-retrievable questions.

Ex. A crystal-clear mental picture of what the group should become is needed.

Ex. Modern art is often characterized by its overt acknowledgement of materials and process, whereas the licked surface of academic art is perceived as a sympton of pre-modern concerns.

Ex. Copper sulfate occurs as a blue crystalline powder prepared from copper oxide.

Ex. In that case, the peak of solar energy could be at an uncloudy moment in the morning or afternoon, even though the sun wasn't highest in the sky at that moment.

Ex. As they grow up in those heady post-war years, in the blue unclouded weather of the late 1940s, these are the sisters you'll never forget.

Ex. One of them snipped Ben Kline's life short, and Marla's determined to get to the root of a case that's anything but cut and dried.

----

* de un modo nítido = cleanly.

* poco nítido = untidy.

* * *

- da adjetivo <foto/imagen> clear; < recuerdo> vivid; <cielo/agua> clear

* * *

= clean [cleaner -comp., cleanest -sup.], clear-cut, crisp [crisper -comp., crispest -sup.], neat [neater -comp., neatest -sup.], clean-cut, crystal-clear, licked, crystalline, uncloudy, unclouded, cut and dried [cut and dry].

Nota: Escrito con guiones cuando se usa como adjetivo.

* * *

‹foto/imagen› clear, sharp, well-defined; ‹recuerdo› clear, vivid; ‹día/mañana› clear

dio una respuesta nítida y concisa she replied clearly and concisely

ojos de un azul nítido clear blue eyes

* * *

◊ -da adjetivo ‹foto/imagen› clear

* * *

nítido, -a adj

* * *

1 clear

2 imagen sharp

* * *

nítido, -da adj

claro: clear, vivid, sharp

 

(длительный) допустимый ток
Максимальное значение электрического тока, который может протекать длительно по проводнику, устройству или аппарату при определенных условиях без превышения определенного значения их температуры в установившемся режиме
[ ГОСТ Р МЭК 60050-826-2009]

Этот ток обозначают I_Z
[ ГОСТ Р 50571. 1-2009 ( МЭК 60364-1: 2005)]

EN

(continuous) current-carrying capacity
ampacity (US)
maximum value of electric current which can be carried continuously by a conductor, a device or an apparatus, under specified conditions without its steady-state temperature exceeding a specified value
[IEV number 826-11-13]

ampacity
The current in amperes that a conductor can carry continuously under the conditions of use without exceeding its temperature rating.
[National Electrical Cod]

FR

courant (permanent) admissible, m
valeur maximale du courant électrique qui peut parcourir en permanence, un conducteur, un dispositif ou un appareil, sans que sa température de régime permanent, dans des conditions données, soit supérieure à la valeur spécifiée
[IEV number 826-11-13]

Ampacity, the term is defined as the maximum amount of current a cable can carry before sustaining immediate or progressive deterioration. Also described as current rating or current-carrying capacity, is the RMS electric current which a device can continuously carry while remaining within its temperature rating. The ampacity of a cable depends on:

• its insulation temperature rating;
• conductor electrical properties for current;
• frequency, in the case of alternating currents;
• ability to dissipate heat, which depends on cable geometry and its surroundings;
• ambient temperature.

Electric wires have some resistance, and electric current flowing through them causes voltage drop and power dissipation, which heats the cable. Copper or aluminum can conduct a large amount of current before melting, but long before the conductors melt, their insulation would be damaged by the heat.

The ampacity for a power cable is thus based on physical and electrical properties of the material & construction of the conductor and of its insulation, ambient temperature, and environmental conditions adjacent to the cable. Having a large overall surface area may dissipate heat well if the environment can absorb the heat.

In a long run of cable, different conditions govern, and installation regulations normally specify that the most severe condition along the run governs the cable's rating. Cables run in wet or oily locations may carry a lower temperature rating than in a dry installation. Derating is necessary for multiple circuits in close proximity. When multiple cables are near, each contributes heat to the others and diminishes the amount of cooling air that can flow past the individual cables. The overall ampacity of the insulated conductors in a bundle of more than 3 must be derated, whether in a raceway or cable. Usually the de-rating factor is tabulated in a nation's wiring regulations.

Depending on the type of insulating material, common maximum allowable temperatures at the surface of the conductor are 60, 75 and 90 degrees Celsius, often with an ambient air temperature of 30°C. In the U.S., 105°C is allowed with ambient of 40°C, for larger power cables, especially those operating at more than 2 kV. Likewise, specific insulations are rated 150, 200 or 250°C.

The allowed current in cables generally needs to be decreased (derated) when the cable is covered with fireproofing material.

For example, the United States National Electric Code, Table 310-16, specifies that up to three 8 AWG copper wires having a common insulating material (THWN) in a raceway, cable, or direct burial has an ampacity of 50 A when the ambient air is 30°C, the conductor surface temperature allowed to be 75°C. A single insulated conductor in air has 70 A rating.

Ampacity rating is normally for continuous current, and short periods of overcurrent occur without harm in most cabling systems. The acceptable magnitude and duration of overcurrent is a more complex topic than ampacity.

When designing an electrical system, one will normally need to know the current rating for the following:

• Wires
• Printed Circuit Board traces, where included
• Fuses
• Circuit breakers
• All or nearly all components used

Some devices are limited by power rating, and when this power rating occurs below their current limit, it is not necessary to know the current limit to design a system. A common example of this is lightbulb holders.

[http://en.wikipedia.org/wiki/Ampacity]

Тематики

• электротехника, основные понятия

Синонимы

• длительно допустимый ток
• допустимый ток

EN

• ampacity (US)
• continuous current
• continuous current-carrying capacity
• current-carrying capacity

DE

• Dauerstrombelastbarkeit, f
• Strombelastbarkeit, f

FR

• courant admissible, m
• courant permanent admissible, m

 

(длительный) допустимый ток
Максимальное значение электрического тока, который может протекать длительно по проводнику, устройству или аппарату при определенных условиях без превышения определенного значения их температуры в установившемся режиме
[ ГОСТ Р МЭК 60050-826-2009]

Этот ток обозначают I_Z
[ ГОСТ Р 50571. 1-2009 ( МЭК 60364-1: 2005)]

EN

(continuous) current-carrying capacity
ampacity (US)
maximum value of electric current which can be carried continuously by a conductor, a device or an apparatus, under specified conditions without its steady-state temperature exceeding a specified value
[IEV number 826-11-13]

ampacity
The current in amperes that a conductor can carry continuously under the conditions of use without exceeding its temperature rating.
[National Electrical Cod]

FR

courant (permanent) admissible, m
valeur maximale du courant électrique qui peut parcourir en permanence, un conducteur, un dispositif ou un appareil, sans que sa température de régime permanent, dans des conditions données, soit supérieure à la valeur spécifiée
[IEV number 826-11-13]

Ampacity, the term is defined as the maximum amount of current a cable can carry before sustaining immediate or progressive deterioration. Also described as current rating or current-carrying capacity, is the RMS electric current which a device can continuously carry while remaining within its temperature rating. The ampacity of a cable depends on:

• its insulation temperature rating;
• conductor electrical properties for current;
• frequency, in the case of alternating currents;
• ability to dissipate heat, which depends on cable geometry and its surroundings;
• ambient temperature.

