Using Manifolds with Aerosol Particle Counters
Particle counters used in manifold systems typically undercount the particles in the air due to the vacuum pumping system required to move air through the manifold. Solutions have previously been implemented to overcome this issue but none are automatic or accurate enough. Learn more about Particle Measuring Systems patented smart flow technology to automatically and accurately solve this problem.
The powerful vacuum of the manifold pump causes the particle concentration of the sample to be lower than the particle concentration of ambient cleanroom air. Unless the system compensates properly, this lower concentration results in a corresponding under- reporting – typically under-counting by 7 – 17%.
Previous manifold sampling systems have either ignored this error, or have used some compensation system.
Until now, none of these compensation techniques have produced truly accurate counts. In part, this is because most have been based upon increasing the sample velocity; this in turn has generated particle under-sizing errors, which also resulted in as much as 40% under-reporting in the first channel.
The Lasair III offers the only manifold system that corrects for both of these issues. Using data from the patented pressure-sensor system, the Lasair III calculates the pressure-corrected, equivalent ambient sample volumes, and then sends Facility Net the normalization factors required to produce accurate measurements
Interested in learning more? Complete the form on this page to receive a free copy of the Improved Particle Counting Accuracy in Manifold application note.
