TM 55-4920-401-13&P
finite resistance and RESISTANCE CHECK meter
should be indicating 0 ohms.
(3) Examine the instrument case lid for the
condition of the instruction plate, the inclusion of
spare heater probe controller fuses, and the inclu-
sion and condition of the ambient temperature ther-
mometer.
b. Functional Inspection. If a malfunction is
detected during the functional inspection, refer to
table 3-2 for the probable cause and corrective ac-
tion.
NOTE
L a m p c a p s a r e i n t e r c h a n g e a b l e .
PROBE POWER and POWER ON caps
are red. STD DAY cap is yellow.
CAUTION
Do not interchange STD DAY lamp
with POWER ON or PROBE POWER
lamps. STD DAY lamp is 28V while
the others are 115V.
(1) Turn FUNCTION SELECT, STD DAY,
and MASTER POWER switches to OFF position.
(2) Connect BH499A power cable to POWER
INPUT receptacle and to 115 vat, 50-400 Hz power
source.
(3) Connect BH15184A power interconnect
cable to two INTERCONNECT connectors on tester
deck.
(4) Turn MASTER POWER switch to ON
position and allow 15 minute warmup. POWER ON
lamp shall light and displays shall light.
(5) Press PRESS TO TEST switch. All digits
shall read "8".
(6) Turn TEMPERATURE switch to CAL
600° C position. Tester shall read 600 (± 2) ºC. See
step 8.
(7) Turn RPM switch to CAL 100° RPM
position. Tester shall read 100 (± 1) % RPM. See
step 8.
( 8 ) A d j u s t a p p l i c a b l e C A P A D J
potentiometer to bring each indicator within
tolerances listed in steps 6 and 7. If an indicator
cannot be calibrated by adjusting applicable CAL
ADJ potentiometer, indicator shall be calibrated.
(9) With TEMP and RPM switches in CAL
positions, note readings of TEMP and % RPM
indicators.
(10) Adjust AMB TEMP control for a 59° F
reading in window.
NOTE
STD DAY lamp should flash in next
step indicating switches are not in
correct positions for making standard
day measurements.
(11) Turn STD DAY switch to ON position.
TEMP and % RPM indicator readings shall not
change by more than ± 2°C and ± 0.1 % RPM re-
spectively. If readings are not in tolerance, the stan-
dard day circuit shall be calibrated.
(12) Turn STD DAY switch to OFF position.
(13) Turn FUNCTION SELECT switch to A/C
IND CHK position.
(14) T u r n T E M P E R A T U R E s w i t c h to
OPERATE position.
(15) Observe that TEMP indicator reading is
stable and that clockwise rotation of A/C IND ADJ
causes reading to increase and that adjustment
covers the range from ambient through 1399° C.
( 1 6 ) T u r n P R O B E
counterclockwise.
(17) Turn T/C INPUT
CABLE position.
(18) Turn FUNCTION
HEATER PROBE position.
(19) C o n n e c t h e a t er
CABLE receptacle.
C O N T R O L f u l l y
switch to HEATER
SELECT switch to
c a b l e t o H E A T ER
(20) Connect junction box to heater cable.
(21) Connect one heaer probe to junction box.
(22) T u r n T E M P E R A T U R E s w i t c h to
HEATER PROBE TEMP SET and adjust PROBE
CONTROL until TEMP indicator displays 60° C
(140° F).
(23) Turn TEMPERATURE switch to OPER-
ATE position and monitor probe temperature as
probe heats up.
(24) Observe PROBE POWER lamp for
normal probe controller operation. Lamp burns
steadily when probe is heating, extinguishes when
probe is cooling, and flashes when probe is
regulating at set temperature.
(25) Disconnect probe from junction box and
connect another probe, using a different junction
box connector.
(26) Determine that heater probe is heating
by observing TEMP indicator.
(27) Repeat steps 25 and 26 until all probes
and junction box connectors have been tested.
3-3