Fluke 5720A service manual The Calibration Process, Establishing Traceability

5700A/5720A Series II Calibrator

Service Manual

TRADITIONAL CALIBRATOR CALIBRATION

CALIBRATION CYCLE

COST $

TIME

5700A/5720A SERIES II CALIBRATION

CALIBRATION CYCLE

COST $

TIME

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Figure 1-1. Time and Costs: Calibrator Calibration

1-17. The Calibration Process

Calibration requires only three external standards: 10V, 1Ω, and 10 kΩ. Environmentally-controlled internal check standards provide the primary reference points. A stored table of calibration constants defines additional reference points for controlling the output. Traceable calibration and adjustment to the specified level of performance is accomplished in a semi-automated process that revises this table.

When you finish calibration, but before you save the new constants, the calibrator presents you with the proposed adjustments as +/- ppm of range and percentage change in specification for each range and function. You can print a list of changes through the serial (RS-232C) port, or send them to a computer through either the serial port or the IEEE-488 port. Also on completion of calibration, the calibrator displays the largest proposed change.

Calibration can be completed as far as deriving and printing the proposed adjustments without changing the setting of the rear panel CALIBRATION switch; however, the switch must be set to ENABLE to store the changes in nonvolatile memory and make them effective. The switch is recessed to allow the metrologist to cover it with a calibration sticker to guarantee calibrator integrity.

1-18. Establishing Traceability

Traceability to national standards is established as follows:

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