Using the Features (cont'd)
• dBm-Ω: The reference impedance is displayed for 1 second after selecting the dBm function.
Momentarily press dBm-Ω to change the reference impedance. Refer to the "Specifications" section
for the available values.
Note: This is an AC voltage measurement calculated according to the formula
dBm = 20 x log (measured voltage / reference voltage
The reference voltage is the voltage that causes 1 mW of power to be dissipated in the selected
reference impedance.
-T
: Press momentarily to select the desired temperature display: T
• T
1
2
• 500000: Press and hold to toggle between 50,000 counts fast mode and the 500,000 counts high
resolution mode for DC voltage measurements.
• Intelligent Automatic Power Off (APO): To extend battery life, the meter shuts itself off after
approximately 17 minutes of inactivity. Inactivity occurs when buttons are not pressed or the selector
is not turned. The meter will not enter APO when there are significant readings of over 10% of the
range or non-OL readings for resistance and continuity. To restore power, press SELECT, RANGE, ∆,
or HOLD or turn the selector to OFF and back on again. To disable this feature, press SELECT while
turning the meter on.
• Disabling the Beeper: Hold down the RANGE button while turning the meter on to temporarily
disable the beeper feature. Turn the selector to OFF and then back on to enable the beeper.
• Hz: Frequency can be measured in most voltage and current settings of the selector. Press SELECT
until "Hz" appears in the primary or secondary display, as desired. The sensitivity of the Line Level
Frequency function varies with measurement range. Refer to "Specifications." Auto-ranging mea-
surements usually set the best trigger level. If the frequency reading becomes unstable or is blank,
press the RANGE button to select another trigger level.
• %4-20mA: This calculated value is one of three available options for the secondary display when
measuring DC milliamps. It is useful for 4-20 mA industrial process control loop applications. A
reading of 4 mA on the primary display gives a 0% reading on the secondary display, 12 mA gives
50%, 20 mA gives 100%, etc.
DM-860A
T2
T2
, T
, T
, or T
-T
1
2
1
1
2
.
9