XPA-CB-11170 Xpander Rate of Rise Heat Detector (With Mounting Base)The Xpander Rate of Rise heat detector is used in conditions in which smoke detectors are unsuitable. It should be be considered for use if there is a danger of nuisance alarms from smoke detectors. Rate of Rise detectors have a fixed upper limit, but they also measure the rate of increase in temperature. A Rate of Rise detector is to be preferred to a static heat detector unless sharp increases in temperature are part of the normal environment in the