Problems with dasylab

[tronchita]

i need to calculate the output of a quarter bridge using strain gage,i can just read the output values directly from the bridge using a voltimeter but with dasylab i get a lot of values and i can see no changes when im bending the beam(the SG is sticked on it).the amplifier is configured with 5v input and a gain of 100,how can i configure dasylab to see the same results as with a voltimeter(0v when there is no bending and ?v when i aply a force)
Thanks

[CJ_Butler__DASYLab_Pro]

We need much more information than you have provided:

DASYLab Version
Driver installed
Actual Data Acquisition card
Analog Input Range setting for the channel

Regards,

--cj

[tronchita]

I need to calculate the output of a quarter bridge using strain gage,i can just read the output values directly from the bridge using a voltimeter but with dasylab i get a lot of values and i can see no changes when im bending the beam(the SG is sticked on it).the amplifier is configured with 5v input and a gain of 100,how can i configure dasylab to see the same results as with a voltimeter(0v when there is no bending and ?v when i aply a force)
Im using the 8.0 version of dasylab and the measeurement box is from BEDO type SAE 16288/05 with a card type SAK 34-500-102-5-L04 with 4 chanels for the strain gage bridge and configured as follows:
Input signal:+/-5mV,+/-50mV,+/-0,5V
Output signal:+/-5V
Starin gage:Full
Input resistance:1M Ohm
Bandwith:1000 Hz
Excitation volt:5V
Gain:100

The DAQ pc card is from IOtech type Daq/216B 16bit,the A/D specification:
Resolution:16 bit
Conversion time:8 micro sec.
Sampel & hold amplifier:
Aquisition time:2 micro sec max
Aperture delay:40 ns

I hope that is can help you a bit.
Best regards.

[CJ_Butler__DASYLab_Pro]

No... I'm sorry... I still need to have you confirm the DRIVER that DASYLab has loaded. It's sounding to me like you have the Demo driver loaded, and that the hardware is not configured correctly.

Can you upload or email the "Help -> Report" information from your software?

--cj

[tronchita]

I thank you for your help,Im making my thesis in a company and we are using the full version of dasylab,so there is no problem with the software,but i´ve found the problem.it was a really stupid mistake.our measurement box it´s configured with 3 board card that use an other student for his thesis(every card with 4 channels) and now we´ve just instaled a new card also with 4 channels for my thesis prupose(measurement with Strain gage) the problem was in the numbre of channel that i used,i used always the channel number(0),and i must used the channel number(12),because there is 16 channels in total from(0,1,....15) so the first channel of my board card is the channel(12).
So I made my pretest with a SG sticked in a beam(claculate the elongation when its bending) and the results were really closer to the theoritical calculation,i was really happy,but the real target of my thesis is to calculate the strain in the stabiliser of a car,and it´s with a biaxial SG applying a torsional force.
the pretest was static but with the stabiliser we will have a dynamic test using cylinders to give the torsional force to the stabiliser,so then i have to take care about the frequency and a lots of others factors.
So i hope that i can solve the problems that maybe occurs during my test next weeks,i thank you once again and if i have some other questions i will contact you.

Best regards

[tronchita]

Im calculating the elongation in a stabiliser of a car in a dynamic system using strain gage as half-bridge,with a force of torsion provided by two hidrocylinder.
The bonding of the strain gage it seems good but i want to know if the values that i get are good or not,because i ´ve made other tests and i got alwayas accurate values to the theoretical or expected values,but the others tests were static,and now i get values that they differ from the theoretical about 20(Micrometer).
the strain gage is a two grid gage 6/120XY41-3-3M in 45° and 120 Ohm resistance.
Is that normal?because the stabiliser is held with two bearings,and maybe there is a losses of the force across the stabiliser.
Best regards.
Nizar Hmamda