Technical data

Test Considerations

To ensure proper instrument operation, verify that you have selected

the correct power-line voltage prior to attempting any test procedure in

this chapter. See chapter 2, “Quick Start,” for more information.

Ensure that all measurement terminal connections (both front panel

and rear panel) are removed while the multimeter’s internal self-test is

being performed. Errors may be induced by ac signals present on the

multimeter’s input terminals during a self-test. Long test leads can also

act as an antenna causing pick-up of ac signals.

For optimum performance, all test procedures should comply with the

following recommendations:

• Assure that the calibration ambient temperature is stable and

between 18

°C and 28°C.

• Assure ambient relative humidity is less than 80%.

• Allow a 2-hour warm-up period before verification or adjustment.

• Use only copper connections to minimize thermal offset voltages.

• Use shielded twisted Teflon

insulated cable to minimize high

resistance errors.

• Keep cables as short as possible.

• Allow 5 minutes after handling input connections for thermal offset

voltage settling.

Because the multimeter is capable of making highly accurate

measurements, you must take special care to ensure that the calibration

standards and test procedures used do not introduce additional errors.

Ideally, the standards used to test and calibrate the multimeter should

be an order of magnitude more accurate than each multimeter range full

scale error specification.

For dc voltage, dc current, and resistance measurements, you should

take care to ensure that the calibrator’s “0” output is correct. If necessary,

the multimeter measurements can be referenced to the calibrator’s “0”

output using the multimeter’s front-panel

NULL function. You will need

to repeat this procedure for each range of the measuring function being

verified.

Chapter 4 Calibration Procedures

Test Considerations