MA640 Datasheet, PDF (9/12 Pages) Extech Instruments Corporation. – 600Amp AC/DC True RMS Clamp Meter

Data Hold
To freeze the LCD reading, press the HOLD button. While data hold is active, the HOLD
icon appears on the LCD. Press the HOLD button again to return to normal operation.
MAX/MIN
1. Press the MAX/MIN button to activate the MAX/MIN recording mode. The display icon
"MAX" will appear. The meter will begins recording and displaying the maximum
value measured.
2. Press the MAX/MIN button and “MIN” will appear. The meter will display the minimum
value measured during the recording session.
3. To exit MAX/MIN mode press and hold the MAX/MIN button for 2 seconds.
RANGE
In the Voltage, Resistance, Frequency or Temperature function the meter automatically
selects the best range for the measurements being made. For measurement situations
requiring that a range be manually selected, perform the following:
1. Press the RANGE button. The “AUTO” display icon will turn off.
2. Press the RANGE key to step through the available ranges. Observe the decimal
point and units displayed until the preferred range is located.
3. To exit the Manual Ranging mode and return to Autoranging, press and hold the
RANGE key for 2 seconds.
LCD Backlight
The LCD is equipped with backlighting for easier viewing, especially in dimly lit areas.
Press and hold the HOLD/ button for 2 seconds to turn the backlight on. The backlight
will automatically turn off after 5 seconds.
Automatic Power OFF
In order to conserve battery life, the meter will automatically turn off after approximately 15
minutes of operation. The meter will beep shortly before the meter shuts off. If a button is
pressed, the APO timer will reset. If the meter is allowed to shut off, turn the function
switch to the OFF position and then to the function again to restart.
Low battery indication
When the
icon appears in the display, the battery should be replaced. Refer to the
battery replacement procedure in the maintenance section.
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MA640 V2.1 07/08