Step 5 for Compressed Air Analysis: Measuring Compressed Air Quality according to ISO 8573 Part 1
Compressed air is an expensive, but also indispensable medium in industrial, automated production. It is therefore all the more important for users to always keep an eye on the quality of their compressed air system.
ISO 8573 is an internationally recognized standard that defines the most important impurities in compressed air. The implementation of this standard supports the precise testing of the most important impurities in compressed air particles, water, gas, microbiological and oil contamination.
Solid Contaminants and Particle Classes
Contaminants in solid form originates from many different sources, likely dust particles from the surrounding atmosphere drawn by compressor air intake, or by abrasion and corrosion in the compressed air pipelines. Their size can range from large granular to even submicron in scale, and possibly be colony forming units.
In general, Industrial and pneumatic tools are equipped with general-purpose air filter with a particle size rating of 5 μm (class 6) and 40 μm (class 7), while not absolute particle removal ratings, it is at least 95% effective (described in ISO 12500-3) and is satisfactory in keeping pressure and power losses to a minimum.
Liquid Contaminants, Humidity, Liquid water and Oil classes
The main liquid contaminants within a compressed air system are water, lubricant/coolant from compressor, and other contaminants that can be drawn into compressor air intake from the surrounding atmosphere. The concentration of the contaminants are dependent on temperature and pressure, and can range from liquid wall flow to submicron aerosols due to condensation of their vapors. It is important to minimize these types of contaminants as they promote corrosion, which will generate further contaminants down the distribution system. Likewise, an unchecked oil contamination will further increase risks of product contamination, overloading of filters, odor problems and even fire hazards.
Gaseous Contaminants
Similarly, contaminants in gaseous form is generally comprised of water vapor and contaminant, lubricant/coolant vapor. The concentration is dependent on both temperature and pressure, and can be drawn into the distribution system from the surrounding atmosphere into the compressor air intake. With a increase in pressure, or a reduction in temperature, gaseous contaminants can condense into liquid form.
While there are no contaminants classes for gaseous contaminants, ISO 8573-6 details test methods for gaseous contaminants content for both on-site and laboratory (off-site) sampling.
Off-site laboratory analysis is commonly associated with time delays and only provides the customer with an average snapshot over the measured period and is not always practical. Thus, more and more compressed air users are inching towards continuous monitoring to reliably control the efficiency of the compressed air system and effectively rectify issues that surface.
CS Instruments offers customized solutions for stationary and mobile monitoring. An alarm can be used to signal that maintenance work is required on the compressed air treatment system (dryer and filter) so that oil, water and particles do not enter the compressed air network. This reduced prevents the risk of contamination of end products and increases the process reliability and lifespan of pneumatic components.
CS Instrument Compressed Air Quality Solutions