Bently Nevada 19045, Installation Manual

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Section 2 - INSTALLATION
9
ADJUSTMENT
Adjustment requires measuring the LVDT output with the linkage set at the zero-
expansion point. Perform all adjustments as accurately as possible. The user may
construct a gaging tool, if desired, to aid in accurately adjusting the LVDT core
position during calibration. Table 2-1 lists recommended equipment for
adjustment. If LVDT power (-24 Vdc) is available from the instrument, the DC
Power Supply is not necessary.
LVDT linkage adjustment is performed in the following manner.
a. Disconnect the linkage at the machine case attaching point.
b. Supply the specified transducer power to the LVDT from the BNC instrument
or, if necessary, from the DC Power Supply. Check the voltage at the + and -
PWR terminals at the terminal block.
c. Connect the DMM to SIG and COM at the terminal block.
d. Manually adjust core position until the DMM displays 0.00 Vdc.
e. Move the LVDT core as follows:
If full scale expansion is toward-LVDT, move core away from the LVDT
exactly half the meter range of the indicator.
If full scale is away-from-LVDT, move core toward the LVDT exactly half the
meter range of the indicator.
The core is positioned for correct output signal at zero expansion of the
machine case. Mark or secure the core at this position.
f. Adjust the linkage carefully (with LVDT core at the zero-expansion position
set in step e) until the machine end of linkage is located at the zero-
expansion position of the attaching point on the machine case. Secure the
linkage adjustments.
g. Check the meter at the instrument to assure that linkage movement
produces the proper upscale/downscale meter response.
h. Connect the linkage to the machine case.