Water contamination visual indication

[Cryogenica]

I am looking to incorporate a small and inexpensive visual indication into an existing product. The problem we have been having is that even though we require nitrogen on this instrument, customers occasionally connect CDA or (DWA- dirty wet air). We need to have the indication to be able to support the non-warranty claim. Piping size is 1/4" and I have about an inch of length to work with.
Thanks.

 

[quark]

This type of thing may be of help to you. It is actually used in refrigerant liquid lines.

http://www.carrierhvacparts.com/Mer...n=PROD&Product_Code=CAR6X723&Category_Code=FD

Regards,