CHECKING
1) Terminal wiring: Check that all cables are correctly con-
nected according to the connection diagram.
2) Power input voltage: Check voltage across the terminal
7 – 8 with a multimeter.
3) Excitation input: Check the excitation amplitude across
the terminal 3 – 9 with an oscilloscope. It is normal if the
amplitude is 6 – 10 Vp-p (4 kHz).
4) Secondary voltage from LVDT: Check the voltage across
the terminal 10 – 11 with an oscilloscope.
5) Output: Check that the load resistance meets the de-
scribed specifications.
ADJUSTMENT PROCEDURE
This unit is calibrated at the factory to meet the ordered
specifications, therefore you usually do not need any cali-
bration.
For matching the signal to a receiving instrument or in case
of regular calibration, adjust the output as explained in the
following.
■
FRONT PANEL CONFIGURATIONS
Front Cover (open)
Excitation Adj.
Gain Adj.
Span Adj.
Zero Adj.
LCD Meter
■
HOW TO CALIBRATE THE OUTPUT SIGNAL
Use a signal source and measuring instruments of sufficient
accuracy level. Turn the power supply on and warm up for
more than 10 minutes.
1) Displace the core of the LVDT to the middle of its work-
ing range and confirm that output becomes 50 ±5%.
2) Displace the core of the LVDT to the 0% position of its
working range and adjust Gain so as to adjust output to
0%. If output moves toward 100% instead, the polarity
of the LVDT is reversed. Interchange connection of the
terminals 10 and 11 and readjust Gain in such a case.
3) Displace the core of the LVDT to the 100% position of its
working range and confirm that output becomes 100%. If
output deviates from 100%, adjust Span so as to adjust
output to 100%.
4) The excitation amplitude is factory-set to 8 Vp-p but can
be changed as needed. If changed, be sure to perform
steps 2) and 3) again as outputs at the 0% and 100% posi-
tions also change accordingly.
MAINTENANCE
Regular calibration procedure is explained below:
■
CALIBRATION
Warm up the unit for at least 10 minutes. Apply 0%, 25%,
50%, 75% and 100% input signal. Check that the output
signal for the respective input signal remains within accu-
racy described in the data sheet. When the output is out of
tolerance, recalibrate the unit according to the “ADJUST-
MENT PROCEDURE” explained earlier.
LIGHTNING SURGE PROTECTION
M-System offers a series of lightning surge protector for
protection against induced lightning surges. Please contact
M-System to choose appropriate models.
MLV
5-2-55, Minamitsumori, Nishinari-ku, Osaka 557-0063 JAPAN
Phone: +81(6)6659-8201 Fax: +81(6)6659-8510 E-mail: [email protected]
EM-1356 Rev.8 P. 3 / 3
