CEMB USA T7-LVDT_120 User Manual
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TRANSDUCER POSITIONING
Refer to drawing Nr. 9934
1)
Fasten transducer T7 at the anchoring point without locking the shaft diameter 6.0
mm to the valve opening control mechanism; bear in mind that the shaft is provided
with preloading which sends the linear transducer to end of stroke in one of the
two directions; to return the stroke to mid position, turn the shaft clockwise.
2)
Reconnect transducer T7 to converter AD1 and connect the latter to the measuring
instrument using the flying plug connector provided as standard.
3)
Connect a voltmeter in parallel to the signal input in the measuring instrument,
downstream to adapter module AD1 (voltmeter connected across pins A and D of the
converter connector (or else across the corresponding terminals of the transducer
signal input of the measuring instrument)
4)
With the measuring instrument operating, search for exact coincidence between the
mid measurement of the transducer and the mid measurement of the valve control
mechanism to which the shaft should be connected by proceeding as follows:
-
Set the valve opening control mechanism in position corresponding to 50% of its
opening angle (max. possible for the transducer = 120°) noting its direction of
opening
-
turn the shaft until reading 0 Vdc on the voltmeter checking that the reading is
decreased when rotating in direction opposite to the direction of opening of the
valve control mechanism, while it is increased when the wheel rotates in the
opening direction
-
rigidly fasten the transducer shaft to the valve control mechanism being careful not
to knock the transducer and making sure that the rotation of the shaft is only
stressed by the torsion imposed by the rotational motion.
5)
If possible, check whether the minimum and maximum mechanical opening of the valve
control mechanism corresponds with the scale start and full scale readings of the
measuring channel of the instrument in question
6)
If this is not possible, carry out operation 6 and proceed to re-calibration of
measuring channel by following the instructions given in the instruction manual
regarding the instrument supplied.