National Instruments Corporation 780181-01 NI 9239 BNC, 4-Ch +/-10 V, 50 kS/s/Ch,24-Bit, Ch-Ch ISO AI Module
The NI 9239 is a 4-channel, 24-bit C Series analog input module for use in any NI CompactDAQ or CompactRIO chassis. The NI 9239 is similar to the NI 9229 in functionality except for the input range. You can find detailed specifications for the NI 9229 and NI 9239 in the same manual for comparison.
With channel-to-channel isolation, your entire system, including the device under test, is protected from harmful voltage spikes up to the isolation rating. In addition to safety, isolation eliminates measurement errors caused by ground loops because the front end of the module is floating.