Electric wires have some resistance, and electric current flowing through them causes voltage drop and power dissipation, which heats the cable. Copper or aluminum can conduct a large amount of current before melting, but long before the conductors melt, their insulation would be damaged by the heat.

The ampacity for a power cable is thus based on physical and electrical properties of the material & construction of the conductor and of its insulation, ambient temperature, and environmental conditions adjacent to the cable. Having a large overall surface area may dissipate heat well if the environment can absorb the heat.

In a long run of cable, different conditions govern, and installation regulations normally specify that the most severe condition along the run governs the cable's rating. Cables run in wet or oily locations may carry a lower temperature rating than in a dry installation. Derating is necessary for multiple circuits in close proximity. When multiple cables are near, each contributes heat to the others and diminishes the amount of cooling air that can flow past the individual cables. The overall ampacity of the insulated conductors in a bundle of more than 3 must be derated, whether in a raceway or cable. Usually the de-rating factor is tabulated in a nation's wiring regulations.

Depending on the type of insulating material, common maximum allowable temperatures at the surface of the conductor are 60, 75 and 90 degrees Celsius, often with an ambient air temperature of 30°C. In the U.S., 105°C is allowed with ambient of 40°C, for larger power cables, especially those operating at more than 2 kV. Likewise, specific insulations are rated 150, 200 or 250°C.

The allowed current in cables generally needs to be decreased (derated) when the cable is covered with fireproofing material.

For example, the United States National Electric Code, Table 310-16, specifies that up to three 8 AWG copper wires having a common insulating material (THWN) in a raceway, cable, or direct burial has an ampacity of 50 A when the ambient air is 30°C, the conductor surface temperature allowed to be 75°C. A single insulated conductor in air has 70 A rating.

Ampacity rating is normally for continuous current, and short periods of overcurrent occur without harm in most cabling systems. The acceptable magnitude and duration of overcurrent is a more complex topic than ampacity.

When designing an electrical system, one will normally need to know the current rating for the following:

• Wires
• Printed Circuit Board traces, where included
• Fuses
• Circuit breakers
• All or nearly all components used

Some devices are limited by power rating, and when this power rating occurs below their current limit, it is not necessary to know the current limit to design a system. A common example of this is lightbulb holders.

[http://en.wikipedia.org/wiki/Ampacity]

Тематики

• электротехника, основные понятия

Синонимы

• длительно допустимый ток
• допустимый ток

EN

• ampacity (US)
• continuous current
• continuous current-carrying capacity
• current-carrying capacity

DE

• Dauerstrombelastbarkeit, f
• Strombelastbarkeit, f

FR

• courant admissible, m
• courant permanent admissible, m

 

(длительный) допустимый ток
Максимальное значение электрического тока, который может протекать длительно по проводнику, устройству или аппарату при определенных условиях без превышения определенного значения их температуры в установившемся режиме
[ ГОСТ Р МЭК 60050-826-2009]

Этот ток обозначают I_Z
[ ГОСТ Р 50571. 1-2009 ( МЭК 60364-1: 2005)]

EN

(continuous) current-carrying capacity
ampacity (US)
maximum value of electric current which can be carried continuously by a conductor, a device or an apparatus, under specified conditions without its steady-state temperature exceeding a specified value
[IEV number 826-11-13]

ampacity
The current in amperes that a conductor can carry continuously under the conditions of use without exceeding its temperature rating.
[National Electrical Cod]

FR

courant (permanent) admissible, m
valeur maximale du courant électrique qui peut parcourir en permanence, un conducteur, un dispositif ou un appareil, sans que sa température de régime permanent, dans des conditions données, soit supérieure à la valeur spécifiée
[IEV number 826-11-13]

Ampacity, the term is defined as the maximum amount of current a cable can carry before sustaining immediate or progressive deterioration. Also described as current rating or current-carrying capacity, is the RMS electric current which a device can continuously carry while remaining within its temperature rating. The ampacity of a cable depends on:

• its insulation temperature rating;
• conductor electrical properties for current;
• frequency, in the case of alternating currents;
• ability to dissipate heat, which depends on cable geometry and its surroundings;
• ambient temperature.

Electric wires have some resistance, and electric current flowing through them causes voltage drop and power dissipation, which heats the cable. Copper or aluminum can conduct a large amount of current before melting, but long before the conductors melt, their insulation would be damaged by the heat.

The ampacity for a power cable is thus based on physical and electrical properties of the material & construction of the conductor and of its insulation, ambient temperature, and environmental conditions adjacent to the cable. Having a large overall surface area may dissipate heat well if the environment can absorb the heat.

In a long run of cable, different conditions govern, and installation regulations normally specify that the most severe condition along the run governs the cable's rating. Cables run in wet or oily locations may carry a lower temperature rating than in a dry installation. Derating is necessary for multiple circuits in close proximity. When multiple cables are near, each contributes heat to the others and diminishes the amount of cooling air that can flow past the individual cables. The overall ampacity of the insulated conductors in a bundle of more than 3 must be derated, whether in a raceway or cable. Usually the de-rating factor is tabulated in a nation's wiring regulations.

Depending on the type of insulating material, common maximum allowable temperatures at the surface of the conductor are 60, 75 and 90 degrees Celsius, often with an ambient air temperature of 30°C. In the U.S., 105°C is allowed with ambient of 40°C, for larger power cables, especially those operating at more than 2 kV. Likewise, specific insulations are rated 150, 200 or 250°C.

The allowed current in cables generally needs to be decreased (derated) when the cable is covered with fireproofing material.

For example, the United States National Electric Code, Table 310-16, specifies that up to three 8 AWG copper wires having a common insulating material (THWN) in a raceway, cable, or direct burial has an ampacity of 50 A when the ambient air is 30°C, the conductor surface temperature allowed to be 75°C. A single insulated conductor in air has 70 A rating.

Ampacity rating is normally for continuous current, and short periods of overcurrent occur without harm in most cabling systems. The acceptable magnitude and duration of overcurrent is a more complex topic than ampacity.

When designing an electrical system, one will normally need to know the current rating for the following:

• Wires
• Printed Circuit Board traces, where included
• Fuses
• Circuit breakers
• All or nearly all components used

Some devices are limited by power rating, and when this power rating occurs below their current limit, it is not necessary to know the current limit to design a system. A common example of this is lightbulb holders.

