M-142 Multifunction Calibrator
MEATEST, s.r.o.
22
User Manual v54
Generation of calibrated current
The multifunction calibrator provides calibrated DC and AC current. Output terminals for voltage ranges are
labeled “ +I “ and “ -I “ at the front panel. The terminals can carry high current and are the only terminals to
which the calibrated object can be connected. Depending on the setting of the calibrator, current up to 20 A
ef
can
be driven by the terminals.
DC current range is 0 to 30 A
AC current range is 1
A to 30 A
When 25/50-turn coil (option 140-50) is used, AC current range is 50
A to 1000 A.
Control in the current mode
•
Press “I” button on the calibrator and then select AC or DC mode by pressing “DC-AC” button. The display
shows the following data:
*
main data of set current
*
relative deviation
*
uncertainty of output current
*
frequency (when AC current is generated)
*
total value of output current when non-zero absolute or relative deviation is set
*
time after which the output terminals will be disconnected when the output current over 10 A is
selected.
•
Set the desired value of voltage, including polarity when necessary, frequency and relative deviation. The
signal is yet not connected to the output terminals. The information section of the display shows the
symbol which informs about the disconnection of output terminals.
•
Connect the load or short the output terminals lI, -I.
•
Press OUTPUT button.
•
Red LED is lit above the OUTPUT terminals to signal the connection of the signal to the output terminals;
the information section of the display shows the symbol
.
•
Calibrated current corresponding to set parameters is driven by the output terminals.
•
If COIL x 50 or COIL x 25 function is activated (see below - Setup functions menu), the optional 50-turn
coil must be connected to output terminals. The calibrator can be used to calibrate 25
A to 500 A or 50
A
to 1000 A ammeters. The calibrator generates AC and DC current within the range up to 20 A with current
coil.
CAUTION
If GND terminal is connected to Lo, -I terminals, it is prohibited to connect
external load to GND / Hi or GND / +I terminals. Such connection can
damage the calibrator.