How Does a Mechanical Fire Alarm Work?

Fixed Temperature

• One type of mechanical fire alarm operates based on the detection of a preset fixed temperature. The temperature is usually somewhere around 135 degrees Fahrenheit, although it can differ slightly from one manufacturer to another. The fixed temperature mechanical fire alarm works by responding to the heat in the home. The materials in the alarm that respond to the heat are designed to turn from a solid to a liquid state when the temperature reaches a specific level. This, in turn, trips the alarm.

Rate of Rise

• A second type of mechanical fire alarms is one that responds to the rate at which the temperature in the home rises. This type of alarm generally responds to changes of about 12 to 15 degrees Fahrenheit over the span of about one minute. One of the positives of this type of detector is that it will sound off even if you start at a low temperature, as long as the temperature in the house rises quicker than it would were a fire not present.

Dual Detectors

• Both types of detectors have advantages over the other. However, it is possible to purchase mechanical fire alarms that have both the fixed temperature and the rate-of-rise alarm system built into them. These types of alarms are set up on separate circuits so that they can work independently of one another, making it possible for one to serve as a potential fail-safe for the other. You can tell if your detector contains both types of alarms because it has "FX/ROR" written somewhere on the outside of the alarm.

Installation

• Installation of mechanical fire alarms is fairly simple. These differ little from smoke detectors in the way that they are installed. They can likewise be installed in various locations throughout the home to ensure the safety of the inhabitants. Installation involves removing the alarm from its mounting bracket and installing the bracket into the desire wall or ceiling with couple of wood screws. The detector is then installed by simply placing it in the mounting bracket and turning it clockwise until it clicks into place.