What are initiating Devices?

In an other article, we were introduced to the Fire Alarm System. The system actually is a fulfilling compact loop in itself which actually frees manual intervention & dependence to a substantial amount. It works with the help of some smart devices. But here too, the first input is the instance of Fire and then the rest of the system. So the first set of devices are the Initiating Devices. They are the ones which actually sense that there is a danger. Without them, you can’t predict that there is a fire. Let’s understand what are Initiating Devices in a little more depth:

Typical Initiating Devices are:

1. Smoke Detectors:
Smoke Detectors detect Smoke in the premise & initiate the further system. There are 3 types used:-

(A)Ionization Type:

Ionization Smoke detector_Final Image (002) In this type of a smoke detector, you will find an ionization chamber, which consists of very small amount of Americium-241, which is a radioactive Isotope. When smoke enters any premise, an electric current is created & signals are passed to the further system.

The Video above demonstrates how a Photoelectric Smoke Detector works.
It mainly detects the difference in light inside the room or premises. These are the most widely used Smoke detectors. (
Refer this article)
Photo electric type smoke detector can detect the smoke by a couple of infrared diodes. The principal of detecting is particle in the smoke can reflect infrared lights. The chamber can shield external light, but does not affect the smoke into it. While there is no smoke the diode can receive very week infrared light. When the smoke enters in the chamber diode can receive more and more light and the detector can give out alarm single when the smoke reaches the certain density.
Photoelectric smoke detector_Final (002)

(C) Dual Type:

These are the combo type where Ionization & Photoelectric smoke detectors are smartly used. It balances the usage to alert the system smartly.
Ionization Smoke detector_Final Image (002)

2. Heat Detectors:

Heat Detectors actually track if there is a major Temperature Difference within the premise. There are Fixed Temperature Heat Detectors & Rate of Rise (ROR) Heat Detectors.

The Fixed Temperature Heat Detectors contain Eutectic Alloy, which actually changes its state from Solid to Liquid with the rise of temperature. So this initiates a following system

The Rate of Rise Heat Detectors, unlike the Fixed Temperature Heat Detectors, work on the variation of temperature tracks. In a minute if it observes rapid temperature difference from 6.7 to 8.3 degrees, it will initiate the follow up system.

Details of these can be seen at this article in Wikipedia.

3. Manually operated pull stations:
Manually operated pull stations 1 (002)

A Manually operated pull station is a device, usually wall-mounted, by pulling the handle down or up, initiates an alarm. In its simplest form, the user activates the alarm by pulling the handle down, which completes a circuit and locks the handle in the activated position.
Are they still in operation? Yes and No. Read
this article for more details.

4. Sprinkler water flow sensors:

Sprinkler Shower Sensor is a device on which a Transparent bulb containing Red Alcohol is mounted. When the surrounding temperature in the room goes beyond 580c; the Bulb bursts. Immediately the Water in the pipeline starts sprinkling in the room. This gives an indication to the Control Panel through the Flow Switch to actuate the Fire Alarm System.Sprinkler water flow sensors. 2 (002)
These are some of the major Initiating Devices used in a Fire Alarm System. Many companies, manufacturers and system providers come up with their own smart designs.
At Vighnaharta, we strongly believe in offering a very flexible, yet technically appropriate solution to our clients. Please
contact us so that our team will find out what will be the best solution for you.