TM 10-1670-305-23&P
ELECTRONIC TEST CHAMBER ASSEMBLY, MODEL 453
0025 00
DIRECT SUPPORT MAINTENANCE
CALIBRATION AND ADJUSTMENT
WARNING
Calibration of and adjustment to the control assembly may be made only by an
authorized calibration laboratory or repair facility with proper altitude-measuring
standard instrument.
NOTE
If the control assembly cannot be brought into tolerance, it is defective and must
be replaced.
ALTITUDE ACCURACY VERIFICATION
NOTE
Standard instrument used to verify altitude accuracy shall have a verified
accuracy within 0.01 % full scale.
1. Position test chamber assembly near 110 VAC power outlet and a standard instrument.
2. Control ambient temperature to 68 9F (20 5C).
3. Use calibration adapter to connect calibration port on control assembly with standard
instrument. A 1/8-in. male connector is provided with the calibration adapter to connect it to
standard instrument.
4. Connect test chamber assembly to 110 VAC, 50/60 Hz power source.
5. Turn on both instruments and allow them to warm up for 30 minutes minimum.
6. Use SET ALTITUDE CONTROL on control assembly so that standard instrument reads
within 5 feet of the first value in Table 1. If calibration facility is at high altitude. It may be
necessary to clamp the lid of the altitude chamber to effect a seal (refer to WP 0012 00).
0025 00-1
Change 1