[http://en.wikipedia.org/wiki/Ampacity]

Тематики

• электротехника, основные понятия

Синонимы

• длительно допустимый ток
• допустимый ток

EN

• ampacity (US)
• continuous current
• continuous current-carrying capacity
• current-carrying capacity

DE

• Dauerstrombelastbarkeit, f
• Strombelastbarkeit, f

FR

• courant admissible, m
• courant permanent admissible, m

 

(длительный) допустимый ток
Максимальное значение электрического тока, который может протекать длительно по проводнику, устройству или аппарату при определенных условиях без превышения определенного значения их температуры в установившемся режиме
[ ГОСТ Р МЭК 60050-826-2009]

Этот ток обозначают I_Z
[ ГОСТ Р 50571. 1-2009 ( МЭК 60364-1: 2005)]

EN

(continuous) current-carrying capacity
ampacity (US)
maximum value of electric current which can be carried continuously by a conductor, a device or an apparatus, under specified conditions without its steady-state temperature exceeding a specified value
[IEV number 826-11-13]

ampacity
The current in amperes that a conductor can carry continuously under the conditions of use without exceeding its temperature rating.
[National Electrical Cod]

FR

courant (permanent) admissible, m
valeur maximale du courant électrique qui peut parcourir en permanence, un conducteur, un dispositif ou un appareil, sans que sa température de régime permanent, dans des conditions données, soit supérieure à la valeur spécifiée
[IEV number 826-11-13]

Ampacity, the term is defined as the maximum amount of current a cable can carry before sustaining immediate or progressive deterioration. Also described as current rating or current-carrying capacity, is the RMS electric current which a device can continuously carry while remaining within its temperature rating. The ampacity of a cable depends on:

• its insulation temperature rating;
• conductor electrical properties for current;
• frequency, in the case of alternating currents;
• ability to dissipate heat, which depends on cable geometry and its surroundings;
• ambient temperature.

Electric wires have some resistance, and electric current flowing through them causes voltage drop and power dissipation, which heats the cable. Copper or aluminum can conduct a large amount of current before melting, but long before the conductors melt, their insulation would be damaged by the heat.

The ampacity for a power cable is thus based on physical and electrical properties of the material & construction of the conductor and of its insulation, ambient temperature, and environmental conditions adjacent to the cable. Having a large overall surface area may dissipate heat well if the environment can absorb the heat.

In a long run of cable, different conditions govern, and installation regulations normally specify that the most severe condition along the run governs the cable's rating. Cables run in wet or oily locations may carry a lower temperature rating than in a dry installation. Derating is necessary for multiple circuits in close proximity. When multiple cables are near, each contributes heat to the others and diminishes the amount of cooling air that can flow past the individual cables. The overall ampacity of the insulated conductors in a bundle of more than 3 must be derated, whether in a raceway or cable. Usually the de-rating factor is tabulated in a nation's wiring regulations.

Depending on the type of insulating material, common maximum allowable temperatures at the surface of the conductor are 60, 75 and 90 degrees Celsius, often with an ambient air temperature of 30°C. In the U.S., 105°C is allowed with ambient of 40°C, for larger power cables, especially those operating at more than 2 kV. Likewise, specific insulations are rated 150, 200 or 250°C.

The allowed current in cables generally needs to be decreased (derated) when the cable is covered with fireproofing material.

For example, the United States National Electric Code, Table 310-16, specifies that up to three 8 AWG copper wires having a common insulating material (THWN) in a raceway, cable, or direct burial has an ampacity of 50 A when the ambient air is 30°C, the conductor surface temperature allowed to be 75°C. A single insulated conductor in air has 70 A rating.

Ampacity rating is normally for continuous current, and short periods of overcurrent occur without harm in most cabling systems. The acceptable magnitude and duration of overcurrent is a more complex topic than ampacity.

When designing an electrical system, one will normally need to know the current rating for the following:

• Wires
• Printed Circuit Board traces, where included
• Fuses
• Circuit breakers
• All or nearly all components used

Some devices are limited by power rating, and when this power rating occurs below their current limit, it is not necessary to know the current limit to design a system. A common example of this is lightbulb holders.

[http://en.wikipedia.org/wiki/Ampacity]

Тематики

• электротехника, основные понятия

Синонимы

• длительно допустимый ток
• допустимый ток

EN

• ampacity (US)
• continuous current
• continuous current-carrying capacity
• current-carrying capacity

DE

• Dauerstrombelastbarkeit, f
• Strombelastbarkeit, f

FR

• courant admissible, m
• courant permanent admissible, m

 

(длительный) допустимый ток
Максимальное значение электрического тока, который может протекать длительно по проводнику, устройству или аппарату при определенных условиях без превышения определенного значения их температуры в установившемся режиме
[ ГОСТ Р МЭК 60050-826-2009]

Этот ток обозначают I_Z
[ ГОСТ Р 50571. 1-2009 ( МЭК 60364-1: 2005)]

EN

(continuous) current-carrying capacity
ampacity (US)
maximum value of electric current which can be carried continuously by a conductor, a device or an apparatus, under specified conditions without its steady-state temperature exceeding a specified value
[IEV number 826-11-13]

ampacity
The current in amperes that a conductor can carry continuously under the conditions of use without exceeding its temperature rating.
[National Electrical Cod]

FR

courant (permanent) admissible, m
valeur maximale du courant électrique qui peut parcourir en permanence, un conducteur, un dispositif ou un appareil, sans que sa température de régime permanent, dans des conditions données, soit supérieure à la valeur spécifiée
[IEV number 826-11-13]

Ampacity, the term is defined as the maximum amount of current a cable can carry before sustaining immediate or progressive deterioration. Also described as current rating or current-carrying capacity, is the RMS electric current which a device can continuously carry while remaining within its temperature rating. The ampacity of a cable depends on:

• its insulation temperature rating;
• conductor electrical properties for current;
• frequency, in the case of alternating currents;
• ability to dissipate heat, which depends on cable geometry and its surroundings;
• ambient temperature.

Electric wires have some resistance, and electric current flowing through them causes voltage drop and power dissipation, which heats the cable. Copper or aluminum can conduct a large amount of current before melting, but long before the conductors melt, their insulation would be damaged by the heat.

The ampacity for a power cable is thus based on physical and electrical properties of the material & construction of the conductor and of its insulation, ambient temperature, and environmental conditions adjacent to the cable. Having a large overall surface area may dissipate heat well if the environment can absorb the heat.

In a long run of cable, different conditions govern, and installation regulations normally specify that the most severe condition along the run governs the cable's rating. Cables run in wet or oily locations may carry a lower temperature rating than in a dry installation. Derating is necessary for multiple circuits in close proximity. When multiple cables are near, each contributes heat to the others and diminishes the amount of cooling air that can flow past the individual cables. The overall ampacity of the insulated conductors in a bundle of more than 3 must be derated, whether in a raceway or cable. Usually the de-rating factor is tabulated in a nation's wiring regulations.

Depending on the type of insulating material, common maximum allowable temperatures at the surface of the conductor are 60, 75 and 90 degrees Celsius, often with an ambient air temperature of 30°C. In the U.S., 105°C is allowed with ambient of 40°C, for larger power cables, especially those operating at more than 2 kV. Likewise, specific insulations are rated 150, 200 or 250°C.

The allowed current in cables generally needs to be decreased (derated) when the cable is covered with fireproofing material.

For example, the United States National Electric Code, Table 310-16, specifies that up to three 8 AWG copper wires having a common insulating material (THWN) in a raceway, cable, or direct burial has an ampacity of 50 A when the ambient air is 30°C, the conductor surface temperature allowed to be 75°C. A single insulated conductor in air has 70 A rating.

Ampacity rating is normally for continuous current, and short periods of overcurrent occur without harm in most cabling systems. The acceptable magnitude and duration of overcurrent is a more complex topic than ampacity.

When designing an electrical system, one will normally need to know the current rating for the following:

• Wires
• Printed Circuit Board traces, where included
• Fuses
• Circuit breakers
• All or nearly all components used

Some devices are limited by power rating, and when this power rating occurs below their current limit, it is not necessary to know the current limit to design a system. A common example of this is lightbulb holders.

