Metek EX1200A SERIES, Руководство пользователя

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Appendix A 147
EX1200A DMM C
ALIBRATION
/V
ERIFICATION
I
NTRODUCTION
Verification is the process by which the measurements of the EX1200A DMM are compared to
reference standards to determine variances between the values measured by the DMM and the
values outputted by the standard. After the completion of verification, a report can be saved that
shows the measured and expected values for the points measured. Using the EX1200A DMM’s
verification functionality, the user can generate “before” and “after” data for trending purposes.
Calibration is the process by which the DMM is adjusted and modified through changing
calibration constants (i.e. offset and gain) to more tightly correlate the values it measures with the
values outputted by the reference standard. Calibration generates a list of calibration constants
which can be saved and viewed upon completion, but does not generate a report with the expected
and measured values. VTI recommends that the EX1200A DMM have factory calibration
performed annually to ensure that the instrument maintains its accuracy and precision. The
following procedure describes the resources and steps necessary to perform verification and
factory calibration.
R
EQUIRED
R
ESOURCES
Equipment Needed
LAN/GPIB gateway (Agilent E5810A)
8.5 digit DMM (Agilent 3458A)
Function generator (Agilent 33220A or the Agilent 33120A)
Calibrator (Fluke 5700A Series
II )
Calibrator amplifier (Fluke 5725A, used to measure the 3 A limit)
EX1200A DMM calibration/verification cable (VTI P/N: 52-0807-000)
Ethernet switch
Ethernet cables (straight cables)
GPIB cables
PC with Windows XP/Vista, 512 MB RAM, and a Pentium 1 GHz (or faster)
Software Needed
A web browser (Internet Explorer, Firefox, etc.) with Java support
Java Runtime Environment
The latest version of EX1200A firmware, available on the VTI Instruments web site.
Bonjour (optional: used to discover the EX1200A, requires use of IE Version 6 or higher)
Agilent Connection Expert (optional: used for instrument discovery if Bonjour is not used)
NOTE Before performing calibration, ensure that the EX1200A mainframe has the most current firmware
version available. It can be downloaded from
www.vtiinstruments.com . Refer to the Upgrade
discussion in Section 7 for assistance more information on updating firmware.
S
ETTING
U
P THE
I
NSTRUMENTS
1) Connect a GPIB cable from the LAN/GPIB gateway to the DMM.
Connect a GPIB cable from the LAN/GPIB gateway to the function generator.
Connect a GPIB cable from the LAN/GPIB gateway to the calibrator.
Connect an Ethernet cable from the PC’s LAN port to the Ethernet switch.
Connect an Ethernet cable from the Ethernet Switch to the LAN/GPIB gateway.
Connect Fluke 5700A Multifunction Calibrator with 5725A amplifier.
Power up all the instruments.