14
Enabling limits
— Press SHIFT and then ON/OFF to dis-
play the beeper status. Use the
▲
and
▼
keys to change
the beeper status (NEVER, OUTSIDE, or INSIDE) and
press ENTER to enable limits. Pressing SHIFT and then
ON/OFF a second time disables limit operations.
Reading hold
With this feature, an audible beep is sounded when a
valid, settled reading is acquired. A valid reading is
determined by the specified window and count.
1. Press SHIFT and then HOLD. Select a window per-
centage and enter a count.
2. Apply the test probes to the signal and wait for the
beeper to sound to indicate a valid reading.
3. Remove the hold condition by lifting the probes.
Pressing SHIFT and then HOLD a second time disables
hold.
Dry circuit testing
This feature lets you make low resistance measurements
on contact devices such as switches and relay contacts.
Its purpose is to determine whether oxidation has
increased the resistance of the contacts. Test voltage is
limited to 20mV to keep the oxidation from being punc-
tured. Punctured oxidation would invalidate the test.
While in 4-wire ohms (
Ω
4), select dry circuit testing by
pressing SHIFT and then DRYCKT.
Offset compensation
Offset compensation is used to cancel the effect of volt-
age potential (i.e., thermal offsets) across the device
under test during resistance measurements. In general,
the instrument performs voltage measurements at two
different test current levels and then calculates resis-
tance as follows:
R =
∆
V /
∆
I