[http://en.wikipedia.org/wiki/Ampacity]

Тематики

• электротехника, основные понятия

Синонимы

• длительно допустимый ток
• допустимый ток

EN

• ampacity (US)
• continuous current
• continuous current-carrying capacity
• current-carrying capacity

DE

• Dauerstrombelastbarkeit, f
• Strombelastbarkeit, f

FR

• courant admissible, m
• courant permanent admissible, m

 

(длительный) допустимый ток
Максимальное значение электрического тока, который может протекать длительно по проводнику, устройству или аппарату при определенных условиях без превышения определенного значения их температуры в установившемся режиме
[ ГОСТ Р МЭК 60050-826-2009]

Этот ток обозначают I_Z
[ ГОСТ Р 50571. 1-2009 ( МЭК 60364-1: 2005)]

EN

(continuous) current-carrying capacity
ampacity (US)
maximum value of electric current which can be carried continuously by a conductor, a device or an apparatus, under specified conditions without its steady-state temperature exceeding a specified value
[IEV number 826-11-13]

ampacity
The current in amperes that a conductor can carry continuously under the conditions of use without exceeding its temperature rating.
[National Electrical Cod]

FR

courant (permanent) admissible, m
valeur maximale du courant électrique qui peut parcourir en permanence, un conducteur, un dispositif ou un appareil, sans que sa température de régime permanent, dans des conditions données, soit supérieure à la valeur spécifiée
[IEV number 826-11-13]

Ampacity, the term is defined as the maximum amount of current a cable can carry before sustaining immediate or progressive deterioration. Also described as current rating or current-carrying capacity, is the RMS electric current which a device can continuously carry while remaining within its temperature rating. The ampacity of a cable depends on:

• its insulation temperature rating;
• conductor electrical properties for current;
• frequency, in the case of alternating currents;
• ability to dissipate heat, which depends on cable geometry and its surroundings;
• ambient temperature.

Electric wires have some resistance, and electric current flowing through them causes voltage drop and power dissipation, which heats the cable. Copper or aluminum can conduct a large amount of current before melting, but long before the conductors melt, their insulation would be damaged by the heat.

The ampacity for a power cable is thus based on physical and electrical properties of the material & construction of the conductor and of its insulation, ambient temperature, and environmental conditions adjacent to the cable. Having a large overall surface area may dissipate heat well if the environment can absorb the heat.

In a long run of cable, different conditions govern, and installation regulations normally specify that the most severe condition along the run governs the cable's rating. Cables run in wet or oily locations may carry a lower temperature rating than in a dry installation. Derating is necessary for multiple circuits in close proximity. When multiple cables are near, each contributes heat to the others and diminishes the amount of cooling air that can flow past the individual cables. The overall ampacity of the insulated conductors in a bundle of more than 3 must be derated, whether in a raceway or cable. Usually the de-rating factor is tabulated in a nation's wiring regulations.

Depending on the type of insulating material, common maximum allowable temperatures at the surface of the conductor are 60, 75 and 90 degrees Celsius, often with an ambient air temperature of 30°C. In the U.S., 105°C is allowed with ambient of 40°C, for larger power cables, especially those operating at more than 2 kV. Likewise, specific insulations are rated 150, 200 or 250°C.

The allowed current in cables generally needs to be decreased (derated) when the cable is covered with fireproofing material.

For example, the United States National Electric Code, Table 310-16, specifies that up to three 8 AWG copper wires having a common insulating material (THWN) in a raceway, cable, or direct burial has an ampacity of 50 A when the ambient air is 30°C, the conductor surface temperature allowed to be 75°C. A single insulated conductor in air has 70 A rating.

Ampacity rating is normally for continuous current, and short periods of overcurrent occur without harm in most cabling systems. The acceptable magnitude and duration of overcurrent is a more complex topic than ampacity.

When designing an electrical system, one will normally need to know the current rating for the following:

• Wires
• Printed Circuit Board traces, where included
• Fuses
• Circuit breakers
• All or nearly all components used

Some devices are limited by power rating, and when this power rating occurs below their current limit, it is not necessary to know the current limit to design a system. A common example of this is lightbulb holders.

[http://en.wikipedia.org/wiki/Ampacity]

Тематики

• электротехника, основные понятия

Синонимы

• длительно допустимый ток
• допустимый ток

EN

• ampacity (US)
• continuous current
• continuous current-carrying capacity
• current-carrying capacity

DE

• Dauerstrombelastbarkeit, f
• Strombelastbarkeit, f

FR

• courant admissible, m
• courant permanent admissible, m

 

(длительный) допустимый ток
Максимальное значение электрического тока, который может протекать длительно по проводнику, устройству или аппарату при определенных условиях без превышения определенного значения их температуры в установившемся режиме
[ ГОСТ Р МЭК 60050-826-2009]

Этот ток обозначают I_Z
[ ГОСТ Р 50571. 1-2009 ( МЭК 60364-1: 2005)]

EN

(continuous) current-carrying capacity
ampacity (US)
maximum value of electric current which can be carried continuously by a conductor, a device or an apparatus, under specified conditions without its steady-state temperature exceeding a specified value
[IEV number 826-11-13]

ampacity
The current in amperes that a conductor can carry continuously under the conditions of use without exceeding its temperature rating.
[National Electrical Cod]

FR

courant (permanent) admissible, m
valeur maximale du courant électrique qui peut parcourir en permanence, un conducteur, un dispositif ou un appareil, sans que sa température de régime permanent, dans des conditions données, soit supérieure à la valeur spécifiée
[IEV number 826-11-13]

Ampacity, the term is defined as the maximum amount of current a cable can carry before sustaining immediate or progressive deterioration. Also described as current rating or current-carrying capacity, is the RMS electric current which a device can continuously carry while remaining within its temperature rating. The ampacity of a cable depends on:

• its insulation temperature rating;
• conductor electrical properties for current;
• frequency, in the case of alternating currents;
• ability to dissipate heat, which depends on cable geometry and its surroundings;
• ambient temperature.

Electric wires have some resistance, and electric current flowing through them causes voltage drop and power dissipation, which heats the cable. Copper or aluminum can conduct a large amount of current before melting, but long before the conductors melt, their insulation would be damaged by the heat.

The ampacity for a power cable is thus based on physical and electrical properties of the material & construction of the conductor and of its insulation, ambient temperature, and environmental conditions adjacent to the cable. Having a large overall surface area may dissipate heat well if the environment can absorb the heat.

In a long run of cable, different conditions govern, and installation regulations normally specify that the most severe condition along the run governs the cable's rating. Cables run in wet or oily locations may carry a lower temperature rating than in a dry installation. Derating is necessary for multiple circuits in close proximity. When multiple cables are near, each contributes heat to the others and diminishes the amount of cooling air that can flow past the individual cables. The overall ampacity of the insulated conductors in a bundle of more than 3 must be derated, whether in a raceway or cable. Usually the de-rating factor is tabulated in a nation's wiring regulations.

