MP Filtri PML2, User Manual

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Introduction 5
1 Introduction
The PML² Contamination Analyser is designed to measure and quantify the num-
bers of solid contaminants in Hydraulic, Lubrication and Transmission applica-
tions. The PML² is designed to be an accurate, instrument suitable for permanently
installed applications utilising mineral oil as the operating fluid.
The instrument uses the light extinction principle whereby 2 laser light systems
shine through the fluid and land on photodiodes. When a particle passes through
the beam it reduces the amount of light received by the diode, and from this change
in condition, the size of the particle can be deduced.
The PML²-W has the additional feature to allow the measurement of % saturation
of water in oil (RH), and temperature (°C).
Temperature measurement provides a reference temperature for the Relative Hu-
midity reading (RH).
Due to the temperature gradient existing between the system tapping point and the
RH/temperature module, the temperature reading can be 5°C to 10°C less than the
actual system temperature, depending on operating conditions.
Hydraulic and Lubricating Systems consist of sets of continuously moving metal
parts, which use hydraulic fluid as the power medium. Hydraulic fluid is also used
to create a lubrication film to keep the precision parts separated and it is also used
as a cooling medium. The very nature of a hydraulic system is that it produces
solid particulate contaminants and these are ever present in all hydraulic systems.
There is a revised standard ISO cleanliness code ISO 4406: 1999 which classifies
the numbers of particles that can be tolerated within the system and it is these levels
of contaminants that the particle counter is designed to measure.
1
1
ISO Cleanliness Code – The international standard for reporting solid contaminants is ISO4406: 1999,
this standard has been revised to incorporate the change to ISO Medium Test Dust as the calibration
standard.