All the shopping malls there have heat detector arches at the entrance and bottles of hand gel are everywhere.

This type of heat detector can operate at a lower temperature fire condition than would be possible if the threshold were fixed.

In that case the rate-of-rise heat detector may be preferred.

Each type of heat detector has its advantages, and it can not be said that one type of heat detector should always be used instead of another.

Wakes are minimised and engines are designed to be invisible to heat detectors.