Making Sense of Load Cell Sense Connections

The voltage drop along the connecting cable of a four-wire connection system and its associated temperature coefficient of resistance may contribute significantly to the overall system error. This additional error can be eliminated by the use of the six-wire connection technique where the voltage is sensed locally to the load cell and maintained at a constant level by a remote sensing power supply that automatically compensates for cable resistance variations.

A six-wire cable system, in addition to excitation and signal connections also has + and - sense lines that are designed to be connected to the sense terminals of the indicator, to feed back the actual excitation voltage at the load cell location. The advantage of using this ‘active’ system is the possibility to cut (or extend) a six-wire load cell cable to any length; it is important to realise that a six-wire load cell will not perform within its stated calibration if the sense connections are not used.

In the case of load cells or force transducers that are supplied with a four-wire connection system, the cable is part of the temperature compensated system of the load cell and the load cell is calibrated and compensated with that cable attached.  In this case, never cut or extend the load cell cable, as the calibrated performance of the load cell will be compromised. If you have any load measurement or force transducer requirements please contact us.