Prokit's Industries MT-3109 - Manual (Page 14)

MT-3109 AC/DC Digital Clamp Multimeter
13
3. Press the lever to open the transformer jaw.
4. Center the conductor within the transformer jaw, then release
the Meter slowly until the transformer jaw is completely closed,
Make sure the conductor to be tested is placed at the center of
the transformer jaw, otherwise it will cause deviation. The
Meter can only measure one conductor at a time, to measure
more than one conductor at a time will cause deviation.
Note
 Press RELA to subtracts a stored value from the present
measurement value and displays a result.
 When current measurement has been completed, disconnect
the connection between the conductor under test and the jaw,
and remove the conductor away from the transformer jaw of
the Meter.
Sleep Mode
To preserve battery life, the Meter automatically turns off if you
do not turn the rotary switch or press any button for around 15
minutes.
The Meter can be activated by turning the rotary switch or
pressing the button based on 'The Effectiveness of Functional
Buttons" on page 14. Press SELECT to activate the Meter will
disable the Sleep Mode feature.
The Meter beeps 5 times in about 1 minute before entering
Sleep Mode and it will have a 1 long beep just before entering
Sleep Mode.
To disable the Sleep Mode function, press and hold SELECT
button while turning on the Meter.