Depending on the type of insulating material, common maximum allowable temperatures at the surface of the conductor are 60, 75 and 90 degrees Celsius, often with an ambient air temperature of 30°C. In the U.S., 105°C is allowed with ambient of 40°C, for larger power cables, especially those operating at more than 2 kV. Likewise, specific insulations are rated 150, 200 or 250°C.

The allowed current in cables generally needs to be decreased (derated) when the cable is covered with fireproofing material.

For example, the United States National Electric Code, Table 310-16, specifies that up to three 8 AWG copper wires having a common insulating material (THWN) in a raceway, cable, or direct burial has an ampacity of 50 A when the ambient air is 30°C, the conductor surface temperature allowed to be 75°C. A single insulated conductor in air has 70 A rating.

Ampacity rating is normally for continuous current, and short periods of overcurrent occur without harm in most cabling systems. The acceptable magnitude and duration of overcurrent is a more complex topic than ampacity.

When designing an electrical system, one will normally need to know the current rating for the following:

• Wires
• Printed Circuit Board traces, where included
• Fuses
• Circuit breakers
• All or nearly all components used

Some devices are limited by power rating, and when this power rating occurs below their current limit, it is not necessary to know the current limit to design a system. A common example of this is lightbulb holders.

[http://en.wikipedia.org/wiki/Ampacity]

Тематики

• электротехника, основные понятия

Синонимы

• длительно допустимый ток
• допустимый ток

EN

• ampacity (US)
• continuous current
• continuous current-carrying capacity
• current-carrying capacity

DE

• Dauerstrombelastbarkeit, f
• Strombelastbarkeit, f

FR

• courant admissible, m
• courant permanent admissible, m

 

длительная пропускная способность по току
—
[Я.Н.Лугинский, М.С.Фези-Жилинская, Ю.С.Кабиров. Англо-русский словарь по электротехнике и электроэнергетике, Москва, 1999 г.]

Тематики

• электротехника, основные понятия

EN

• continuous current-carrying capacity

 

(длительный) допустимый ток
Максимальное значение электрического тока, который может протекать длительно по проводнику, устройству или аппарату при определенных условиях без превышения определенного значения их температуры в установившемся режиме
[ ГОСТ Р МЭК 60050-826-2009]

Этот ток обозначают I_Z
[ ГОСТ Р 50571. 1-2009 ( МЭК 60364-1: 2005)]

EN

(continuous) current-carrying capacity
ampacity (US)
maximum value of electric current which can be carried continuously by a conductor, a device or an apparatus, under specified conditions without its steady-state temperature exceeding a specified value
[IEV number 826-11-13]

ampacity
The current in amperes that a conductor can carry continuously under the conditions of use without exceeding its temperature rating.
[National Electrical Cod]

FR

courant (permanent) admissible, m
valeur maximale du courant électrique qui peut parcourir en permanence, un conducteur, un dispositif ou un appareil, sans que sa température de régime permanent, dans des conditions données, soit supérieure à la valeur spécifiée
[IEV number 826-11-13]

Ampacity, the term is defined as the maximum amount of current a cable can carry before sustaining immediate or progressive deterioration. Also described as current rating or current-carrying capacity, is the RMS electric current which a device can continuously carry while remaining within its temperature rating. The ampacity of a cable depends on:

• its insulation temperature rating;
• conductor electrical properties for current;
• frequency, in the case of alternating currents;
• ability to dissipate heat, which depends on cable geometry and its surroundings;
• ambient temperature.

Electric wires have some resistance, and electric current flowing through them causes voltage drop and power dissipation, which heats the cable. Copper or aluminum can conduct a large amount of current before melting, but long before the conductors melt, their insulation would be damaged by the heat.

The ampacity for a power cable is thus based on physical and electrical properties of the material & construction of the conductor and of its insulation, ambient temperature, and environmental conditions adjacent to the cable. Having a large overall surface area may dissipate heat well if the environment can absorb the heat.

In a long run of cable, different conditions govern, and installation regulations normally specify that the most severe condition along the run governs the cable's rating. Cables run in wet or oily locations may carry a lower temperature rating than in a dry installation. Derating is necessary for multiple circuits in close proximity. When multiple cables are near, each contributes heat to the others and diminishes the amount of cooling air that can flow past the individual cables. The overall ampacity of the insulated conductors in a bundle of more than 3 must be derated, whether in a raceway or cable. Usually the de-rating factor is tabulated in a nation's wiring regulations.

Depending on the type of insulating material, common maximum allowable temperatures at the surface of the conductor are 60, 75 and 90 degrees Celsius, often with an ambient air temperature of 30°C. In the U.S., 105°C is allowed with ambient of 40°C, for larger power cables, especially those operating at more than 2 kV. Likewise, specific insulations are rated 150, 200 or 250°C.

The allowed current in cables generally needs to be decreased (derated) when the cable is covered with fireproofing material.

For example, the United States National Electric Code, Table 310-16, specifies that up to three 8 AWG copper wires having a common insulating material (THWN) in a raceway, cable, or direct burial has an ampacity of 50 A when the ambient air is 30°C, the conductor surface temperature allowed to be 75°C. A single insulated conductor in air has 70 A rating.

Ampacity rating is normally for continuous current, and short periods of overcurrent occur without harm in most cabling systems. The acceptable magnitude and duration of overcurrent is a more complex topic than ampacity.

When designing an electrical system, one will normally need to know the current rating for the following:

• Wires
• Printed Circuit Board traces, where included
• Fuses
• Circuit breakers
• All or nearly all components used

Some devices are limited by power rating, and when this power rating occurs below their current limit, it is not necessary to know the current limit to design a system. A common example of this is lightbulb holders.

[http://en.wikipedia.org/wiki/Ampacity]

Тематики

• электротехника, основные понятия

Синонимы

• длительно допустимый ток
• допустимый ток

EN

• ampacity (US)
• continuous current
• continuous current-carrying capacity
• current-carrying capacity

DE

• Dauerstrombelastbarkeit, f
• Strombelastbarkeit, f

FR

• courant admissible, m
• courant permanent admissible, m

 

(длительный) допустимый ток
Максимальное значение электрического тока, который может протекать длительно по проводнику, устройству или аппарату при определенных условиях без превышения определенного значения их температуры в установившемся режиме
[ ГОСТ Р МЭК 60050-826-2009]

Этот ток обозначают I_Z
[ ГОСТ Р 50571. 1-2009 ( МЭК 60364-1: 2005)]

EN

(continuous) current-carrying capacity
ampacity (US)
maximum value of electric current which can be carried continuously by a conductor, a device or an apparatus, under specified conditions without its steady-state temperature exceeding a specified value
[IEV number 826-11-13]

ampacity
The current in amperes that a conductor can carry continuously under the conditions of use without exceeding its temperature rating.
[National Electrical Cod]

FR

courant (permanent) admissible, m
valeur maximale du courant électrique qui peut parcourir en permanence, un conducteur, un dispositif ou un appareil, sans que sa température de régime permanent, dans des conditions données, soit supérieure à la valeur spécifiée
[IEV number 826-11-13]

Ampacity, the term is defined as the maximum amount of current a cable can carry before sustaining immediate or progressive deterioration. Also described as current rating or current-carrying capacity, is the RMS electric current which a device can continuously carry while remaining within its temperature rating. The ampacity of a cable depends on:

• its insulation temperature rating;
• conductor electrical properties for current;
• frequency, in the case of alternating currents;
• ability to dissipate heat, which depends on cable geometry and its surroundings;
• ambient temperature.

