Connection of strain gauge and interface it with DAQ card (usb-6008)

[erfan.khalilian69]

I have bought strain gauge but I do not know how is the connection ? I mean which one is output or.... here is the photo of strain gauge, I searched alot but I didn't get it .
this link gives me the information but still confusing how much must be the value of resistors in the circuit ? is it possible to don't use any resistor and connect the strain gauge to amplifier directly? then from output of op-amp I can give it to daq card.
I will apreciate any suggestion of information
plz help me thanks
how sensors work - strain gauge

 

[srizbf]

measure the resistance of the strain gauge or read from the data sheet.

put the same value in its upper arm(R2 in fig you referred)

R1 and R3 should be equal value , can be same as R2 are multiples of it.

connect the o/p (shown as voltmeter) to your daq.

 

[erfan.khalilian69]

ok then how much you suggest for resistor ?

 

[srizbf]

it is the value of your strain gauge with no load applied.

 

[erfan.khalilian69]

I dun know how much is the value of strain gauge , becoz there is only one strain gauge with no specification, thanks then

 

[srizbf]

if you have the strain gauge , then measure its resitance with a multimeter(digital)

 

[erfan.khalilian69]

Hi I meausred the resistance but it shows 0 ohm, but while I measure the voltage and I apply force with my finger it shows various number, anyhow do you know how much should be the power supply (excitation voltage) assume that I want use half bridge circuit (two strain) or full bridge circuit (4 strain gauge).
thanks for your help

 

[srizbf]

try with digital meter in 200ohms range.
measure the resistance,