Finally - a pressurized automated liquid sampler (PALS) for the fields of hydraulic oil contamination monitoring and pharmaceutical particle size analysis for viscous and volatile fluids. This batch sampler has such unique features as: a self sealing sample chamber, programmable volumetric settings from 0.1 to 100 ml per cycle, automatic flush cycle, computer controlled and monitored sample chamber pressure and corresponding fluid flow rate.
 
Couple this with state of the art counting/sizing electronics and a host of wide dynamic range sensors and you have a system that is hard to beat. The heart of the system is the AccuSizer 580 high resolution pulse height analyzer that can count and size particles one at a time. Its DSP based architecture allows for user settable software channels that can accommodate 2-32 tabular channel thresholds with corresponding particle count levels for determining pass/fail criteria of hydraulic fluids or pharmaceutical injectable drugs. A single click of the mouse converts the 32 channel data to 128 logarithmically spaced channels for high resolution particle size determination.
 
There is also a modular family of sensors covering the size range from 0.5 to 2500 microns. These sensors are based on the time proven method of light extinction. Each sensor provides the dynamic range and solvent compatibility for even the most demanding applications. The fluidics package combines computer controlled automation with a flexible design that can be configured in the field. Unique features include: self sealing sample chamber that provides a targeted placement of sample container, allowing for one handed insertion of sample bottle; continuous monitoring of air pressure and sample fluid flow with greater than 0.1 mL fluid volume sensitivity and control; quick disconnect user interchangeable critical orifices for use with volatile fluids; enclosed air exhaust port allowing for safe venting of chamber air; provision for pressurized air from multiple sources including air tanks, house air, compressor etc...; inline filtration and dehumidification provided for external air sources; computer controlled flow providing greater accuracy for small volume injectable analysis (SVI's); shielded clear sample chamber with a unique design that places minimal axial force on the glass sample chamber; multiple position sample feed tube allowing for non centered and adjustable elevation sampling. User defined tare/dead volume allows for intra- and pre- analysis flow, ensuring accurate particle sizing.
     
Now a complete analysis run can be accomplished with a single click of a mouse. Just place the sample container on the target pad and click on the run button. The stage will automatically: seal, lock, pull a vacuum in multiple stages to degas the sample (optional), re-pressurize to the proper level to produce a flow rate of the liquid as defined by the sensor calibration, sample a volume as defined by the pre analysis dead volume (optional), and measure single or multiple aliquots of the sample, display the results in one of the many predefined formats, save the raw data in over 512 differential channels, drain the system, lift the stage allowing removal of the sample bottle and produce a report with both graphical and tabular data that includes pass/fail criteria as defined by any standard that the user would like to include as part of the configuration file. All that the user has to do is place the next sample on the target pad and click on Run. Nothing could be easier!
 
The software is a Windows based controller that not only provides true multi-tasking capabilities, saving time and money, but also offers the unique features found on most leading edge Windows programs including: copy and paste features, allowing users to import tables and graphs into other Windows documents for custom report generation, multi-level operational control with password protection, user definable criteria tables for embedding contamination standards into the software program. The system provides pass/fail alarms, multi-level data archiving, real time data transfer to popular database and spreadsheet Windows programs and unlimited user defined customizable report templates. The PALS system is designed using a modular approach and has provisions for automated (robotic) sample introduction and at-line process monitoring.
 
 

   

Figure A is a typical result obtained from hydraulic oil that is being used by the Navy. The table is set up based on the the NAV AIR Classification system. Five size classes ranging from 5 to over 100 microns are reported. Two runs were taken to insure reproducibility and the results were displayed on a particles per 100 mL basis. Statistical information on the combination of runs is also available as well as sample identification numbers. The class is reported on the heading of the table (CLASS 1).