The German company PAMAS develops and manufactures Automatic Particle Counters for fluid contamination control. The company product range includes measuring instruments for long-term condition monitoring of liquids such as hydraulic or lubricating oil and for contamination analysis of particulate matter in water, pharmaceutical suspensions, and other fluids. Intended for stationary online measurement of dark fluids, the company has developed a new particle counter: the PAMAS S50DP. With an built-in dilution system, this online particle counter dilutes dark sample fluids prior to measurement thereby reducing the sample’s turbidity level.
Fluid cleanliness of oil, water, or a fuel, for example, can be monitored through optical particle counting. An automatic particle counter measures particulate contaminants in the fluid. Conventional or optical particle counters work with the help of light. In optical measurement proceedings, the light beams through the liquid. The electromagnetic waves may be deflected or absorbed when meeting the particles in the measuring cell. The light effect on the particles is analyzed with the help of a previously calibrated optical electronic hardware. The measuring result provides information on the number of particles per milliliter and on the size of each single particle.
The technique has its limitations. In case of dark fluids, for example, the sensor’s laser beam is not able to penetrate the medium. To enable particle counting of dark fluids, the sample fluid’s absorption must be reduced before analysis. The optical particle counting technique is also difficult to use when the level of contamination greatly exceeds the sensor’s maximum particle concentration level, when the fluid contains undissolved additives or if the sample’s viscosity is too high for an accurate measurement. In such cases, sample dilution with solvents helps makes accurate counts. For batch and bottle sampling, the dilution agent is manually added. However, when operating fluids are analysed online, an online particle counter is directly built-in as a fixed installation, as it would be needed in hydraulic or lubricating oil systems, or in a fuel tank. The sample liquid is drawn from the system via a bypass line and analyzed directly online during operation.
For continuous condition monitoring of difficult fluids, such as those mentioned, the company has developed a new online particle counter: The PAMAS S50DP online particle counter has an automatic dilution system that adds a programmable amount of solvent online to the difficult sample. The system’s inner structural design ensures that the solvent and sample fluid are thoroughly mixed. This helps to get a good homogeneity of the mixture and hence accurate, repeatable 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: Highly contaminated liquids. Without prior dilution, the coincidence error quote of such sample fluids would be too high due to particle over concentration.
The PAMAS S50DP comes with a wear resistant ceramic piston pump for a constant flow rate of 25 ml/min at a pressure range from 0 to 6 bar. With its eight different size channels, the unit 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). The unit’s 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 milliliter at a coincidence quote of 7.8%.
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 free from interference. The optional analogue 4 to 20 mA channel transmits data to a PLC (Programmable Logic Controller). This interface function makes the PAMAS S50DP an effective instrument for condition monitoring.
To roport and analyze measuring results, PAMAS provides two different software tools: The online visualization software PAMAS POV has been developed for the online visualization of measuring results and for long-term trend monitoring. 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.
The company will present its newly developed PAMAS S50DP, at the Hanover Fair 2015, Hall 23 at Booth A49.
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