hallo everyone ..i need your guidance i have to make a test rig to measure strain for which i have to install strain gauges on to the beam and make a circuit to measure the strain ..Here i need help in 3 areas
How do i build a Hbridge amplifier circuit to measure output voltage
AMong the different Arduino microcontroller which arduino (Arduino Uno, Mega2560, Duemilanove, Mega, or Diecimila) would be appropriate choice for the strain measurement
3 Will the usage of strain gauges with leadwire be an Ideal choice for installation
i am attaching an image of expected installation of strain gauge .
this is the first time and
I dont have experience with strain gauges , circuit and microcontrollers ..
Please help me out if you have any idea about the same
Thank you
A load cell contains many times two opposite placed strain gauges. With weight, one is compressed and the other is stretched. That makes it easier to use in a wheatstone bridge and it also eliminates most noise from outside.
thank you so much Mr peter for the reply ... so i am expecting to use wheat stone half bridge circuit ,if possible could you provide an examplary image for the circuit connections with amplifier that u have mentioned (wiring connections along with microcontroller, strain gauge and amplifier)
And how to read strain value through microcontroller .Does it need to be done through programming
Try eBay for the HX711; comes on a breakout board for under $5. There are also a couple different Arduino libraries out there that you can use with it.
In the past, often the INA125 amplifier was used, and the analog output of that was read by an Arduino. But the Arduino is only 10-bits, that is not enough by far for a strain gauge or load cell.
But in the last years, often a seperate chip that includes a ADC (Analog to Digital converter) is more often used.
The HX711 as Chagrin wrote is such a chip. This is a project with it: Weight_Sensor_Module_V1-DFRobot
You can find projects at http://hackaday.com/ Search for "strain gauge" or "load cell".
