25
Magtrol Load Monitoring Units LMU 212 & 217
Chapter 3 – Calibration
w
arning
:
t
h e
l oa d
m o n i to r i n g
u n i t
w i l l
o n ly
b e
o p e r at i o na l
w h e n
t h e
m i C r o
-
s w i t C h
s w a 1 0
i s
o n .
3.1.5 A
djustment
of
the
detection
thresholds
The following conditions are required to adjust the detection thresholds:
• No load must be applied to the strain gauge transducer.
• The micro-switch SWB9 (see
figure 3–3
) must be On to activate the test signal.
• To adjust the detection thresholds U
level1
and U
level2
place the micro-switches SWC3 and
SWC4 (see
figure 3–2
) on On.
1 2 3
4 5 6
7 8
OFF
ON
9 10
SWC
micro-switches
Fig. 3–2 Location of the micro-switches SWC3 and SWC4 on the load monitoring unit board
Calculate the threshold voltages in relation to the voltage output U
O/P
:
U
O/P level
=
10 V × F
level
F
nominal
3.1.5.1
Adjustment of the detection threshold U
level1
1. Connect a digital millivoltmeter between terminals 15 (U
O/P
) and 9 (0 V) of the load
monitoring unit.
2. Adjust the potentiometer P9 to obtain a reading of U
O/P level1
with an accuracy of ±20 mV.
Figure 3–1
indicates where the potentiometers P1 to P10 are located.
3. Turn the potentiometer P3 until the LED on REL1 goes on.
Figure 3–3
indicates the location
of this LED.
4. Turn the potentiometer P3 slowly until the LED of REL1 goes off: the detection level will
then be switched off.
Содержание LMU 212
Страница 48: ...41 Appendix B CE Conformity Declaration...
