kiinteälämpötilailmaisimina

Kiinteälämpötilailmaisimet, often translated as fixed-temperature detectors or fixed-point detectors, are a type of fire alarm device. They are designed to trigger when the ambient temperature reaches a predetermined, fixed threshold. Unlike rate-of-rise detectors which respond to a rapid increase in temperature, fixed-temperature detectors are solely based on the absolute temperature value.

These devices are typically bimetallic strips or eutectic alloy devices. In a bimetallic strip, two metals with different thermal expansion coefficients are bonded together. When heated, 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. Eutectic alloys melt at a specific, fixed temperature. When the alloy melts, it changes its physical state, often allowing a contact to close and signal an alarm.

Kiinteälämpötilailmaisimet are a simple and reliable technology, often used in environments where a fire is expected to cause a consistent and significant temperature rise before spreading. They are less prone to false alarms caused by steam or exhaust fumes, which might trigger rate-of-rise detectors. However, their disadvantage is their slower response time compared to rate-of-rise detectors, as they require the temperature to reach the specific set point before activation. Common applications include kitchens, boiler rooms, and industrial settings where consistent heat is a factor. They are often combined with other types of detectors to provide comprehensive fire detection coverage.