TB 9-4920-454-24
NOTE
When LED display is flashing, an over-range condition exists.
The reading is incorrect.
8. Temperature Indicator
a. Performance Check
(1) Connect equipment as shown in figure 2.
TEST INSTRUMENT
CALIBRATOR
CHECK CABLE
OUTPUT
RED
HI
LO
BLUE
AIRCRAFT T.C.
THERMOMETER
BH277 *
LEADS
RED
-
BH123-3 *
(SWITCH BOX)
+
BLUE
JETCAL
BH450 *
* SUPPLIED WITH TEST INSTRUMENT
Figure 2. Temperature indicator check.
(2) Position controls as listed in (a) through (e) below:
T/C INPUT switch to CHECK CABLE.
(a)
FUNCTION SELECT switch to TRIM.
(b)
TEMPERATURE CAL ADJ to mid-position.
(c)
TEMPERATURE switch to OPERATE.
(d)
SW-5 switch (located on BH 123-3 switch box) to JETCAL.
(e)
(3) Place thermometer adjacent to calibrator OUTPUT terminals. Wait 10 minutes
for thermometer to stabilize and record ambient temperature.