Electric wires have some resistance, and electric current flowing through them causes voltage drop and power dissipation, which heats the cable. Copper or aluminum can conduct a large amount of current before melting, but long before the conductors melt, their insulation would be damaged by the heat.

The ampacity for a power cable is thus based on physical and electrical properties of the material & construction of the conductor and of its insulation, ambient temperature, and environmental conditions adjacent to the cable. Having a large overall surface area may dissipate heat well if the environment can absorb the heat.

In a long run of cable, different conditions govern, and installation regulations normally specify that the most severe condition along the run governs the cable's rating. Cables run in wet or oily locations may carry a lower temperature rating than in a dry installation. Derating is necessary for multiple circuits in close proximity. When multiple cables are near, each contributes heat to the others and diminishes the amount of cooling air that can flow past the individual cables. The overall ampacity of the insulated conductors in a bundle of more than 3 must be derated, whether in a raceway or cable. Usually the de-rating factor is tabulated in a nation's wiring regulations.

Depending on the type of insulating material, common maximum allowable temperatures at the surface of the conductor are 60, 75 and 90 degrees Celsius, often with an ambient air temperature of 30°C. In the U.S., 105°C is allowed with ambient of 40°C, for larger power cables, especially those operating at more than 2 kV. Likewise, specific insulations are rated 150, 200 or 250°C.

The allowed current in cables generally needs to be decreased (derated) when the cable is covered with fireproofing material.

For example, the United States National Electric Code, Table 310-16, specifies that up to three 8 AWG copper wires having a common insulating material (THWN) in a raceway, cable, or direct burial has an ampacity of 50 A when the ambient air is 30°C, the conductor surface temperature allowed to be 75°C. A single insulated conductor in air has 70 A rating.

Ampacity rating is normally for continuous current, and short periods of overcurrent occur without harm in most cabling systems. The acceptable magnitude and duration of overcurrent is a more complex topic than ampacity.

When designing an electrical system, one will normally need to know the current rating for the following:

• Wires
• Printed Circuit Board traces, where included
• Fuses
• Circuit breakers
• All or nearly all components used

Some devices are limited by power rating, and when this power rating occurs below their current limit, it is not necessary to know the current limit to design a system. A common example of this is lightbulb holders.

[http://en.wikipedia.org/wiki/Ampacity]

Тематики

• электротехника, основные понятия

Синонимы

• длительно допустимый ток
• допустимый ток

EN

• ampacity (US)
• continuous current
• continuous current-carrying capacity
• current-carrying capacity

DE

• Dauerstrombelastbarkeit, f
• Strombelastbarkeit, f

FR

• courant admissible, m
• courant permanent admissible, m

 

(длительный) допустимый ток
Максимальное значение электрического тока, который может протекать длительно по проводнику, устройству или аппарату при определенных условиях без превышения определенного значения их температуры в установившемся режиме
[ ГОСТ Р МЭК 60050-826-2009]

Этот ток обозначают I_Z
[ ГОСТ Р 50571. 1-2009 ( МЭК 60364-1: 2005)]

EN

(continuous) current-carrying capacity
ampacity (US)
maximum value of electric current which can be carried continuously by a conductor, a device or an apparatus, under specified conditions without its steady-state temperature exceeding a specified value
[IEV number 826-11-13]

ampacity
The current in amperes that a conductor can carry continuously under the conditions of use without exceeding its temperature rating.
[National Electrical Cod]

FR

courant (permanent) admissible, m
valeur maximale du courant électrique qui peut parcourir en permanence, un conducteur, un dispositif ou un appareil, sans que sa température de régime permanent, dans des conditions données, soit supérieure à la valeur spécifiée
[IEV number 826-11-13]

Ampacity, the term is defined as the maximum amount of current a cable can carry before sustaining immediate or progressive deterioration. Also described as current rating or current-carrying capacity, is the RMS electric current which a device can continuously carry while remaining within its temperature rating. The ampacity of a cable depends on:

• its insulation temperature rating;
• conductor electrical properties for current;
• frequency, in the case of alternating currents;
• ability to dissipate heat, which depends on cable geometry and its surroundings;
• ambient temperature.

Electric wires have some resistance, and electric current flowing through them causes voltage drop and power dissipation, which heats the cable. Copper or aluminum can conduct a large amount of current before melting, but long before the conductors melt, their insulation would be damaged by the heat.

The ampacity for a power cable is thus based on physical and electrical properties of the material & construction of the conductor and of its insulation, ambient temperature, and environmental conditions adjacent to the cable. Having a large overall surface area may dissipate heat well if the environment can absorb the heat.

In a long run of cable, different conditions govern, and installation regulations normally specify that the most severe condition along the run governs the cable's rating. Cables run in wet or oily locations may carry a lower temperature rating than in a dry installation. Derating is necessary for multiple circuits in close proximity. When multiple cables are near, each contributes heat to the others and diminishes the amount of cooling air that can flow past the individual cables. The overall ampacity of the insulated conductors in a bundle of more than 3 must be derated, whether in a raceway or cable. Usually the de-rating factor is tabulated in a nation's wiring regulations.

Depending on the type of insulating material, common maximum allowable temperatures at the surface of the conductor are 60, 75 and 90 degrees Celsius, often with an ambient air temperature of 30°C. In the U.S., 105°C is allowed with ambient of 40°C, for larger power cables, especially those operating at more than 2 kV. Likewise, specific insulations are rated 150, 200 or 250°C.

The allowed current in cables generally needs to be decreased (derated) when the cable is covered with fireproofing material.

For example, the United States National Electric Code, Table 310-16, specifies that up to three 8 AWG copper wires having a common insulating material (THWN) in a raceway, cable, or direct burial has an ampacity of 50 A when the ambient air is 30°C, the conductor surface temperature allowed to be 75°C. A single insulated conductor in air has 70 A rating.

Ampacity rating is normally for continuous current, and short periods of overcurrent occur without harm in most cabling systems. The acceptable magnitude and duration of overcurrent is a more complex topic than ampacity.

When designing an electrical system, one will normally need to know the current rating for the following:

• Wires
• Printed Circuit Board traces, where included
• Fuses
• Circuit breakers
• All or nearly all components used

Some devices are limited by power rating, and when this power rating occurs below their current limit, it is not necessary to know the current limit to design a system. A common example of this is lightbulb holders.

