Inexpensive Load Cells

Why not make your own load cell? A thin walled cylinder with strain gauges mounted on all sides tells you all you need to know. You will, of course have to calibrate it to begin.

This requires loading it with known loads and checking the strain gauge readings.

Exactly!!

I've made my own load cells using the existing beams available. Very cheap as the foil strain gauges are only a few quid (£).

Just make sure you clean the substrate very carefully and using iso cyanate instant glue very carefully bond the strain gauge(s) to the beam...

make sure you buy the strain gauges which are matched for temperature expansion of the substrate material i.e. aluminium or steel etc...

I've always used two to give me a ½ bridge, one in tension one in compression.

John.

The scale I purchased had only a strain gauge on one side of the beam. I guess having strain gauges on both sides will increase the accuracy. Correct?

Strain guages on both sides will give double the output voltage...

In a dire emergency if one fails you can still operate with the other one!!

Many catalogue companies stock the basic ones for aluminium and steel, RS components, Digikey etc...

I was trying to avoid that but it may be the route we have to take to reduce the cost on the product. Would you know of a source for the strain gauges? I would also need a design guide for load cells. Thanks for your help.

It has been many years since I worked with load cells and strain gauges. I'm afraid I am not current. I suggest you Google 'strain gauge'. Or check with the Structural or Mechanical Engineering faculty at a university closest to you.

ba/ael and Electroman - Thanks for your comments. I am just going to have to dig a little deeper on this one.

Regards,