This thermal probe detector has an alarm activation temperature of 90°C (194°F). The detector is made to withstand harsh outside environments. It can be vertically mounted, and is moisture and dustproof. The detector has a plastic bushing with conduit threads for attachment to a hub cover, or any outlet junction box.
The automatic heat detector is designed for rapid-fire detection with alarm systems. The detectors are normally open devices and are a “rate compensation type” detectors. This model is self-restoring, hermetically sealed, shock and corrosion-resistant, nonferrous, and tamperproof.
Principles of Operation
This model operates on the principles of a rate compensation detector. The detector consists of a high expansion aluminium tube that encases two insulated struts with opposing open contact points. The high expansion sensing shell and the expansion struts have a different coefficient of expansion. This allows the detector to react to changes in temperature in the following two ways:
– Slow Rate of Temperature Rise – Allows the heat to penetrate the inner expansion struts. As the temperature rises, the tubular shell and the struts both expand until the total device has been heated to the rated temperature. At this point, the silver contact points close, which initiates the alarm.
– Rapid Rate of Temperature Rise – When subjected to a rapid rise in temperature, there is not as much time for heat to penetrate the inner strut. The rapid lengthening of the shell along with the slower reaction of the struts allow the silver contact points to close at a lower level. The detector reacts almost instantly to the rapid increase in temperature and “compensates” for thermal lag inherent in conventional fixed temperature detectors.
When the ambient air temperature drops below the detector’s rated temperature, the shell contracts which forces the contacts to open and the detector to reset itself.
Maintenance
The Thermal Probe Detector is low maintenance; detectors automatically restore when temperatures drop below their rated temperatures. Accumulation of dust and dirt should not adversely affect detectors. If detectors must be cleaned for aesthetic purposes, turn the alarm system off and clean detectors with a damp cloth.
Looking for the Explosive Proof version of the Thermal Probe Detector, click here: 404-TPX-90C.
