case studies

California Measurements instruments have been used for diverse applications in laboratories and at unique onsite locations all over the world. Our samplers are portable and rugged with an excellent track record of reliability for use in the field. Learn more about specific case studies and how results were achieved.

Air Cleaner and Filter Efficiencies

Our model PC-2H 10-stage Quartz Crystal Microbalance (QCM) real-time cascade impactor is a proven instrument for the testing of air cleaner and filter efficiencies in multiple application conditions.

Whether it is for testing the efficiency of air cleaners in a nuclear submarine or for finding out how efficient an air cleaning system is in a factory, engineers have relied on our PC-2H 2 lpm flow 10-stage QCM real-time cascade impactor to get the data they want, rapidly and on site. This instrument utilizes well-established inertial impaction principles to separate airborne particulates by size and covers a wide size range of 10 to 0.05 microns in ten size fractions. In addition, it incorporates NASA-developed state of the art QCM mass sensors in each of the impactor stages to determine the amount (mass) of particles collected in each size range, thus giving it real-time data reporting capability. The instrument automatically provides particle mass concentration data and size distribution histogram in a printout within seconds after each measurement. By getting a ratio of the size distribution data before and after the air sample passes through a cleaner, the efficiency of cleaning or particle penetration characteristics of an air cleaner can be readily determined.

The instrument is supplied complete with a pump and all the accessories required for turnkey operation in the field or in the laboratory.

It is easily transportable to the field and remote locations in two subassemblies in rugged enclosures, each weighing less than 25 pounds. Once set up in a factory building, for example, the instrument can be used to take a reading at one location for a few minutes and moved to other parts of the factory to make measurements quickly, getting multiple mass concentration and size distribution data at each location. Moreover, this instrument has the unique feature of collecting samples on a small substrate, for each size fraction, which can be retained and brought back to the laboratory to have them analyzed in a scanning electron microscope to determine their morphology and elemental composition, or to subject them to sensitive chemical analysis such as through GC/MS to determine their chemical make-up.

With this instrument, the engineer gets the full story on the efficiency of air cleaners and filtration systems. In addition, whenever needed, information on the nature and physical make-up of the particles can be gained through post-sampling analysis of the samples collected by the instrument. For almost 20 years the U.S. Navy and its contractors have used this instrument to get air quality data in nuclear submarines and surface ships; for buying new generation air filtration systems for ships, the Navy specified the use of this instrument to test their efficiencies by their suppliers. Adhesive-backed label manufacturers have used this instrument to assess the efficiency of mist suppressors installed to reduce the emission of fine respirable toxic liquid adhesive droplets emitted from high speed roller applicators.