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TM 55-6695-220-13&P
OFF position and disconnect the thermocouple clip leads from the indicator. Observe the ambient temperature
registered on the liquid-filled glass thermometer located in the cover of the tester and adjust the indicator to indicate this
ambient temperature prior to returning the unit to storage or service.
g.
Chromel-Alumel Indicator Test Procedures. Follow the preliminary procedures contained in paragraphs 2-1a.
through d. and normalize the indicator using the zero adjust while the TEMPERATURE SELECTOR SWITCH is
positioned to 700ºC or 900ºC according to Table 2-2. Step the TEMPERATURE SELECTOR SWITCH in each direction
and note the differences between tester dial and indicator readings. The indicator service manual should be consulted
concerning the significance of this error and whether the indicator should be returned to service.
h.
Return the TEMPERATURE SELECTOR SWITCH to its normalization position in accordance with Table 2-2.
Set the indicator pointer using the zero adjust to a reading above that of the TEMPERATURE SELECTOR SWITCH by
an amount equal to the ambient temperature read from the liquid-filled glass thermometer. As an example, suppose the
ambient temperature is 22°C and the TEMPERATURE SELECTOR SWITCH setting is 900ºC, then the indicator is
adjusted to read 922ºC. To complete the test return the RESISTANCE AND VOLTAGE FUNCTION SWITCH to the
OFF position before disconnecting the tester clip leads from the indicator.
NOTE
When either the indicator has no zero adjust or the ambient temperature is below 5°C or
above 45ºC (41ºF to 113ºF) these alternate instructions in para. 2-li. shall be followed.
i.
If the conditions in the Note prevail, the indicator normalization setting shall not be made equal to the algebraic
sum of the TEMPERATURE SELECTOR SWITCH setting plus the ambient temperature reading as prescribed in para.
2-1h. It would follow that during the test the indicator readings should be compared with the sum of the TEMPERATURE
SELECTOR SWITCH setting plus the ambient temperature obtained from the liquid-filled glass thermometer.
2-5
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