User manual

Part B Section 12.31
10 CYLINDER HEAD TEMPERATURE GAUGES
The cylinder head temperature gauges are electrically operated and protected through a
circuit breaker on the Co-Pilot's Switch Panel.
The leads to these instruments are cut to an exact length with the excess being coiled into
squares, and stowed in the Pylon compartment. The leads should not be cut and
shortened; otherwise the readings to the thermo- coupled instruments will be in error.
The thermo- couples are mounted under the Number 1 cylinder rear spark plug.
11 ENGINE OIL TEMPERATURE GAUGES
The oil temperature gauges operate electrically and are protected by the Electrical
Instrument circuit breaker on the Co-Pilots Switch Panel.
The systems are of a resistance bulb type, with the bulbs being mounted in the rear of the
crankcase to complete a Wheatstone bridge circuit.
12 TACHOMETERS
The tachometers have their own transmitter mounted on the rear of the engine. The
transmitter consists of a small generator which produces voltage in proportion to the
engine RPM.
The receiver is a small instrument which reads the generated voltage with the scale
graduated to read engine RPM.
Note that the propellers rotate slower than the engine at a ratio of 16:9
The instruments are not fused or protected
Stichting Catalina PH-PBY Rev No: 00
18 May, 2004 Page: 3