I am acquiring analog input from two pulse sensors (World Famous Electronics llc.) and getting a curious 5-6Hz noise. The attached files show the time series and associated spectrum. I have run a basic check on the LabJack U6 and everything seems fine. Reading the pulse sensors from an Arduino Uno using the developers' code, the output looks fine as well.
Has anybody come across something similar? Any suggestions as to where to check next would be appreciated.
File Attachment:
.png%3Fitok=PHGBxf6M "EEV Blog Reviews LabJack T7-Pro & Software Tools")
.jpg%3Fitok=B1YcuDFK)
.png%3Fitok=Ybt-OlgU "LabJack + JEDI One Can Create a Powerful Distributed DAQ Ecosystem")
5-6Hz noise can get picked up due to a wide variety of issues. Perhaps your sensors aren't properly grounded?