Motors on the milling heads are totally enclosed

Extensive baffling is used to prevent laser scatter reaching the photomultipliers.

In a fast crosswind the wing cannot be raised quickly enough to forestall a skid.

Motors on the milling heads are totally enclosed to exclude (or prevent, or guard against) ingress of metallic dust.

A duplicate radar system is the obvious way to guard against the possibility of grounding due to equipment failure.

The installation insures against dehydration of the gypsum.

The resulting gyroscopic stabilization keeps the projectile tumbling.

The filter keeps stray radio-frequency signals entering the amplifier.

The closed vacuum system precludes oxidation.

The presence of titanium prevents the formation of martensite.

The non-return valve prevents air being drawn back into the main-pump suction.

This requires shutdown of the reactor to safeguard it against the release of contaminants.

The rams are situated on the outside of the main chassis members to ensure that no twisting arises at...

Properly executed roof bolting will inhibit loosening.

To prevent water entering is one of the aims of mine drainage.

Adhesives seal against entrapment of moisture between surfaces....

The counter-gravity flow of the inhaled air reduces the entry of heavier dust particles into the filtering medium.

Motors on the milling heads are totally enclosed to exclude ingress (or penetration) of metallic dust generated by the cutters.