AGK Systems - Fire and Smoke protection and detection

Question 1

Two types of smoke detection

Answer 1

Optical and ionising

Question 2

Optical Smoke Detector

Answer 2

Compromises of a light and a sensor

Arranged so the during a normal condition, the sensor cannot detect the light

If smoke particles are present, they are reflected off the light and trigger a warning on FD

Question 3

Ionising Smoke Detection

Answer 3

Question 4

Loop Engine Fire Detection

Answer 4

Continuous loop system, AKA fire wire

Nickel core surrounded by coating of eutectic salt

AC

Increase temp, resistance of salt decreases

Change in resistance combined with change in capacitance

Produces fire signal when current reaches predetermined level

Question 5

Detection Loops

Answer 5

Engines equipped with a pair of fire detection loops and a pair of overheat section loops

Loops wound in and around components on engine casing

Both loops (A + B) must detect a fire

If fault is detected, amber FAULT caption illuminates

Selecting faulty loop off, restores fire detection capability

Question 6

Systron Donner System

Answer 6

Double gaseous loop located around the fire zone

Stainless steel tube around a gas absorbing material

Heating causes the absorbed gas to escape and increase the pressure in the tube

A bellows is sensitive to pressure increase and closes 2 switch contacts - trigger an alarm

Both loops must detect a signal to trigger an Alarm

Question 7

Bimetallic Overheat Sensor

Answer 7

Question 8

Can the Fire Suppression System be reset?

Answer 8

Yes

The IDG is not disconnected so that the engine can be re-lit