# A very quick query about strain gauges

1. Jan 3, 2004

### \$id

I am doing a project on strain gauges. I have the thing set up in a half-wheatstone bridge. Using a pair of strain gauges im trying to measure the weight!!(attaching each one to a side of a ruler/cantilever and bending it by attaching weight to the end)

So heres a confusing bit. I no when the gauges are unstrained the reading on the bridge shud be ZERO(i.e bridge is balanced) I'm measuring the voltage difference across the bridge not current. The point is when i bend them i get a reading(which i shud)

Am i correct in assuming that the resistance difference across the bridge when i bend it. This will b recorded as a voltage change?
SO heres a question. If i bend it more the resistance difference should b greater so should i get a bigger reading (voltmeter) on the scales or not??

I no the explaination isnt a perfect . PLease bear with me.

2. Jan 4, 2004

### Integral

Staff Emeritus
What voltage are you measuring?

If I recall correctly a Wheatstone bridge relies on current measurements. If one arm is out of balance, a current will flow through the center, you then adjust the resistance in the arm opposite the load to zero the current.

You may want to check into a spell checker, while it is possible to figure out what you are trying to say, frequently I will simply go to the next message rather then attempt to figure out something as poorly written as your message.