Fluke 5820A, Service Manual

Page: 68 / 158

5820A
Service Manual
3-30
3-36. Edge Amplitude Verification
For the edge amplitude verification, connect the Calibrator Mainframe’s CHAN 1
connector to the HP 3458A input, using the cable supplied with the Calibrator
Mainframe, the external 50
Ω
termination, and the BNC(f) to double banana adapter.
(The 50
Ω
termination is closest to the HP 3458A input.)
1. For measurements of a 1 kHz signal, set the HP 3458A to DCV, NPLC = .01,
LEVEL 1, TRIG LEVEL, and the DELAY to .0002 for measuring the upper part of
the wave form (i.e. topline), and the DELAY to .0007 for measuring the lower part
of the wave form (i.e. baseline). For measurements of a 10 kHz signal, set the HP
3458A to DCV, NPLC = .001, LEVEL 1, TRIG LEVEL, and the DELAY to .00002
for measuring the topline, and the DELAY to .00007 for measuring the baseline.
2. Manually lock the HP 3458A to the range that gives the most resolution for the
baseline measurements. Use this same range for the corresponding baseline
measurements at each step. Note that in the EDGE function, the topline is very near
0 V, and the baseline is a negative voltage. See Table 3-14.
3. For each calibration step, take samples for at least two seconds, using the HP 3458A
MATH functions to enter the average or mean value.
4. The peak-to-peak value of the wave form is the difference between the topline and
baseline measurements, correcting for the load resistance error. To make this
correction, multiply the readings by (0.5 * (50 + Rload)/Rload), where Rload =
actual feedthrough termination resistance. Record each reading as indicated in Table
3-14.
Table 3-14. Edge Amplification Verification
Calibrator
Mainframe Edge
Output
HP 3458A
Range
Topline
Reading
Baseline
Reading
Peak-to-
Peak
Peak-to-
Peak x
Correction
Tolerance
(
±
V)
100 mV, 1 kHz 100 mV dc 0.0022
1.00V, 1 kHz 1 V dc 0.0202
5 mV, 10 kHz 100 mV dc 0.0003
10 mV, 10 kHz 100 mV dc 0.0004
25 mV, 10 kHz 100 mV dc 0.0007
50 mV, 10 kHz 100 mV dc 0.0012
100 mV, 10 kHz 1 V dc 0.0022
500 mV, 10 kHz 1 V dc 0.0102
1.00 V, 10 kHz 1 V dc 0.0202
2.5 V, 10 kHz 10 V dc 0.0502
3-37. Edge Frequency Verification
This procedure uses the following equipment:
•
PM 6680 Frequency Counter with an ovenized timebase (Option PM 9690 or PM
9691)
•
N to BNC cable supplied with the Scope Calibrator