Load Cell Matching in Weigh Bridge


Thread Starter


Can i connect two different capacity loadcells, i.e. 4 no. of loadcells 25T Cap and 4 no. of loadcells 30T Cap of the same manufacturer in a Road weigh Bridge?

i am facing a problem that when i place 6000kgs weight on all loadcells one by one. the weight on 25t loadcell is 6000kgs and on 30T loadcells the it is 5000kgs.

Is there some solution?
The problem sounds more like one of a scaling issue (input amplifier gains not set correctly) and/or possibly calibration issues.

Have the load cells been independently calibrated? (You should have a calibration datasheet with multiple test points, measured values and max and min deviation with the calculated slope and offset for a best curve first order fit. You can calculate the amplifier gain from the slope value.)

Are you using the 5000 kg as a single point verification of the output of the load cells? (Do you perhaps also have the capacity to perform shunt resistor verifications? These would need to be on the calibration datasheet.)

What do the output of the load cells read with no weight on them?

What level of excitation is being used on each bridge? Are they are the same and are they correct? (Measure them.)
The application is probably a long weighbridge. Generally different capacity loadcells are not connected together unless each loadcell has a different power supply and display

It seems you are using a single indicator for all the loadcells. You are bound to get the observed differences as each loadcell will give 20or30 mv with 10 V supply which is the industry standard

Is it possible for you to seperate the two decks ( if it is a weighbridge ) with one deck having the 25 T cells and one deck having the 30 T cells. You will need two indicators each showing the weight on each deck, and then sum up these two indicators to get the total weight

If the above is not possible, then the only way that i know of is having digital loadcells, where each cell can be individually calibrated . However i have not tried such a system