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Operating Instructions 2
MAKING MEASUREMENTS
2-24. MAKING MEASUREMENTS
2-25. Input Overload Protection Limits
WARNING
TO AVOID SHOCK HAZARD AND/OR INSTRUMENT DAMAGE,
DO NOTAPPLY INPUT POTENTIALS THAT EXCEED THE INPUT
OVERLOAD LIMITS SHOWN IN TABLE
The 8842A is protected against input overloads up to the limits shown in Table
FUNTION
Table
CONNECTORS | MAXIMUM INPUT |
|
|
VDC
MA DC
2 WIRE/4 WIRE kΩ
VAC
INPUT HI and LO:
2A INPUTand INPUT LO:
INPUT HI and LO:
SENSE HI and LO:
INPUT HI and LO:
1000 dc 2000mA
300V rms
300V rms
700V rms, 1000V peak, or 2 x 107
MA AC
All Funtions
2A INPUT and INPUT LO: | 2000 mA rms | |
Any terminal to earth: | 1000V dc or peak ac | |
|
|
2-26. Measuring Voltage and Resistance
To measure voltage or resistance, select the desired function and connect the test leads as shown in Figure
2-27. Measuring Current
To measure current, select the desired function and connect the test leads as follows:
1.Turn off power in the circuit to be measured (Figure
2.Break the circuit (preferably on the ground side to minimize the common mode voltage), and place the 8842A in series at that point.
3.Turn on power in the circuit, and read the display.
4.Turn off power in the circuit, and disconnect the 8842A.
2-28. Current Fuse Protection
The 2A input terminal is protected from overloads by a 2A, 250V fuse which is accessible from the front panel, and by an internal 3A, 600V fuse. If either fuse blows, the 8842A will respond as though the input were zero.
WARNING
TO AVOID ELECTRIC SHOCK, REMOVE THE TEST LEADS
BEFOREREPLACING THE FRONT PANEL FUSE.