PAMAS S50DP: The Particle Counter With Integrated Dilution System For Fluid Analysis

The PAMAS product range includes measuring instruments for long-term condition monitoring of liquids like hydraulic or lubricating oil or for contamination analysis of particulate matter in water, pharmaceutical suspensions and many other fluids.

The newly designed PAMAS S50DP has been specifically designed for fixed online measurement of dark fluids.
This online particle counter automatically dilutes dark sample fluids prior to measurement with its integrated dilution system , thus reducing the sample’s turbidity level. Fluid cleanliness (e.g. of oil, water or fuel) can be monitored through optical particle counting. An automatic particle counter detects and measures particulate contaminants in the fluid. 

 An optical particle counter (like all the Pamas particle counters) uses a laser light source which is either absorbed or reflected by the particles in a liquid. The calibrated particle sensor analysis the absorbtion of the light from the particles to produce results. The measuring result provides information on the number of particles per millilitre as well as the size of each single particle.
This technique has its limitations. For example: in the case of dark fluids, the sensor’s laser is not able to penetrate the liquid. To enable particle counting of dark fluids, the sample fluid’s absorption needs to be reduced before analysis.The optical particle counting technique is also difficult to use if the level of contamination is to high e.g. greatly exceed the sensor’s maximum particle concentration level (coincidence error) , or if the sample’s viscosity is too high for an accurate measurement. In such cases, sample dilution with solvents helps to achieve reliable measuring results. For offline measurements like batch and bottle sampling, the dilution agent can simply be added manually.

It is more of a challenge if liquids are analysed online as an online particle counter is directly integrated as a fixed installation into the system (e.g. hydraulic/lubricating oil system or fuel tank). The sample liquid is drawn from the system via a bypass line and analysed directly.

The PAMAS S50DP online particle counter features an automatic dilution system that adds a programmable amount of solvent online to the sample liquid. The system’s inner structural design ensures that the solvent and sample fluid are thoroughly mixed to produce accurate, repeatable measuring results.

The PAMAS S50DP online particle counter is well suited for the analysis of fuel containing free water: Without prior dilution, free water in fuel would lead to false measurements. The diluting agent increases water solubility in the sample, so the water drops are no longer detected. Another application example is highly contaminated liquids. Without prior dilution, the coincidence error of such sample fluids would be too high due to the high particle concentration.

The PAMAS S50DP is equipped with a wear resistant long life ceramic piston pump. The pump provides a constant flow rate of 25 ml/min at a pressure range from 0 to 6 bar.

The PAMAS S50DP counts particles in eight size classes using its 8 sizing channels. 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). The integrated PAMAS HX particle sensor is calibrated in compliance with the ISO 11171 standard, and it measures sample fluids with a maximum concentration of up to 24,000 particles per millilitre at a coincidence error of 7.8%.

For data transfer, the user has the choice between digital and analogue interfaces. A RS485 data interface is standard. Analogue 4-20 mA is also available as an option. The data interface function makes the PAMAS S50DP an effective instrument for condition monitoring.

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