Sampling your compressed air does not have to be a difficult process. Examine the type of gas, the needs of the product manufactured, the regulatory controls in place, and the potential hazard to the user (ISPE, 2011). Bringing together all of these considerations will allow you to effectively choose the best testing equipment. An accredited third party laboratory can equip you with simple sampling tools and then provide a compressed air analysis quickly and efficiently.
Particles: Depending on the purity class that your facility is trying to achieve, a few different methods are available when testing for particulates. In order to achieve Purity Classes 0, 1 or 2, a laser particle counter should be used. If Purity Classes 3-6 are required, then sample collection by filter will be sufficient.
Microorganisms: The best way to test for microorganisms in a compressed air system is with an impaction sampler such as the SAS Pinocchio Super II KX00. The sampler collects microorganisms on an agar plate and the contamination is then analyzed using total plate count and bacterial classification.
Water Vapor: Facilities can test for water vapor contamination using chemical reactor tubes. It is important to follow the manufacturer’s recommendations when testing with this media, but overall, it is a simple and inexpensive way to ensure your compressed air is free from moisture.
Oil Aerosol: As with particles, oil aerosol can be collected with a filter cassette membrane. It is important to ensure that oil aerosol does not collect and pool in the compressor system.
Oil Vapor: Similar to water vapor, oil vapor can be tested using a detector tube. Charcoal tubes are best for sampling for oil vapor.