Differential vs Single ended

[john.stm]

I wanted to use DAQ card (ME-4680 measurement card with ME-Synapse + 78 pin D connector) .

I am having a technical question and the figure is attached for your reference.

I am having a sensor which has only one output (Not differential output) .

I wanted to connect it to a differential measurement. I am having AI0(+) and AI0(-). DAQ gnd and sensor power supply ground is also tied together.
I know that my Sensor output has to be connected to AI0(+).

My question is can i connect my sensor power supply -ve to my AI0(-)
View attachment Präsentation1.ppt

 

[crutschow]

Since the sensor ground is connected to the DAQ ground, then you can connect the minus differential input to the sensor ground also (if i understand your question correctly). But for lowest noise you want to connect the minus differential input as close to the sensor signal ground point as possible.

 

[john.stm]

Hi cruschow ,, thanks for ur tipp . i have my sensor atleast 3 m away from my daq ? will this be a problem ? can u tell me how the noise is lowered if i keep the distance between them very short...? thanks in advance

 

[crutschow]

For that distance you should likely used twisted-pair or shielded twisted-pair cable to minimize noise pickup. The amount of noise pickup depends upon how electrically noisy the area is, the sensor output impedance, and the length of the cable.