Hofmann PMH-2, Руководство пользователя

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This shows that mV can be traced over the entire 1000mV range or as
little as 100 mV. (See Fig.8)
Choosing setpoint control [SP.] fixes the 4mA to the programmed
setpoint. The signal current increases as the actual mV moves away from
the setpoint. In UP mode the signal current increases as the mV falls below
the setpoint. In dn mode the signal current increases as the mV rises
above the setpoint. (See Fig.9)
The amount of current increase versus mV is governed by the pro-
grammed slope that can be selected from 50 to 500mV. ( Do not confuse
the term “slope here with the slope calibration of mV).
Example:
Mode is UP, setpoint is 650 m and mA slope is set at 200 mV.
Signal current output is 20mA as long as the mV is below 450 mV, starts
to decrease as the mV moves to 950 at which point signal current is 4mA.
Calibrating 4mA and 20mA with a multimeter.
A real current calibration is carried out by connecting a multi meter
across the terminals (no termination resistor is required) to measure the
mA current.
The meter can also be connected in series in an already existing
installation. (See Fig.10)
Enter calibration [CAL] and ‘Rotate’ until the 4mA LED lights up. ‘PUSH’
to enter 4mA calibration. The display shows 4.00. Dial the measured mA
with ‘Rotate’. ‘SAVE’ and the actual current is corrected to 4.00mA. Move
FIG. 9 4-20mA Setpoint Signal current control.
PMH-2 Instruction manual PAGE 25