Technical data

13773-001
77-20
Page 1
TEMPERATURE
1. DESCRIPTION
This section describes that portion of the engine indicating system which indicates temperature. Included
is the EGT/CHT gage and sensors.
A 2¼” combination Exhaust Gas Temperature (EGT) and Cylinder Head Temperature (CHT) indicator is
mounted in the right instrument panel. 28 VDC for instrument operation and lighting is supplied through the
5-amp ENGINE INSTRUMENTS circuit breaker on the Essential Bus.
The EGT pointer sweeps a scale marked from 1250° F to 1650° F in 25° F increments. The EGT scale has
no limit markings. The EGT indicator receives a temperature signal from a sensor mounted on the No. 4
cylinder exhaust pipe.
The CHT pointer sweeps a scale marked from 200° F to 500° F. The CHT indicator receives a temperature
signal from a sensor mounted in the No. 6 cylinder head.
2. MAINTENANCE PRACTICES
A. EGT/CHT Gage (See Figure 77-201)
(1) Removal - EGT/CHT Gage
(a) Ensure BAT 1, BAT 2, and AVIONICS master switches are in off position.
(b) Pull ENGINE INSTRUMENT circuit breaker.
(c) Remove glareshield. (Refer to 25-10)
(d) Locate and disconnect EGT/CHT gage electrical connector.
(e) While supporting EGT/CHT gage, remove screws securing unit to instrument panel. and
remove from airplane.
(2) Installation - EGT/CHT Gage
(a) Position EGT/CHT gage in instrument panel and attach with screws.
(b) Attach electrical connector.
(c) Install glareshield. (Refer to 25-10)
(d) Reset ENGINE INSTRUMENT circuit breaker.
B. EGT Sensor (See Figure 77-201)
CAUTION: Protect openings exposed as a result of removing sensor against entry of foreign mate-
rial by installing covers or sealing with tape.
(1) Removal - EGT Sensor
(a) Ensure BAT 1, BAT 2, and AVIONICS master switches are in off position.
(b) Pull ENGINE INSTRUMENT circuit breaker.
(c) Remove engine cowling. (Refer to 71-10)
(d) Remove insulation covering EGT sensor wiring and disconnect.
(e) Remove clamp securing sensor assembly to exhaust pipe.
(f) Remove sensor seal, sensor thimble, sensor, and clamp from exhaust pipe.
(2) Installation - EGT Sensor
(a) Position seal, thimble, and clamp over exhaust pipe hole.
(b) Tighten clamp securing components to exhaust pipe.
(c) Insert and firmly press sensor into thimble until Sensor snap into place.
(d) Place insulation over EGT sensor wire, connect sensor lead to harness, slide insulation
over junction and secure with cable ties.
30 Nov 2000