Using 2 load cells on a single scale (wiring and mounting)

Projects General Guidance
1

Hi,

I'm building a project that requires monitoring weight. I was planning on using 2 load cells(10 kg) + HX711 + arduino mega(as I will be connecting a lot of other sensors to it).

How do I use 2 load cells(4 wires each) on the same scale as I need 20kg of capacity and one load cell only has 10kg. Do I simply connect each load cell to its own amplifier and then add both value in the software or there are better ways to do that by wiring them up somehow?

Also maybe someone has a good ideas on how to mount 2 of them on a single scale? Any example projects or drawings? Wasn't able to find anything online that use 2 of them.

Novice over here so any tips and tricks would be very helpful and appreciated

Load cells I'm using:

Load Cell Amplifier:

Design I'm currently thinking about:

2

Also does anybody knows if the accuracy of such load cells degrade over time as I will be using this system for almost a year?

Thanks

3

If a quality load cell and used within their specifications (mounting, excitation voltage and load, especially) I would expect them to last for years. I, in my job, had load cells that had over 20 years of use.

4

groundFungus:
If a quality load cell and used within their specifications (mounting, excitation voltage and load, especially) I would expect them to last for years. I, in my job, had load cells that had over 20 years of use.

Great to know! I bough them from trusted local store so I believe they should be of pretty good quality.

Maybe you have more information on using 2 of them on a single base and best way to mount them?

5

scales with multiple four wire load cells - Google Search turns up this thread, which shows how to wire four load cells as one.

There are likely to be similar discussion for two load cells.

6

I have seen that thread, but I was not successful getting any measurements using ideas from it.

To be honest this is my first electronics project ever, so even simple things are pretty complicated for me. I need this device I'm making for science experiments at my university.