Keithley 2182, User Manual, Page: 93 / 339

Ratio and Delta 5-3
Step 1 Connect voltages to be measured to the Model 2182.
Details on connecting the Model 2182 to the voltages to be measured are provided in
Section 2 (see “ Connections ”).
WARNING A hazardous voltage condition exists at or above 42V peak. To prevent
electric shock that could result in injury or death, NEVER make or break
connections while hazardous voltage is present.
CAUTION Exceeding the following limits may cause instrument damage not covered
by the warranty:
• Channel 1 HI and LO terminals have a maximum measurement
capability of 120V peak. These inputs are protected to 150V peak to any
terminal or 350V peak to chassis.
• Channel 2 HI and LO terminals have a maximum measurement
capability of 12V peak to Channel 1 LO. Channel 2 HI is protected to
150V peak to any terminal. Channel 2 LO is protected to 70V peak to
Channel 1 LO. Both inputs are protected to 350V peak to chassis.
Step 2 Configure Channel 1 and Channel 2 for voltage measurements.
Configure each channel (DCV1 and DCV2) for the desired voltage measurement. Unique
settings for each channel include Range, Filter, and Rel.
Step 3 Verify on-scale readings for DCV1 and DCV2.
Verify that DCV1 and DCV2 are displaying on-scale readings. If an “OVRFLW” message is
displayed for any channel, select a higher range until an on-scale reading is displayed (or press
AUTO to enable autoranging).
Step 4 Select the range control channel.
If you want the manual range keys to control Channel 1 ranges, select (press) DCV1 just
before going into Ratio. If you want the manual range keys to control Channel 2 ranges, select
DCV2 just before going into Ratio. For more information, see “
Ranging considerations ” for
Ratio.
NOTE After Ratio is enabled (next step), pressing the AUTO range key will either enable
autorange for both channels or disable autorange for both channels.
Step 5 Enable Ratio.
To enable Ratio, press the V1/V2 key. The “CH1 / CH2” message will be displayed briefly.
While in Ratio, the “RA” message is displayed, and both the “CH1” and “CH2” annunciators
are on.
NOTE If an overflow condition (OVRFLW) occurs, the range that overflowed will format the
display.
Step 6 Take Ratio readings from display.