# Homework Help: How to connect strain gauge in the form of wheatstone bridge

1. Mar 7, 2013

### syedshaul

HAI I am SYED , i am doing my project using strain gauges.

Problem description: I have 4 strain gauges bonded to an octagonal ring. The strain gauge i am using is METAL FOIL TYPE , GF(gauge factor) -2 and 320ohm resistance. The strain gauge has two terminals ,my question is
(1) Can any one of the two terminals can be taken as positive and other as negative or is there any convention that the specified terminal should be taken as positive or negative...?

(2) I need help in connecting these 4 strain gauges in the form of Wheatstone bridge... ?

2. Mar 7, 2013

### sophiecentaur

What do you know about bridges in general? What produces 'balance' and 'imbalance?

3. Mar 9, 2013

### syedshaul

What do you know about bridges in general? What produces 'balance' and

when all the 4 arms in a Wheatstone bridge has same voltage in my case Millivolt produced by strain gauge the output voltage is zero then it is called balanced bridge and when one arm has high voltage than other arms then there is a output voltage this is called unbalanced bridge.

4. Mar 9, 2013

### sophiecentaur

OK, so maximum imbalance is when diagonally opposite pair of resistors increase and the other diagonal resistors decrease. Fit one pair to the front and one pair to the back of your flexing beam for maximum unbalanced volts.
Could you draw a diagram of that for me, to show you've got the idea?