Fluke 5500A, Service Manual

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SC300 Option
Calibration and Verification of Square Wave Functions
6
6-81
Note
The Calibrator Mainframe will warn when the entered value is out of
bounds. If this warning occurs recheck the setup and carefully re-enter the
reading insuring proper multiplier (i.e., m, u, n, p). If the warning still
occurs, repair may be necessary.
5. Repeat step 4 until the Calibrator Mainframe display indicates that WAVEGEN
CAL is the next step. Press the OPTIONS, then STORE CONSTS blue softkeys to
store the new calibration constants.
6-106. Edge Amplitude Calibration
This procedure uses the following equipment:
•
Hewlett-Packard 3458A Digital Multimeter
•
BNC(f) to Double Banana adapter
•
BNC cable supplied with the SC300
•
50
Ω
feedthrough termination
Refer to Figure 6-19 for the proper setup connections. Press the OPTIONS and NEXT
SECTION blue softkeys until the display reads “Set up to measure fast edge
amplitude”. Then follow these steps to calibrate edge amplitude:
1. Connect the Calibrator Mainframe’s SCOPE connector to the HP 3458A input, using
the BNC cable and the BNC(f) to Double Banana.
2. 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).
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
0V, and the baseline is a negative voltage.
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. See “Setup for Square Wave
Measurements”, earlier in this section, for more details.
The “true amplitude” 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.
6-107. Leveled Sine Wave Amplitude Calibration
This procedure uses the following equipment:
•
5790A AC Measurement Standard
•
BNC(f) to Double Banana Plug Adapter
•
50
Ω
feedthrough termination
•
BNC cable supplied with the SC300
Refer to Figure 6-20 for the proper connections.
Press the OPTIONS and NEXT SECTION blue softkeys until the display reads “Set up
to measure leveled sine amplitude”. Then follow these steps to calibrate Leveled Sine
Wave amplitude: