I have been using Open Scale successfully on several load cells. I have 4 Mettler Toledo 250 pound load cells I want to use for an industrial conveyor scale. I have not been able to get any weight values out of these. I have wired all 4 together, wired in only 1 load cell, I have wired them through the Mettler Toledo combiner board. They have 5 wires. 4 are the standard colors and the 5th is yellow for the shield. The result is the same, no weights. I checked resistance on all 4 cells and they were the same at .290. I asked Mettler Toledo for a data sheet for these load cells since they don’t show up on their website. No response from them. Any help/guildence/suggestions would be appreciated.
Thanks
Model on the load cells, please.
Some might have amplifiers built in, others are digital, others yet have weird impedance. ‘Standard’ colors likely have as many exceptions as adherents.
The part number is 90346000A and the model number is 776. They are branded as Mettler-Toledo. Other information on the label- Accuracy Class III -MDL 0
-Dmax 5000 M -Vmin .043 -SAFE LOAD 375 -C-O-C NO. 97066
Thanks
Thanks.
Try this:
Exc+ Green
Exc- Black
Sig+ White
Sig- Red
The 776 load cells have a top and bottom so make sure that the hump is Down and secured so that the remaining beam can bend down. Apply 5 or 10 volts DC to Green & Black and measure for millivolts of output on White & Red when the load cell is loaded.
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Thanks for the help, that worked. The only thing I had to do is switch the Sig + with the Sig- to get positive numbers. It was a bad assumption on my part that load cell wire colors were a standard. Thanks for sharing your knowledge.
Cool, glad it’s working.
I got turned around myself and meant the hump should be UP for your application (several cells summed under a scale platform). The hump provides clearance for the cell to deflect when loaded which otherwise needs a spacer or other accommodation.