LCM

A 2-minute contamination test procedure:

A portable particle counter designed to be used in the field

icountLCM20 is a proven answer to fluid system contamination monitoring offering a 2-minute test procedure. Multi-standard ISO and NAS cleanliness reporting, data entry, data graphing, and integral printing are all standards on this world-proven contamination monitor.

Automatic Particle Counters (APC’s), have been widely used for many years in condition monitoring of hydraulic fluids. However, it is only recently that APC’s have become flexible enough to enable the instruments to be taken out of the laboratory and used online in order to obtain the most credible form of results.

Unusually, the move from fixed laboratory use, to portable field use has not been at the expense of accuracy or user flexibility but has actually enabled the instruments to be used over a wider range of applications and situations.

The most common monitoring technique used in APC’s is that of light obscuration or light blockage. Here, a focused light source is projected through a moving column of oil, (in which the contaminants being measured are contained), causing an image of the contaminant to be projected onto a photodiode cell, (changing light intensity to an electrical output).

The electrical output of the photodiode cell will vary in accordance with the size of the particles contained in the column of oil; the larger the particle, the bigger the change in the photodiode electrical output.

Online APC’s must be able to test the oil sample at whatever cleanliness it is delivered to the machine. Parker, therefore, had to develop technology to ensure the online APC was able to test a sample without the conventional laboratory technique which requires dilution - a practice that would have been simply impossible with a portable unit.

By careful design and window sizing, gravimetric levels as high as 310mg of dirt per liter, (equivalent to up to 4 million particles >6 microns per 100 ml), can be achieved without making the instrument susceptible to counter saturation.

This high saturation point online APC’s, whilst losing none of the accuracies of their laboratory counterparts, enable particle counting to be carried out quickly and accurately.

icountLCM20 makes the difference in the industry
Fully accredited to BS EN 60825:1992 and IEC 60825-1 (safety of laser products) Standards, accredited to USA Standards, and achieving full ISO certification. icountLaserCM offers users advanced laser technology, a fast, dynamic, and online 2-minute system test cycle. An icountLaserCM Aggressive Fluids model is also available, suitable for monitoring corrosive fluids such as phosphate ester-based lubricants used in commercial aviation.

MTD calibration
icountLaserCM MTD Calibration variants are certified via a primary ISO 11171 calibrated automatic particle counter. All MTD Laser CM20’s achieve ISO 4406:1999 criteria, via ISO 11943.

Understanding MTD
ACFTD (Air Cleaner Fine Test Dust) was formatted in the 1960’s, but is no longer being produced. The obsolescence of this dust has led to the adoption of a new dust MTD.

MTD (Medium Test Dust) having a particle size distribution close to ACFTD was selected as a replacement. However, MTD produced results
somewhat different to ACFTD, so the NIST (National Institute of Standards & Technology) undertook a project to certify the particle size distribution of ISO MTD.

The result was particle sizes below 10μm were greater than previously measured.