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[TechNoir]

I'm newbie tech and am having problems troubleshooting (calibrating) a load cell. Can some one advise me on how to do so?

[daqmaster]

Load cells are fairly easy to troubleshoot because they act like any resistive sensor. Since they use an exciter voltage like a Wheatstone bridge, you should start your troubleshooting procedure by measuring the supply voltage. If the exciter voltage is low or absent, you must take care of this problem before continuing the troubleshooting process.

The second part of the troubleshooting process involves applying a physical load to the cell. Look up the specifications for the load cell and apply a load that weighs approximately 50% of the maximum allowable load. The 50% load should cause the load cell to produce approximately 50% of its rated output. For example, if the load cell specification indicates the output is 3mV/volt of excitation, and the exciter voltage is 10 volts, the maximum load is 200 lbs, and the test weight is 100 lbs. The following formula will indicate load cell output voltage at the test weight should be approximately 15 mV when a 100 lbs test weight is applied:

V out max = nominal output (mV/V) x excitation voltage
V out max = 3mV/V X 10 Vdc
Output voltage (at test weight) = (test weight / max weight) x V out max
Output voltage (at test weight) = (100 lbs / 200 lbs) x 30mV = 15mV