Operation; Powering The Meter; Disable Auto Power Off; Display Backlight - Extech Instruments EX350 User Manual

4. Operation
CAUTION: Read and understand all of the Safety statements listed in the safety section
of this manual prior to use.
Powering the Meter
1. Turn the rotary function switch to any position to power the meter. Check the batteries if the
unit fails to power ON. Refer to the Maintenance section for battery and fuse replacements.
2. Turn the function switch to the OFF position to power OFF the meter.
3. The meter has an Auto Power OFF feature (APO) where the meter switches OFF after 15
minutes of inactivity. When APO is enabled, the APO icon
the meter is powered ON. To disable APO, refer to the next section.
Disable Auto Power OFF
The meter will auto power OFF after 15 minutes of inactivity. To defeat this feature, follow the
steps below.
1. With the meter OFF, press and hold the M (MODE) button and, while continuing to hold, turn
the rotary function switch to any position to power ON the meter.
2. The meter will beep 5 times.
3. Release the button.
4. APO will now be disabled until the next cycle of power.
Display Backlight
With the meter powered ON, press and hold the backlight button for two seconds to switch the
backlight ON or OFF. Note that excessive use of the backlight will shorten the battery life.
When the power supply voltage of the battery falls to 2.6V, the LCD backlight will be faint or
unusable; the measurement function can be used normally however.
Data Hold
To freeze the LCD meter reading, press the H (HOLD) button. While data hold is active, the H
display icon appears on the LCD. Press the H button to return to normal operation. The H icon will
switch OFF.
will show on the display when
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