The ability of the DI-245 and DI-2008 to reject common mode voltage is unmatched in the $75 per channel price range.
To demonstrate the ability of the DI-245, where DI-2008 shares the same front-end configuration, to reject common mode (error) voltage, we connected K-type thermocouples to channels 1 and 2. With the thermocouple on channel 2 grounded, we then connected line voltage directly to the thermocouple on channel 1. This allowed us to demonstrate not only the common mode rejection, but also the channel-to-channel crosstalk rejection of the DI-245.
As the following video illustrates, the results were impressive, to say the least!
Additional Reading:
How to Eliminate Noise in Data Logging and Data Acquisition Measurements Introducing the DI-245 Thermocouple and Voltage Data Acquisition System