Fluke 5500A, Руководство по обслуживанию

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5500A
Service Manual
6-78
The Calibrator Mainframe first prompts the user to calibrate the DC Voltage function. If
another function is to be calibrated, alternately press the OPTIONS and NEXT
SECTION blue softkeys until the desired function is reached.
6-101. Calibration and Verification of Square Wave Functions
The AC Voltage and Edge functions have square wave voltages that need to be
calibrated and verified. The HP3458A digital multimeter can be programmed from either
the front panel or over the remote interface to make these measurements.
6-102. Overview of HP3458A Operation
The Hewlett-Packard 3458A digital multimeter is setup as a digitizer to measure the
peak-to-peak value of the signal. It is set to DCV, using various analog-to-digital
integration times and triggering commands to measure the topline and baseline of the
square wave signal.
6-103. Setup for Square Wave Measurements
By controlling the HP 3458A’s integration and sample time, it can be used to make
accurate, repeatable measurements of both the topline and baseline of the square wave
signals up to 10 kHz.
The HP 3458A is triggered by a change in input level. The trigger level is set to 1% of
the DCV range, with ac coupling of the trigger signal. The delay after the trigger event is
also changed for the of AC Voltage Square Wave and Edge functions. See Table 6-48
and Figure 6-19.
Table 6-48. AC Square Wave Voltage and Edge Settings for the HP3458A
Voltage
HP 3458A Settings
Input Frequency NPLC DELAY (topline) DELAY (baseline)
10 Hz 1 .02 s .07 s
100 Hz .1 .002 s .007 s
1 kHz .01 .0002 s .0007 s
5 kHz .002 .00004 s .00014 s
10 kHz .001 .00002 s .00007 s
Note
For this application, if making measurements of a signal > 1 kHz, the HP
3458A has been known to have .05% to .1% peaking in the 100 mV range.
For these signals, lock the HP 3458A to the 1 V range.