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Automation, sensing and robotics • Re: Hand Grip Dynamometer (DIY)

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Re: Hand Grip Dynamometer (DIY)
by ame » Tue Jan 06, 2026 1:11 am
What have you tried so far? How do you know they are inaccurate?
I'm using a strain gauge load cell and I've written a calibration code that completes a zero offset calibration by reading a number of samples and taking the average, then does the same with a known weight.
The calibration factor is found with the following

known_weight = float(input("\nEnter the weight you placed (in grams): "))
avg_with_weight = sum(samples) / len(samples)

calibration_factor = (avg_with_weight - zero_offset) / known_weight

and it is then saved to a text file that I call and load in the grip strength file. The HX711 reads the samples and converts my values to newtons and kg.

raw = read_average(10)
weight_g = (raw - zero_offset) /calibration_factor
force_n = grams_to_newtons(weight_g)
force_kg = grams_to_kg(weight_g)

The values the code spits out is a mixed bag. Sometimes it's negative values, sometimes it's saying my grip strength is less than a kg. I haven't used a load cell or HX711 before so I am not too sure whats going on

Statistics: Posted by cmb0504 — Fri Jan 09, 2026 8:47 pm



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