A load cell is a force sensing module - a carefully designed metal structure, with small elements called strain gauges mounted in precise locations on the structure. Load cells are designed to measure a specific force, and ignore other forces being applied. The electrical signal output by the load cell is very small and requires specialized amplification. Fortunately, Phidget Bridge Interfaces will perform all the amplification and measurement of the electrical output, see the Compatible Products tab for details.

Load cells are designed to measure force in one direction. They will often measure force in other directions, but the sensor sensitivity will be different, since parts of the load cell operating under compression are now in tension, and vice versa.

This Single Point Load Cell is used in small jewelry scales and kitchen scales. It’s mounted by bolting down the end of the load cell where the wires are attached, and applying force on the other end in the direction of the arrow. Where the force is applied is not critical, as this load cell measures a shearing effect on the beam, not the bending of the beam. If you mount a small platform on the load cell, as would be done in a small scale, this load cell provides accurate readings regardless of the position of the load on the platform.

Connection

Load cells require a power source and produce a very small voltage differential when under strain. In order to read this signal, an amplifier or a board with a high-precision analog-to-digital converter is required. For more details and a list of Phidgets that will connect to this load cell, see the Compatible Products tab.

Warning

Make sure to calibrate your load cell before using it. You can find information on how to calibrate the cell in the Load Cell Primer. You should also have a look at the User Guide for the bridge interface board that you're using to read the load cells.