Section 5: Basic Digital Multimeter (DMM) Operation
Series 3700 System Switch/Multimeter User's Manual
5-32
3700S-900-01 Rev. C / July 2008
Standard resistance measurements
CAUTION
Inputs: Do not apply more than 425V peak between INPUT HI
and LO, or instrument damage may occur.
CAUTION
Switching cards: Do not apply more than 300V DC or 300V
RMS (425V peak) for AC waveforms between any two pins, or
switching module damage may occur.
For example, if INPUT Channel 1 HI is 300VDC from Channel 1
LO, Channel 1 LO must be 0VDC from chassis ground.
Perform the following steps to measure resistance:
1. Press the
OPENALL
key to open all switching channels. Refer to DCV for
DMM function, range, and other settings.
2. Connect the resistance(s) to be measured. Refer to DCV for DMM
configuration assignments to channels and open close instructions. Refer to
the DCV section on triggering procedures.
3. To measure other switching channels, repeat steps 5 and 6.
4. When finished, press the
OPENALL
key to open all channels.
Offset-compensated ohms
The presence of thermal EMFs (V
EMF
) can adversely affect low-resistance
measurement accuracy. To overcome these unwanted offset voltages, you can
use offset-compensated ohms (OCOMP). Offset-compensated ohms
measurements can be performed on the 1 , 10 , 100 , 1k , and 10k ranges
for the 4 function. It cannot be done on the 2 function.
NOTE
The various instrument operations, including OCOMP, are performed
on the input signal in a sequential manner.
For a normal resistance measurement, the Series 3700 sources a current (I) and
measures the voltage (V). The resistance (R) is then calculated (R=V/I) and the
reading is displayed.
For offset-compensated ohms, two measurements are performed: one normal
resistance measurement, and one using the lowest current source setting.