[http://en.wikipedia.org/wiki/Ampacity]

Тематики

• электротехника, основные понятия

Синонимы

• длительно допустимый ток
• допустимый ток

EN

• ampacity (US)
• continuous current
• continuous current-carrying capacity
• current-carrying capacity

DE

• Dauerstrombelastbarkeit, f
• Strombelastbarkeit, f

FR

• courant admissible, m
• courant permanent admissible, m

 

непрерывный ток
—
[Я.Н.Лугинский, М.С.Фези-Жилинская, Ю.С.Кабиров. Англо-русский словарь по электротехнике и электроэнергетике, Москва, 1999]

Тематики

• электротехника, основные понятия

EN

• continuous current

 

(длительный) допустимый ток
Максимальное значение электрического тока, который может протекать длительно по проводнику, устройству или аппарату при определенных условиях без превышения определенного значения их температуры в установившемся режиме
[ ГОСТ Р МЭК 60050-826-2009]

Этот ток обозначают I_Z
[ ГОСТ Р 50571. 1-2009 ( МЭК 60364-1: 2005)]

EN

(continuous) current-carrying capacity
ampacity (US)
maximum value of electric current which can be carried continuously by a conductor, a device or an apparatus, under specified conditions without its steady-state temperature exceeding a specified value
[IEV number 826-11-13]

ampacity
The current in amperes that a conductor can carry continuously under the conditions of use without exceeding its temperature rating.
[National Electrical Cod]

FR

courant (permanent) admissible, m
valeur maximale du courant électrique qui peut parcourir en permanence, un conducteur, un dispositif ou un appareil, sans que sa température de régime permanent, dans des conditions données, soit supérieure à la valeur spécifiée
[IEV number 826-11-13]

Ampacity, the term is defined as the maximum amount of current a cable can carry before sustaining immediate or progressive deterioration. Also described as current rating or current-carrying capacity, is the RMS electric current which a device can continuously carry while remaining within its temperature rating. The ampacity of a cable depends on:

• its insulation temperature rating;
• conductor electrical properties for current;
• frequency, in the case of alternating currents;
• ability to dissipate heat, which depends on cable geometry and its surroundings;
• ambient temperature.

Electric wires have some resistance, and electric current flowing through them causes voltage drop and power dissipation, which heats the cable. Copper or aluminum can conduct a large amount of current before melting, but long before the conductors melt, their insulation would be damaged by the heat.

The ampacity for a power cable is thus based on physical and electrical properties of the material & construction of the conductor and of its insulation, ambient temperature, and environmental conditions adjacent to the cable. Having a large overall surface area may dissipate heat well if the environment can absorb the heat.

In a long run of cable, different conditions govern, and installation regulations normally specify that the most severe condition along the run governs the cable's rating. Cables run in wet or oily locations may carry a lower temperature rating than in a dry installation. Derating is necessary for multiple circuits in close proximity. When multiple cables are near, each contributes heat to the others and diminishes the amount of cooling air that can flow past the individual cables. The overall ampacity of the insulated conductors in a bundle of more than 3 must be derated, whether in a raceway or cable. Usually the de-rating factor is tabulated in a nation's wiring regulations.

Depending on the type of insulating material, common maximum allowable temperatures at the surface of the conductor are 60, 75 and 90 degrees Celsius, often with an ambient air temperature of 30°C. In the U.S., 105°C is allowed with ambient of 40°C, for larger power cables, especially those operating at more than 2 kV. Likewise, specific insulations are rated 150, 200 or 250°C.

The allowed current in cables generally needs to be decreased (derated) when the cable is covered with fireproofing material.

For example, the United States National Electric Code, Table 310-16, specifies that up to three 8 AWG copper wires having a common insulating material (THWN) in a raceway, cable, or direct burial has an ampacity of 50 A when the ambient air is 30°C, the conductor surface temperature allowed to be 75°C. A single insulated conductor in air has 70 A rating.

Ampacity rating is normally for continuous current, and short periods of overcurrent occur without harm in most cabling systems. The acceptable magnitude and duration of overcurrent is a more complex topic than ampacity.

When designing an electrical system, one will normally need to know the current rating for the following:

• Wires
• Printed Circuit Board traces, where included
• Fuses
• Circuit breakers
• All or nearly all components used

Some devices are limited by power rating, and when this power rating occurs below their current limit, it is not necessary to know the current limit to design a system. A common example of this is lightbulb holders.

[http://en.wikipedia.org/wiki/Ampacity]

Тематики

• электротехника, основные понятия

Синонимы

• длительно допустимый ток
• допустимый ток

EN

• ampacity (US)
• continuous current
• continuous current-carrying capacity
• current-carrying capacity

DE

• Dauerstrombelastbarkeit, f
• Strombelastbarkeit, f

FR

• courant admissible, m
• courant permanent admissible, m

 

предельно допустимый ток
—
[Я.Н.Лугинский, М.С.Фези-Жилинская, Ю.С.Кабиров. Англо-русский словарь по электротехнике и электроэнергетике, Москва, 1999 г.]

Тематики

• электротехника, основные понятия

EN

• current capacity
• current-carrying capacity

 

прочность печатной платы к токовой нагрузке
Свойство печатной платы сохранять электрические и механические характеристики после воздействия максимально допустимой токовой нагрузки на печатный проводник или металлизированное отверстие печатной платы.
[ ГОСТ Р 53386-2009]

Тематики

• платы печатные

EN

• current-carrying capacity

SUBJECT AREA: Metallurgy

[br]

[br]

[br]

Several members of Champion's Quaker family were actively engaged as merchants in Bristol during the late seventeenth and the eighteenth centuries. Port records show Nehemiah in receipt of Cornish copper ore at Bristol's Crews Hole smelting works by 1706, in association with the newly formed brassworks of the city. He later became a leading partner, managing the company some time after Abraham Darby left the Bristol works to pursue his interest at Coalbrookdale. Champion, probably in company with his father, became the largest customer for Darby's Coalbrookdale products and also acted as Agent, at least briefly, for Thomas Newcomen.

A patent in 1723 related to two separate innovations introduced by the brass company.

The first improved the output of brass by granulating the copper constituent and increasing its surface area. A greater proportion of zinc vapour could permeate the granules compared with the previous practice, resulting in the technique being adopted generally in the cementation process used at the time. The latter part of the same patent introduced a new type of coal-fired furnace which facilitated annealing in bulk so replacing the individual processing of pieces. The principle of batch annealing was generally adopted, although the type of furnace was later improved. A further patent, in 1739, in the name of Nehemiah, concerned overshot water-wheels possibly intended for use in conjunction with the Newcomen atmospheric pumping engine employed for recycling water by his son William.

Champion's two sons, John and William, and their two sons, both named John, were all concerned with production of non-ferrous metals and responsible for patented innovations. Nehemiah, shortly before his death, is believed to have partnered William at the Warmley works to exploit his son's new patent for producing metallic zinc.

[br]

SUBJECT AREA: Railways and locomotives

[br]

[br]

[br]

Brotan, who was Chief Engineer of the main workshops of the Royal Austrian State Railways at Gmund, found that locomotive inner fireboxes of the usual type were both expensive, because the copper from which they were made had to be imported, and short-lived, because of corrosion resulting from the use of coal with high sulphur content. He designed a firebox of which the side and rear walls comprised rows of vertical watertubes, expanded at their lower ends into a tubular foundation ring and at the top into a longitudinal water/steam drum. This projected forward above the boiler barrel (which was of the usual firetube type, though of small diameter), to which it was connected. Copper plates were eliminated, as were firebox stays.

The first boiler to incorporate a Brotan firebox was built at Gmund under the inventor's supervision and replaced the earlier boiler of a 0−6−0 in 1901. The increased radiantly heated surface was found to produce a boiler with very good steaming qualities, while the working pressure too could be increased, with consequent fuel economies. Further locomotives in Austria and, experimentally, elsewhere were equipped with Brotan boilers.

