Noise on STG 4004

Hi~
Recently, I have bought STG 4004 for MEA stimulus. I put all the device in the shielding box and used NI data acquisition system to get voltage from the STG 4004. I found there was a noise about 10mV from the STG 4004 (the NI system's noise level was 10uV as tested). That means if we connect STG to MEA and don't give any stimulus, the device would send 10mV voltage value to the microelectrode. As your manual points out the output voltage resolution is 1mV, how could I send the voltage less than 10mV (noise level)? The STG's native noise level has not been listed out yet. I wonder if there was anyone who also met such problem and how to overcome. Thank you.

Sam

Dear Sam,

the STG's maximum output voltage is +-8000 mV.
That means you are in a range well below 1% of the maximum
output voltage.
So a noise level of 10mV can be considered at the first glance as
normal.

But you see a 10mV 50Hz noise as well.

So we took a completely shielded osci probe without any connection and
found a 50 Hz noise
level in the same range (20 mV).
For that reason I think to reduce the 50Hz noise level further is a
demanding task.


Best regards

Thomas