Installation Guide - Position Transducers
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The maximum input voltage must not cause the potentiometer to exceed its power rating. See each product's data
sheet (
) for power ratings. The maximum voltage may be calculated with the formula of V = square root (P x
R) where V is voltage, P is power, and R is the potentiometer resistance. Also, never apply power to the wiper
(identified as "2", "OUTPUT", "SIGNAL", or "S+" on the potentiometer or schematic) or short the wiper to the power
source. If the possibility for this exists, consider putting a current-limiting resistor in series with the wiper. The
Potentiometer-Based Position Transducer Voltage Divider and Power Calculator located at
information on power, voltage, and current limits.
6. Mounting
Mount the position transducer using the mounting holes shown on
each product's
. Ensure that when the displacement
cable is attached to the point of contact, it exits the position
transducer aligned with the cable exit hole. You may also mount
the product using epoxy, magnets, suction cups, double-backed
tape, clamps, or a custom mounting bracket. The
provides hex wrenches for adjusting the mounting
hardware located on the position transducer. See Figure 5.
Figure 5
7. Wiring
Using the wiring scheme on each product's
, connect the electrical terminals or cable leads to your
electrical connector, data acquisition system, or power supply (as appropriate). Ensure power does not get applied
to incorrect wires such as the wiper.
8. Special Notes For Analog-Output Position Transducers Using Cam Lock-
Mounted Potentiometers
For single-turn potentiometer models mounted with cam locks, the zero voltage point may be adjusted by loosening the
3 cam lock screws securing the potentiometer to the position transducer housing. The potentiometer can be rotated to
the desired position and the cam lock screws re-tightened. Multi-turn potentiometers cannot be adjusted.
Single-turn potentiometer models mounted with cam locks do not contain physical stops and additional cable is
provided on the threaded drum. Therefore, these models will rotate beyond 360°. After the 360° point, the electrical
signal will show a discontinuity as the potentiometer wiper goes over the open segment of the potentiometer element.
Be aware of this as you plan your position measurement application.
Do not turn the terminals on the potentiometers. Doing this will break the electrical connections within the
potentiometers and render them non-functional and non-repairable.
9. Zero and Span Controls (Voltage Conditioner, 4-20 mA, Bridge Outputs)
Position transducers with voltage conditioner, 4-20 mA, or bridge outputs have zero and span controls. These zero
and span controls allow for range calibration. One of the primary purposes for range calibration is to adjust the
output signal to represent a voltage or current range that maximizes resolution when undergoing analog-to-
digital conversion. To access the zero and span trim potentiometers, remove the two 4-40 screws labeled "Z" and
"S". Rotate the span trim potentiometer clockwise to increase the total range of the signal. Rotate the zero
trim potentiometer clockwise to increase the zero point of the signal.
The benefit of zero and span controls is illustrated in the following example. A data acquisition system might accept
a signal range of ±5 V. To maximize the resolution, it is possible to adjust the transducer's output so it is exactly ±5
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