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Service Information
4-16
b)
For “Measure DC Volts Channel 2”, Calculate the limits of error by
adding/subtracting the value noted in the “Tolerance” column to the value of
the “Standard” column for each setpoint. A
PASS
result is any “Measurement
Result” value that is equal to or in between the Lower Limit and Upper Limit
error numbers.
10.
Enter setup mode,
(1.5s)
and ensure the following parameters are set: units =
“mV” and rAnGE = “Lo”.
11.
By using the
and/or
keys, adjust the instrument Source to match
each value in Figure 12 in the “Low range”, notating the result from the DMM on
the “Instrument Verification Data Sheet”, Appendix C in “Source DC Volts Channel
1” “Measurement Result” and “Measure DC Volts Channel 2” “Standard” column.
12.
Pass/Fail Criteria:
c)
For “Source DC Volts Channel 1”, a
PASS
result is any “Measurement Result”
value that is equal to or in between the Lower Limit and Upper Limit error
numbers.
d)
For “Measure DC Volts Channel 2”, Calculate the limits of error by
adding/subtracting the value noted in the “Tolerance” column to the value of
the “Standard” column for each setpoint. A
PASS
result is any “Measurement
Result” value that is equal to or in between the Lower Limit and Upper Limit
error numbers.
13.
To verify the Cold Junction Compensation, (CJC) of the Source, (Channel 1) and
Read, (Channel 2).
14.
Place the CL940A in a Controlled Environment
10
along with an accurate
thermometer
11
for one hour to stabilize. Compare CJC readings with the reference
thermometer reading. Display the CJC temperature by pressing
(1.5s)
. The
screen will display “CJC 1” and the current temperature of CJC 1 in °C. Pressing
the
key again will display “CJC 2” and the current temperature of CJC 2 in °C.
Notate the results in the “Cold Junction Compensation” section on the Instrument
Verification Data Sheet, placing the Thermometer reading in the “Standard”
column, and the CJC readings in the “Measurement Result” column. Select
to
exit.
10
An insulated box inside a calibration lab environment, see Appendix A.
11
An accurate thermometer specification is 2 Sigma uncertainty ≤ .04°C (40mK) at the verification
temperature.
Summary of Contents for CL940A
Page 39: ...Appendices B iii Thermocouple Type K ...
Page 40: ...Appendices B iv ...
Page 41: ...Appendices B v Thermocouple Type J ...
Page 42: ...Appendices B vi ...
Page 43: ...Appendices B vii Thermocouple Type T ...
Page 44: ...Appendices B viii ...
Page 45: ...Appendices B ix Thermocouple Type E ...
Page 46: ...Appendices B x ...
Page 48: ...Appendices B xii ...
Page 50: ...Appendices B xiv ...
Page 51: ...Appendices B xv Thermocouple Type R ...
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Page 55: ...Appendices B xix Thermocouple Type G ...
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Page 59: ...Appendices B xxiii Thermocouple Type D ...
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