CEMB USA T5-LVDT_100-24 - Manual (Page 3)

3
TRANSDUCER POSITIONING
Refer to drawing Nr. 51351.
FOREWORD
The sensor part carries a removable cover at the top. After removing this cover, it is
possible to read the mechanical value of the displacement on a graduated scale.
The transducer tip is fitted with a protective cap to protect against damage during
transport. Hence such cap should be removed during assembly.
The tip is held firmly in contact with the movable part of an internal spring device
which also provides a preloading stroke of 5.0 mm of the tip.
OPERATIONS TO BE PERFORMED
Remove the protective cap from the tip and separate the sensor part from the adapter
part AD1.
1) Remove the protective cap from the mechanical pointer of the sensor.
1) Make sure that the movable part to be tested (turbine casing) is in zero or known
displacement position.
2) Drill the mounting holes for the two parts making up the transducer: for the sensor
part, bear in mind the preloading stroke, then provisionally fasten the sensor
checking that the mechanical pointer gives the zero position (or known position) of
the displacement with exact preloading.
3) Electrically connect the sensor part to the adapter part, then the latter to the T
instrument using the connectors supplied as standard and following the manual
operating instructions.
4) With the transducer connected and energized, and by means of a voltmeter connected
across pins A and D of the adapter connector (or else across the terminals
corresponding to the input of the measuring instrument transducer signal), search
for the exact coincidence between the mechanical measurement checked and prepared
in points 3 and 4 and the electrical reading corresponding to the displacement,
bearing in mind that a displacement of 0 mm corresponds to 0.0 Vdc, a displacement
of 50.0 mm corresponds to 5.0 Vdc, while 100.0 mm corresponds to 10.0 Vdc.
Make some small displacements of the sensor part until the electrical reading
corresponds to the actual readng on the graduated scale.
5) Then lock the two parts making up the transducer into position and proceed to pin
the sensor.
7) For all these operations the utmost care is recommended in order not to damage the
internal mechanisms; above all, avoid sudden releases and knocks on the movable rod
of the tip.