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.

Pharmaceutical and Medical Aerosol Sizing

Testing Aerosol Outputs from Metered-Dose Inhalers and Nebulizers

Our PC-2AS/SK76 10-stage Quartz Crystal Microbalance (QCM) real-time cascade impactor system is configured for the pharmaceutical scientist and the inhalation therapy researcher to get aerosol size information rapidly.

This system is a ten-stage inertial impaction system with a built-in NASA-developed electronic QCM mass sensor in each stage which automatically determines or “weighs” in situ the amount of aerosols collected in a particular size range. Unlike a conventional cascade impactor, this system does not require manual weighing of impaction plates, or conducting chemical analysis on the samples collected, to determine the aerosol size distribution. It provides size distribution data automatically in a hard copy printout after a sample run. It allows the user to have the advantage of using a preferred inertial impaction - a directly mass-based - sizing technique without the disadvantage of labor-intensive post-sampling analysis to get sizing data. With this cascade impactor, it will take less than a minute or two to get a set of data.

The PC-2AS/SK76 covers a particle size range of 10 to 1.4 microns. Its 10-stage impactor operates at a low flow rate of 0.24 lpm to allow it to handle aerosols of relatively higher concentrations without dilution. A 12.5 lpm higher flow sample inlet is added to draw aerosols with high efficiency to the impactor inlet. An isokinetic flow divider is incorporated at the inlet to allow the QCM impactor to draw samples from the 12.5 lpm higher flow stream at a lower flow rate of 0.24 lpm without distorting the aerosol size profile. The instrument is supplied complete with pump and is ready for turnkey service.

Whether it is for testing outputs of metered-dose inhalers or for testing performances of continuous output nebulizers, this system has proven itself to be a reliable and accurate instrument over a number of years. Many of our customers have used this instrument in conjunction with a conventional purely mechanical cascade impactor. It provided the facility to get data rapidly while the conventional impactor is used from time to time to cross check results through weighing or chemical analysis of the samples. Even for customers who have laser-based instruments, this system has been found to be a valuable adjunct to cross check data obtained from two systems utilizing different technologies.