Control Buttons - Extech Instruments MA440 User Manual

Control Buttons
Mode button: Short presses to step through the mode options for the selected
measurement function
HOLD and Backlight button (MA443/MA445): Short press to freeze/unfreeze reading.
Long press to turn backlight ON or OFF. Note that the backlight button is in the upper
right side of the meter for the MA440 (see Side Button description below)
HOLD button (MA440): Short press to freeze/unfreeze reading
(MA443/MA445 only) Short press to enter the maximum measurement mode (LCD
displays 'MAX'); press again to enter the minimum measurement mode ('MIN' is
displayed). Long press to exit this mode. MAX/MIN is available on the AC
Voltage/Current, Resistance, and Temperature MA445 functions only
(MA445) Short press to store the displayed reading as a reference value. Subsequent
measurements will be displayed as 'measurement minus reference value'. This
feature applies to AC/DC voltage, AC current, resistance, and temperature modes
only. Short press to exit. For DC current measurement mode, short press to zero the
display; the LCD will show the delta symbol. Short press to exit this mode.
(MA440/MA443) Short press to store the displayed reading as a reference value.
Subsequent measurements will be displayed as 'measurement minus reference
value'. This feature applies to AC/DC voltage, AC current, resistance, and temperature
modes only. Short press to exit.
(MA440 only) Short press to toggle frequency (Hz) and duty cycle (%) measurements
for the Voltage and Hz switch positions. The MA443 and MA445 have a duty cycle
mode accessible using the MODE button when the function dial is set to Hz%.
SIDE BUTTON The button located on the upper right side of the meter is either for the LCD
backlight (MA440: short press ON/OFF) or work light (MA443/MA445: Long
press ON and short press OFF).
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