Martel Electronics 320 - Manual (Page 37)

at the lower left corner of the keypad area. The
negative terminal is common to volts and milliamps
measurements.
To measure current, press the V/mA Key, until
milliamps is displayed on the upper line of the LCD
display. If you have a Model 320 with 2 pressure
sensors, you must first ensure that volts/mA are
available by pressing the Port Select key.
There are 2 current ranges and the Model 320
autoranges between them. The ranges are 0-
20.000mA and 0-50.00mA. When the input current
exceeds approximately 22 mA, the Model 320 will
change to the 50mA scale. When the input current
falls below 21 mA, the Model 320 switches back to
the 20mA scale.
PRESSURE
The model 320 measures pressure at the 1/8” FNPT
port at the base of the unit. Units with 2 pressure
sensors or one differential sensor will have 2 ports.
The full scale pressure for the individual port(s) is
shown at the base of the keypad, directly above the
pressure port(s).
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