i just observe that i remove strain gauge from circuit and connect all 4 resistors in bridge , same value i am getting 0.040 , all 4 resistors and strain gauge has 120 ohm valueBaluncore said:It is probably working. Zero may wander a bit.
If accuracy is quoted as 1% balance error, then 0.04 V = 4 volt drive.
Load the beam and bridge normally, test it.
Does the beam and strain gauge provide a change of output voltage when loaded?Micheal_Leo said:, same value i am getting 0.040 ,
This can occur due to several reasons. One common cause is the presence of residual stress in the material of the cantilever beam, which can be due to the manufacturing process or previous loading conditions. Additionally, improper installation or calibration of the strain gauge might also result in a preload reading.
To zero out the initial reading, you need to recalibrate your strain gauge. This typically involves adjusting the zero balance of the strain gauge amplifier or the data acquisition system to negate any initial voltage. Make sure the beam and gauge are free from any external stresses or forces during this recalibration process.
The significance of the initial voltage reading depends on the expected range of strain and corresponding voltage output when the beam is under load. If the expected changes are much larger than 0.040V, this initial reading might be negligible. However, for high precision measurements, even small voltages like this can be significant and should be accounted for in your data analysis.
Yes, it's possible that the initial voltage reading is due to a fault in the strain gauge or its installation. Common issues include incorrect gauge placement, poor surface preparation of the beam, or faulty wiring connections. It's advisable to inspect the installation and, if necessary, reinstall the gauge or replace it if a defect is suspected.
Temperature changes can affect the resistance of the strain gauge material and hence the voltage output. Thermal expansion or contraction of the beam or the gauge itself can also lead to changes in strain readings. It is important to consider these factors, especially if the strain gauge is used in environments with fluctuating temperatures. Using temperature compensation techniques or materials can help mitigate these effects.