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Unformatted text preview: itored close to the detection chamber. When no smoke in air then no light is visible. When there is a smoke the light strikes it can be seen in the window along with a green indication on the front of the detector. OVER HEAT AND FIRE DETECTION SYSTEM. Detector element consists of stainless tube protected throughout its length by Teflon coating inside the tube is metal hydride coated element surrounded by inert gas (Helium) one end is closed other end is bifurcated and joined to two diaphragm operated pressure switches. One is open other is kept closed by normal pressure 20 PSI. System is designed to sense two levels of temperature then there must be two detecting elements each with different sensing levels. One pair is over heat loop other pair is fire loop. Located at the bottom of engine or engine: of fire wall. If the local temp rises to 205 ± 30°C the coating of the element inside on over heat releases the gas Hydrogen. This increases the pressure inside the tube so that diaphragm of normally open switch will close its contacts the signal now flowing from the contact passes through operational amplifier output of which biases the transi...
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This note was uploaded on 03/09/2011 for the course AIRCRAFT 2008.09.00 taught by Professor Dr.alan during the One '11 term at TAFE NSW - Sydney Institute.
- One '11