strain gage exp using SCXI-1000

[mekdeng]

Hello All,

I am working on strain measurement experiment using strain gages. I am using SCXI-1000 signal conditioner, SCXI-1317 connector block. I have a plate supported on 4 sleeves. 2 strain gages are attached to each sleeve. When I connect 4 strain gages one from each sleeve  to the connector block and apply a force of 200lbs on the plate and do a test run in labview, the strain values I am getting are way off. Here the details of inputs

Lead Resistance: 0
Gage Resistance: 120
Gage factor: 2
Strain range max = 1M
      min = -1M
V(initial) : 0
V(exe) : 5V
V(exe) Source: External
Srian gage config: Quarter Bridge 1

The Strain values I expected to be around 50 microstrain.
The vlaues I am getting are 180, 520, 370 microsrtain, fluctuating +/- 50 microstrain to the above vlaues. The fourth strain gage is reading -75microstrain and is stable. I tried changing V(exe) but nothing really chaged in readings except the fourth strain gage but it always was a negative valve.

I could not figure what am I doing wrong. If anyone in the group has any experience with this please help me out.

Thank you

Mekdeng

[devchander]

Hi Mekdeng,

Good to see that u posted this query here.

could you please tell me the result after this discussion in the below given link?

http://forums.ni.com/ni/board/message?board.id=170&message.id=154450

regards

Dev

[mekdeng]

I configured the SCXI-1000 chassis, SCXI-1521 module and SCXI-1317 connector block in the MAX. But now I have a different problem, I am unable to calibrate my strain gages in MAX. I think the reason is I am using 120ohm strain gages and SCXI-1521 works with only 350ohm resistors. Probably I have get a new set of 350ohm strain gages and work with them. I wondering there is any work around for this problem with out changing my strain gages or the module?...

Thank you