Online Particle Counter for Long-Term Fluid Condition Monitoring

PAMAS (Germany) develops, manufactures and distributes Automatic Particle Counters for fluid contamination control. The PAMAS product range includes measuring instruments for long-term condition monitoring of liquids like hydraulic or lubricating oil and for contamination analysis of particulate matter in water, pharmaceutical suspensions and many other fluids. At the Motion, Drive and Automation (MDA) exhibition, taking place from April 8th to 12th 2013 within Hannover fair, PAMAS will present a new product development for fluid condition monitoring: The compact online particle counter PAMAS OLS50P has been developed to be installed in to almost every system and offers a variety of interfaces for both analogue and digital data transfer.

PAMAS manufactures Automatic Particle Counters for various applications. A distinctive feature in which to separate instruments for different applications is the measuring environment: Portable particle counters are designed for on-site field measurements; they can be used both for batch and online sampling. Laboratory particle counters are ideal instruments for batch sampling. A sample of the liquid is collected into bottles and then taken to the PAMAS laboratory instrument for analysis. Online sampling is not possible using laboratory particle counters. Online particle counters are designed for continuous condition monitoring of fluids. The sample liquid is drawn from the system via a bypass line and analysed directly online during operation. After measurement of the fluid, the sample is fed back into the system.

To monitor their system fluid, system operators often opt for online instruments as they have three advantages compared to batch sampling systems: Firstly, batch sampling devices only analyse a momentary condition of the particulate contamination, whereas online sampling instruments enable continuous condition monitoring and instantaneously give an alert in case of a change (e.g. when a pre-determined limit of contamination is exceeded). Secondly, batch sampling requires accurate sample preparation before measurement. If the sample is not taken and prepared properly according to a standardised method, particulate contaminants from the environment may easily enter into the sample liquid. Thus, the sample preparation method affects the results of laboratory measurements: depending on the procedure of sample preparation, these results may often vary. For online measurements, the sample is not filled manually into bottles, so cross contamination from outside the system is impossible. The third advantage of online measurement against batch sampling is cost. Online sampling runs automatically and unattended. Compared to laboratory measurements, human labour and manpower can be reduced to a minimum.

To fulfill the increasing demand for online fluid condition monitoring, PAMAS developed the new online particle counter PAMAS OLS50P. This new stationary instrument has been successfully implemented as a fixed installation unit located in several customer plants. All types of light extinction sensors of the PAMAS HCB-LD series can be integrated in the newly developed PAMAS OLS50P. If required, the sensor can be built of resistant material so that it can be used for the analysis of all types of liquids and critical fluids, from water down to strong acid.

The PAMAS OLS50P is equipped with a wear resistant ceramic piston pump. The pump provides a constant flow rate of 25 ml/min at a pressure range from 0 to 6 bar. With its eight different size channels, the particle counter PAMAS OLS50P counts particles in eight size classes. The instrument measures the particle sizes > 4 µm(c), > 6 µm(c), > 10 µm(c), > 14 µm(c), > 21 µm(c), > 25 µm(c), > 38 µm(c) and > 70 µm(c).

For data transfer, the user has the choice between digital and analogue interfaces. A RS485 data interface is part of the instrument’s standard equipment for digital data transfer. The optional analogue 4-20 mA channel transmits data to a PLC (Programmable Logic Controller). This interface function makes the PAMAS OLS50P an effective instrument for condition monitoring.

To report and analyse measuring results, PAMAS provides two different software tools: The online visualisation software PAMAS POV has been developed for the online visualisation of measuring results and for long-term trend monitoring and The component test software PAMAS PCT helps to monitor parts and roll off cleanliness.

With the aid of the software tools, measuring results are reported according to common cleanliness standards (e.g. ISO 4406 or SAE AS 4059). Furthermore, the measuring parameter can be set up individually and adapted to the specific application profile.