Unstable voltage sampling of usb-6210

[Yao725]

I have a USB-6210 and I use it to get lithium battery voltage. As shown in the picture，it performs well in the beginning of sampling. But after a while, the fluctuation of the sampling voltage will suddenly increase.

I want know what happened and how to solve this problem, Could anyone help me? By the way, I have checked the sampling wires connection and changed the sampling channel, but none of these worked. 

Thanks,

Yao.

[Gevor]

HI, have you tried measuring anything else besides the battery? 
Does the deviation continue to rise or it stays in range as in attached picture?  

[Kevin_Price]

Keep in mind that the fluctuation is only increasing by +/- 0.002 V, which is pretty small for many purposes.

You might get some insight by looking at that "noise" in the frequency domain, perhaps it isn't random.

-Kevin P