Compressed Air Testing: Why and How to Test Industrial Air and Gas
August 07, 2018
When testing industrial compressed air for contaminants, the International Organization for Standardization (ISO) deems three types of contaminants vital for testing and removal: air, oil, and water. According to the ISO, “in addition to the above-mentioned contaminants of particles, water, and oil, ISO 8573-1:2010 also identifies gaseous and microbiological contaminants.”
What Is Compressed Air Testing?
Compressed air manufacturers must test for contaminants to ensure the best-quality products. Some of the contaminants that are present in compressed air include gases, microorganisms, oil, particles, and water. When these particles remain in the compressed air, they can make their way into the final product and contaminate it.
Compressed air testing is simply a standardized test that can be used to analyze the quality of the air and detect any contaminants.
The international standardized test for compressed air contaminants is ISO 8573. It checks for the three most common contaminants: oil, particles, and water. The formatting for this test is ISO 8573-1:2010 [P:W:O].
What Is the ISO 8573 Compressed Air Quality Standard?
The ISO 8573 compressed air quality standard, the nationally recognized air quality standard test, analyzes and samples the compressed air. This system creates simplified standards for the air quality in industrial air and gas. Using the same system across the board allows manufacturers, labs, and compressed air suppliers to be upheld to the same standards.
It is recognized in Germany, India, the United States and the United Kingdom. Using this standardized method is both efficient and cost-effective.
What Is the Compressed Air Testing Procedure?
Compressed air quality testing procedures usually involve three different testing procedures to demonstrate air purity. The following three tests are frequently used in fuel gas conditioning. The first two kits are more widely necessary than the kit for microbial and gases.
Air Compressor Testing Procedure for Water
Testing methods for water include hygrometers, chilled mirror, and electrical sensors. Other methods include chemical reaction (by way of detector tubes) and spectroscopy. Hygrometers are also often attached to compressor systems to determine the compressed air dew point of the system at any given time.
Compressed Air Testing Guidelines for Oils
There are four types of oils that need to be tested in compressed air purity testing: oil, oil aerosol, organic solvent and wall flow. Oil testing can be one of the more complex procedures, as testing can take up to 10 hours to complete. Oils are also tested at low levels, so the testing containers must have airtight fittings for complete accuracy.
Testing for Particles
Particles are tested based on size. The size ranges include 0.0 to 0.5 microns, 0.5 to 1.0 micron, and 1.0 to 5.0 microns. These are categorized by ISO 8573-1:2010 (the 2010 update to ISO 8473). Particle testing is performed by a laser particle counter (LPC). The LPC is an efficient indicator of particles because it can test class 1 and class 2 particles. The entire test takes around 10 minutes.
The particles can also be tested by way of a filtering system that collects the particles and analyzes the level of particles in the compressed air. However, this system is not always as efficient since the filters must then be analyzed by microscope, whereas the particle readouts on the LPC can simply be downloaded to a USB drive for analysis.