Fluke Calibration 5730A, Руководство оператора, Страница: 200 / 260

5730A
Operators Manual
7-8
Establish Traceability
Traceability to national standards is established as follows:
•
Except for the internal ac/dc transfer standard, the internal check standards are
directly calibrated by traceable external standards every time the Calibrator is
calibrated.
•
The internal ac/dc transfer standard is never adjusted, so its traceability is not
disturbed by calibration. Infrequent verification is done in the traditional way, by
comparing selected ac voltage outputs with an external dc voltage standard through
an external ac/dc transfer standard. Fluke Calibration recommends this to be done
every two years or as determined by the policy of your organization.
•
Infrequent independent verification is also done on stable parameters, such as
frequency flatness, determined more by circuit geometry and dielectric constants than
time.
Calibration Reports
The 5730A Calibrator stores two sets of calibration constants: the set currently in use and
the old set from the previous calibration. This gives the Calibrator the ability at any time
to produce a calibration report of the differences between the present settings and the
settings that were in effect before the last calibration. The report shows shifts in various
output values from before to after the most recent calibration for each range and function
in +/- ppm of range and in percentage of specification limit. The report can be saved to a
USB drive or retrieve it from a host computer through either the RS-232, USB device
port, Ethernet port, or IEEE-488 interface.
Range Adjustment
After calibration, further fine adjustments can be made to each range. Range adjustments
are optional and they are not necessary to meet total uncertainty specifications. However,
they can help to align the Calibrator closer to in-house standards.
Before range calibration is done, first do the Artifact Calibration as described later in this
chapter. This is to calibrate the ranges that will not be adjusted. It also performs an initial
adjustment for each range, and supplies flatness corrections for ac functions.
DC Zeros
DC Zeros is a quick, automatic process that corrects offset errors that increase with time
on several output ranges. If a 5725A Amplifier is attached, it also zeros the 11 A dc
range. This process takes approximately 2 ½ minutes (plus an additional 30 seconds for
the 5725A).
Run DC Zeros
To execute dc zeros, from the normal operation screen:
1. Touch Setup Menu to show the Setup Menu. See the “Setup Menu” section of
Chapter 4.
2. Touch the Calibration menu.