How To Use Optional Probes And Shunts - Keithley 172A Instruction Manual

OPERATING INSTRUCTIONS
INSTRUCTION MANUAL
Digital Multimeter
Models 172A. 173A
3-11. HOW TO USE OPTIONAL PP9BFS AND SHUNTS.
a. Model 1600 High Voltage Probe. Set the Model 172A/l73A to DC volts and 30 volt
ra"gtZ. The input resistance on the 30 volt range is IO megohms so that no shunt resistor
is needed. The Model 1682 has a 1OOO:l division ratio. For maximum safety review the
instructions furnished with the Model 1600 probeabove 30kV, switch to the 300V range.
CAUTION
A
The alligator clip (ground) must be connected to the source low so that high volt-
age is not applied between low and ground. Severe damage to the instrument will
occur if the alligator clip is r!otconnected.
b. Model 1682 RF Probe. Set the Model 172A/l73A to DC volts and 30 volt range. The
Model 1682 has a IVdc output corresponding to 1 V rms input over the range 100 kHz to
TOO MHz.
IMPORTANT
For use on the 3 volt range the banana plug adapter (with IO megohm resistor)
should be used since the Model 172A/l73A
input resistance is >I000 megohms on the
3 volt and 0.3 volt ranges.
c.
Model 1685 Clamp-On AC Current Probe.
Set the Model 172A/l73A to AC volts and 0.3
volt range. The Model 1685 provides a 0.1 volt rms output corresponding to a I ampere
rms input.
Review the instructions furnished with the Model 1685 to achieve best pos-
sible accuracy.
d.
Model 1651 Current Shunt.
Set the Model l72A/l73A to AC or DC volts (as appropriate)
and 0.3 volt range.
Connect the voltage leads to the Model 172A/l73A input terminals.
Connect separate-leads (not furnished) between the source and the Model 1651 hex-head
bolts.
The Model 1651 shunt resistance is 0.001 ohm which produces a sensitivity of I
millivolt per ampere.
3-12