We are taking a differential reading between an analog signal (AIN0) and machine ground (AIN1). If machine ground fluctuates it apparently affects the differential reading. Am I correct? If so, is there a way to filter the ground signal? Our set-up is written below. 0.001V differential reading is equal to 1 micron. We can see spikes of greater than 100 micron; i.e. 0.1V
We have one U6 Labjack integrated into each of our labatory instruments. A laser distance scanner analog output is connected to AIN0 and the laser scanner reference ground is connected to AIN1. We take a differential reading between ref ground AIN1 and the analog signal AIN0.
Labjack SGND is tied to the machine ground which is the facility ground via main power feed ground to the machine. 0VDC of the 24VDC supply that powers the distance scanner is connected also to machine ground.
AIN1 ref ground signal logging is attached. Any thoughts on this are appreciated.