De Havilland DASH8 100 Series Maintenance Manual page 60

exceeds 810 degrees C. The lamp and its associated switch are connected into test and
dim unit circuits.
A test pushbutton is provided in each indicator, which when pressed, with indicating
system power on, causes the indicator pointer to move to 1050 degrees C, indicated by
the dial, a blue dot on the face of the indicator dial and an equivalent digital display.
Releasing the test pushbutton causes the indicator pointer to return to its original setting,
with an equivalent digital display.
In the event of loss of electrical power to the indicator, the indicator pointer moves off
scale below zero and the digital display is blanked.
MASTER
EFFECTIVITY: See Pageblock 77−20−00 page 1
D
S ERIES 100
AIRCRAFT MAINTENANCE MANUAL
77−20−00
Dec 20/2004
Page 2