Is it important to consider the cable resistance when using strain gauges?

The cable resistance can be a significant factor in the accuracy of the overall measurement. It is very important indeed to consider this point.

Prosig software allows the cable resistance to be entered by the user. Once this resistance has been entered, any calculations or calibrations carried out will be based on the known values of the bridge resistors as well as the resistances of all of the cables.

In most cases this will be negligible except if long cables are used.

When should I use the ground connection on my P8000 data acquisition system?

The ground connection should be used if an issue has been observed in measured data, such as significant electricity supply (50Hz or 60Hz) distortion or significant noise.

It must be attached it to a very good earth point (like a steel pipe or foundation)

It should be noted that sometimes connecting the ground cable to earth can actually make matters worse. It depends on the situation.

Should I use an IEPE accelerometer, a charge accelerometer or a bridge based accelerometer?

What are the advantages/disadvantages of a charge mode accelerometer, an IEPE accelerometer and a bridge based accelerometer?

An IEPE accelerometer will have a high pass filter at about 5Hz. The charge type will, by it’s nature have what is effectively a high pass filter at about 0.1Hz. Therefore neither type will show DC levels. The charge type will usually have a lower frequency bandwidth than the IEPE type. Charge accelerometers can be used at higher temperatures however. Contine reading