Effect of residual flux on a strain gage.

Can you find what’s wrong with the high-temperature sensor in this video?
Let’s examine – How to deal with a “Resistance” to change? 🤔
As the old saying goes: “Flux is your friend while you’re soldering and then basically is your enemy once you’re done!” 💔
👉 Always ensure no flux gets on the grid of a strain gage, as the resistance shift will be accelerated.

[cristian-scd]

Hi, I'm willing to make a DIY device to measure force in real time. So a strain gauge solution is a best for this application. I've made my studies on strain gauge and tested different Wheatstone bridge connections and all works fine. But the difficult part ( ... and not having a starting point for testing ) is the dimensions of the mechanical part ... so here the questin:
Can you please help me with an estimate of required section dimensions of a 2mm thickness Aluminum part? So if I would need to measure a max 50N (~ 5kg ) of force, what would be the d x h section of the Aluminum part ( asuming h is thinckness and d is the section length)?
Thanks

[swedentorgerud]

If there is flux left on the strain gage, would that explain why I measure 350 ohm at the terminals, but when supplied with a 10 V excitation the signal to my DAQ is showing erratic measurements ±50 microstrain?