Fluke 5720A service manual DC Voltage Verification Test

5700A/5720A Series II Calibrator

Service Manual

3-18. DC Voltage Verification Test

The following test checks every dc voltage range by testing the output accuracy at decade values of voltage from 100 mV to 1000V. Use Table 3-18 (5720A) or Table 3-19 (5700) for the test record. Table 3-5 lists equipment required for this test as well as the Linearity Test that follows. See Table 3-15, Minimum Use Requirements, for equipment substitution information.

Table 3-5. Equipment Required for DC Voltage Testing

Equipment

DC Reference Standard

Reference Divider

Null Detector

Low Thermal Cables

Model

Fluke 732B

Fluke 752A

EM Electronics 11 (Fluke 845A)

5440A-7002

5440A-7003

Note

The 5440A-7002 or 5440A-7003 is for the 5700A; the 5720A uses only the 5440A-7003.

Proceed as follows to perform the dc voltage verification test:

1.Self-calibrate the reference divider in accordance with its instruction manual prior to proceeding.

2.Connect the equipment as shown in Figure 3-5.

3.Set the reference divider to 0.1V. Set the Calibrator to the certified value of the dc reference standard divided by 100. For example, if the certified value of the dc reference standard is 10.000007V, set the Calibrator to 100.00007 mV.

4.Press OPR/STBY. After the reading has settled, verify that the null detector reads 0V ±1.20 μV (5720A 90-day specification) or 0V ±1.45 μV (5700A 90-day specification). Set the Calibrator to standby.

5.Repeat the above process to test each dc voltage range output listed in Tables 3-23 or 3-24. (0.1V is in the table for completeness; you do not need to repeat it.) After the null detector reading stabilizes, ensure that any observed meter rattle (over and above the null detector rattle in the "zero" position) over a ten-second period does not exceed the amount shown in the last column. In each case, set the 5720A to standby before changing to the next voltage settings and go back to operate before reading the null detector.

6.Reverse the connections of the dc reference standard at the reference divider and repeat the previous measurement process for the -0.1V, -1V and -10V outputs.

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