Primary Navigation
Home > Publications Directory > Technical Bulletins > PQ Provides Low-Cost Alternative to Direct Read Ferrography
PQ Provides Low-Cost Alternative to Direct Read Ferrography
PQ, or particle quantifying, is becoming an increasingly popular method for measuring concentrations of large ferrous wear particles in used oil samples and, when supplemented by spectrographic oil analysis, such as ICP, PQ provides a low-cost alternative to direct read ferrography for many reasons.
Unlike DR, PQ does not require multi-phase dilution for accurate results. The expense of using chemicals and the hazards of handling them are eliminated. Less material interference reduces both sample preparation time and the probability of human error. Therefore, PQ not only has better repeatability - it makes trend analysis more reliable and costs less.
How PQ Works
PQ exposes samples to a magnetic field. Those containing ferrous metals cause a distortion in the field, which is represented as the PQ Index, an arbitrary unit of measurement that correlates well with DR ferro large. The PQ90 is designed to monitor trends. It does not provide a ratio of small to large particles as does DR. However, if the PQ Index is smaller than an FE ppm by ICP, it's unlikely that particles larger than 5 microns are present. If the PQ Index increases dramatically while the ICP's FE ppm remains consistent or goes down, larger ferrous particles are being generated and further testing or diagnostics would likely be recommended.
What PQ Can Do For You
PQ is a very inexpensive way to regularly screen samples for ferrous metals and provides adequate information for recommending further testing on those determined to be problems. By far, it is considerably more thorough and cost effective to do PQ on a regular basis and run analytical ferrographs on samples with potential problems than it is to run a DR on EVERY sample.
Print this Technical Bulletin (PDF - 138K)
Quick Links
Top
News
POLARIS Laboratories® Expands into Central America
POLARIS Laboratories® is again extending its global reach with a new laboratory in Guatemala City. The expansion supports the company's global strategy for continued growth and is indicative of the strength and potential of the Central American market.
POLARIS Laboratories® Makes Inc. 5000 List Third Year in a Row
For the third year in a row, POLARIS Laboratories® has been named to Inc. Magazine's List of 5000 Fastest Growing Privately-Held Companies in America.
Training
Nashville
Cooling Systems Maintenance
March 6, 2012Nashville
Oil Analysis
March 7-8, 2012Houston
Cooling Systems Maintenance
April 17, 2012
Tradeshows & Conferences
UMA Motorcoach Expo
Long Beach, CA
February 8-12, 2012PepsiCo Summit & Tradeshow
San Antonio, TX
February 13-16, 2012
Secondary Navigation
