Kiinteälämpötilailmaisimet

Kiinteälämpötilailmaisimet, often translated as fixed temperature detectors, are a type of fire detection device that triggers an alarm when a specific, predetermined temperature is reached. Unlike rate-of-rise detectors that respond to a rapid increase in temperature, these devices rely solely on the ambient temperature exceeding a set threshold. This makes them suitable for environments where a steady, high temperature is expected, rather than a sudden flash fire.

The operation of a kiinteälämpötilailmaisin is based on a simple thermometric principle. Typically, a bimetallic strip or a heat-sensitive fusible link is used. In a bimetallic strip design, two different metals with varying thermal expansion coefficients are bonded together. As the temperature rises, one metal expands more than the other, causing the strip to bend. This bending action can be used to close an electrical circuit, activating the alarm system. Fusible links, on the other hand, are designed to melt at a specific temperature. When the link melts, it releases a mechanism that completes the alarm circuit.

These detectors are commonly found in areas where a fire is likely to produce a significant amount of heat before flames become visible, such as kitchens, boiler rooms, and industrial settings. Their reliability and simplicity make them a cost-effective choice for many applications. However, their slower response time compared to smoke detectors means they are not ideal for situations where immediate detection of smoldering fires is crucial for life safety. The activation temperature is a critical specification, chosen based on the expected normal operating temperatures of the environment to avoid false alarms while ensuring timely detection.