Disadvantages of the boiler were the necessity of keeping the tubes clear of scale, and a degree of structural weakness. The Swiss engineer E. Deffner improved the latter aspect by eliminating the forward extension of the water/steam drum, replacing it with a large-diameter boiler barrel with the rear section of tapered wagon-top type so that the front of the water/steam drum could be joined directly to the rear tubeplate. The first locomotives to be fitted with this Brotan-Deffner boiler were two 4−6−0s for the Swiss Federal Railways in 1908 and showed very favourable results. However, steam locomotive development ceased in Switzerland a few years later in favour of electrification, but boilers of the Brotan-Deffner type and further developments of it were used in many other European countries, notably Hungary, where more than 1,000 were built. They were also used experimentally in the USA: for instance, Samuel Vauclain, as President of Baldwin Locomotive Works, sent his senior design engineer to study Hungarian experience and then had a high-powered 4−8−0 built with a watertube firebox. On stationary test this produced the very high figure of 4,515 ihp (3,370 kW), but further development work was frustrated by the trade depression commencing in 1929. In France, Gaston du Bousquet had obtained good results from experimental installations of Brotan-Deffner-type boilers, and incorporated one into one of his high-powered 4−6−4s of 1910. Experiments were terminated suddenly by his death, followed by the First World War, but thirty-five years later André Chapelon proposed using a watertube firebox to obtain the high pressure needed for a triple-expansion, high-powered, steam locomotive, development of which was overtaken by electrification.

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SUBJECT AREA: Metallurgy

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Paul Héroult, the son of a tanner, at the age of 16, while still at school in Caen, read Deville's book on aluminium and became obsessed with the idea of developing a cheap way of producing this metal. After his family moved to Gentillysur-Bièvre he studied at the Ecole Sainte-Barbe in Paris and then returned to Caen to work in the laboratory of his father's tannery. His first patent, filed in February and granted on 23 April 1886, described an invention almost identical to that of C.M. Hall: "the electrolysis of alumina dissolved in molten cryolite into which the current is introduced through suitable electrodes. The cryolite is not consumed." Early in 1887 Héroult attempted to obtain the support of Alfred Rangod Pechiney, the proprietor of the works at Salindres where Deville's process for making sodium-reduced aluminium was still being operated. Pechiney persuaded Héroult to modify his electrolytic process by using a cathode of molten copper, thus making it possible produce aluminium bronze rather than pure aluminium. Héroult then approached the Swiss firm J.G.Nehe Söhne, ironmasters, whose works at the Falls of Schaffhausen obtained power from the Rhine. They were looking for a new metallurgical process requiring large quantities of cheap hydroelectric power and Héroult's process seemed suitable. In 1887 they established the Société Metallurgique Suisse to test Héroult's process. Héroult became Technical Director and went to the USA to defend his patents against those of Hall. During his absence the Schaffhausen trials were successfully completed, and on 18 November 1888 the Société Metallurgique combined with the German AEG group, Oerlikon and Escher Wyss, to establish the Aluminium Industrie Aktiengesellschaft Neuhausen. In the early electrolytic baths it was occasionally found that arcs between the bath surface and electrode could develop if the electrodes were inadvertently raised. From this observation, Héroult and M.Killiani developed the electric arc furnace. In this, arcs were intentionally formed between the surface of the charge and several electrodes, each connected to a different pole of the AC supply. This furnace, the prototype of the modern electric steel furnace, was first used for the direct reduction of iron ore at La Praz in 1903. This work was undertaken for the Canadian Government, for whom Héroult subsequently designed a 5,000-amp single-phase furnace which was installed and tested at Sault-Sainte-Marie in Ontario and successfully used for smelting magnetite ore.

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 The combustor is located immediately ahead of the gas turbine.

 A pressure tap is provided just ahead of the nozzle throat.

 The two modules are mounted just forward of the ball screw actuator.

 Immediately before the initiation of a data run, the mass of each plate was measured with the Mettler balance.

 The temperature of the naphthalene was sensed by a pair of copper-constantan thermocouples positioned just beneath the exposed surface.

 The motor just below and to the left adjusts the initial position of the drill by turning the gear below it.

 The q parameter is adjusted by rotating the grinding head about the pivot point that is just behind the socket in the lower center.

 The hot junction of the thermocouple shall be located immediately to the rear of the cones.

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SUBJECT AREA: Paper and printing

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Soon after his birth, Senefelder's family moved to Mannheim, where his father, an actor, had obtained a position in the state theatre. He was educated there, until he gained a scholarship to the university of Ingolstadt. The young Senefelder wanted to follow his father on to the stage, but the latter insisted that he study law. He nevertheless found time to write short pieces for the theatre. One of these, when he was 18 years old, was an encouraging success. When his father died in 1791, he gave up his studies and took to a new life as poet and actor. However, the wandering life of a repertory actor palled after two years and he settled for the more comfortable pursuit of playwriting. He had some of his work printed, which acquainted him with the art of printing, but he fell out with his bookseller. He therefore resolved to carry out his own printing, but he could not afford the equipment of a conventional letterpress printer. He began to explore other ways of printing and so set out on the path that was to lead to an entirely new method.

He tried writing in reverse on a copper plate with some acid-resisting material and etching the plate, to leave a relief image that could then be inked and printed. He knew that oily substances would resist acid, but it required many experiments to arrive at a composition of wax, soap and charcoal dust dissolved in rainwater. The plates wore down with repeated polishing, so he substituted stone plates. He continued to etch them and managed to make good prints with them, but he went on to make the surprising discovery that etching was unnecessary. If the image to be printed was made with the oily composition and the stone moistened, he found that only the oily image received the ink while the moistened part rejected it. The printing surface was neither raised (as in letterpress printing) nor incised (as in intaglio printing): Senefelder had discovered the third method of printing.

He arrived at a workable process over the years 1796 to 1799, and in 1800 he was granted an English patent. In the same year, lithography (or "writing on stone") was introduced into France and Senefelder himself took it to England, but it was some time before it became widespread; it was taken up by artists especially for high-quality printing of art works. Meanwhile, Senefelder improved his techniques, finding that other materials, even paper, could be used in place of stone. In fact, zinc plates were widely used from the 1820s, but the name "lithography" stuck. Although he won world renown and was honoured by most of the crowned heads of Europe, he never became rich because he dissipated his profits through restless experimenting.

With the later application of the offset principle, initiated by Barclay, lithography has become the most widely used method of printing.

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The isotopic ratio of the lead is measured with (or by) a photoelectric cell.

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There is no way of gauging the external gravitational field.

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 The cylinder temperature was measured with a calibrated copper-constantan thermocouple in conjunction with a 0.1°F ASTM-certified thermometer.

 The air was metered by one of two calibrated sharped-edged orifices.

 The heat transfer data on the prototype was to be taken at mid span.

 Thermocouple emfs were read with a Hewlett-Packard 3465A digital multimeter with a smallest digit of 1 mV.

 The pressure signals were sensed by a Baratron solid-stale capacitance-type meter capable of being read to as low as 10-3 torr.

 The impact-static pressure difference was detected by a Baratron meter capable of discriminating 10-3 mm Hg.

 The oil flow was determined with a calibrated cylinder and a stopwatch.

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