Fluke 5720A service manual Range Calibration

5700A/5720A Series II Calibrator

Service Manual

3-10. Range Calibration

Once calibration is complete, you may find you need to make further adjustments to the range. Calibrating the range is accomplished by adjusting a range constant, which is an additional gain multiplier. Although range calibration is not needed in order to meet total uncertainty specifications, it is useful for tuning the calibrator so that its values are closer to your own standards.

Use your own laboratory standard to adjust the range constants. The following procedure for adjusting the range constants is designed for laboratory standard values that are between 45% and 95% of the range’s full-scale value.

Once you adjust the range constant, the new constant remains active until the next calibration, at which time all range constant multipliers are rest to 1. You can also erase all range adjustments by calling up the format EEPROM menu and selecting Range Constants (refer to Chapter 4 of the 5700A/5720A Operators Manual).

Before you begin the following procedure, make sure you have the equipment you need on hand including your own laboratory standards where required.

The following example procedure adjusts the 220V dc range constant using the following equipment:

∙732B DC reference standard

∙752A Reference Divider

∙845AB/845AR Null Detector

∙Low Thermal Test Leads: 5440A-7002 (banana plugs) or 5440A-7003 (spade lugs)

Warning

Operator accessible LETHAL VOLTAGES may be present on the lugs at the end of the 5440A-7003 cables when used with instrumentation capable of producing such voltages. These cables should be used only when thermal emf performance is required. For other applications, cables with operator protection form contact with high voltages should be used.

Proceed as follows to adjust the 220V dc range constant. You must have completed calibration to external standards before you follow this procedure.

1.Press the “Setup Menus” softkey; the press the “Cal” softkey. The following menu appears:

PREV

MENU

IF3-1.EPS

2. Press the “Cal” softkey to bring up the next menu shown below:

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