How to adjust the Zero and Span of a UniMeasure JX-P420 Draw Wire Transducer

Shipping container stacker
8 July 2022

One useful feature of the UniMeasure series JX-P420 draw wire transducers is the user can adjust the Zero and Span.

The JX-P420 series ranges from 250mm to 2m draw length, with no price difference between them. 

UniMeasure JX-P420-10-N11-10S-N11 Draw Wire Transducer
UniMeasure JX-P420 Series Draw Wire Transducer


This is particularly useful if you need a replacement transducer quickly and we do not have the model with the required measurement length in stock. We can adjust a longer length unit to be used for shorter length measurements. 

It can also be used when you need to position the sensor in a more suitable location. For example, in a safer location away from moving parts, flying rocks or direct water spray. It allows you to set the zero mm measurement start point with the draw wire partially withdrawn. 

How to adjust the Zero and Span 

To adjust the zero and span, first remove the two Phillips head screws from the potentiometer access holes located on the end of the transducer.  

Visually locate the adjustment screws on each potentiometer. The screws are very small and will require a small blade type screwdriver with a blade width of 1.5mm (max) and blade thickness of 4mm (max) for the adjustment. 

Adjustment screws on UniMeasure JX-P420 draw wire transducer

Extend the wire rope of the transducer to the desired zero position (must be within 0% to 30% of range) and adjust the Zero potentiometer to give a 4mA output.  

Extend the wire rope to the desired maximum position (must be within 80% to 100% of range) and adjust the Span potentiometer for the maximum output current of 20mA. 

Since the zero and span controls are interactive, recheck the zero and span settings and adjust as necessary. 

When complete ensure that a sealing O-ring is on each of the two Phillips head screws. Thread each screw into each potentiometer access hole until the head of the screw bottoms against the raised shoulder. 

Do not over tighten the screw against the shoulder. 

If you are not confident in making these adjustments yourself, do not hesitate to contact ADM to speak to a member of our team about having the unit adjusted prior to shipping.