HIAC introduced the first automatic particle counter based on the light extinction principle (light blockage or light obscuration) in 1962. The HIAC particle counter revolutionized contamination control by providing an accurate, reliable and fast method for determining particle levels in hydraulic and lubricating oils (The HIAC name was derived from HIgh ACcuracy). Now, almost 40 years later, another HIAC product is set to change how the industry measures contamination in fluid power and lubricating systems. Still using the now internationally accepted light extinction technology, the HIAC PT 4000 brings affordable particle counting technology directly to the machine, removing the last major source of error in particle counting - sampling errors.
The HIAC PT 4000 can be thought of as a Particle Transducer, and hence the PT model number designation. More importantly, breakthrough technologies used in the design and manufacture of the PT 4000 allows it to be sold at typical transducer type pricing, i.e., at or below $500, rather than at normal particle counter prices. As with a standard particle counter, the particles in the fluid are sized and their concentration measured over a period of time as fluid flows through the PT 4000 optical sensor. The PT 4000 analyzes the particle signals and outputs the particle concentration at the new ISO 11171 sizes of 4 µm, 6 µm and 14 µm. Additional large particle concentration data are provided along with sensor diagnostic information.

The HIAC PT 4000 is supplied in three basic versions for easy installation onto new and existing equipment. Figure 1 illustrates the fluid flow path through the three modules. The PT 4000-3 is a straight through sensor for constant pressure source fluid systems. Module-2 is an inline flow configuration with a built in check valve to divert flow from a varying pressure/flow system. The last module shown, Module-1, has flow inhibitor downstream of the sensor. The PT 4000-1 restricts and controls flow from variable high- pressure sources and drops the pressure to near atmospheric for return to the fluid reservoir.

The HIAC PT 4000-2 and PT 4000-3 each have an integrated sampling port (marked “S” in Figure 1) to facilitate oil sampling for laboratory analysis. These integrated sampling ports ensure that the oil is sampled from the point where the particle count level is determined to be high or out of specification.

In fact, the oil sampling port is an important feature of the HIAC PT 4000 since particles are a leading indicator of a machine’s condition as well as a machine’s contamination level. Rises in particle counts can indicate various conditions of the machine: excess component wear, filter and seal failures, water ingress, cavitation, oil oxidation, poor oil lubrication properties due to viscosity issues and changes in both additive and base oil stock.

To alert the machine operators to changes in the machine’s particle levels the HIAC PT 4000 outputs particle data down an optical communication fiber to the Interface Module (IM). The optical fiber provides de facto noise isolation when used in electrically noisy environments and also simplifies field installation. The optical fiber is strong, durable and can be cut to the required length using a sharp razor blade or knife. There is no need to polish the fiber and the PT and IM units have optical connectors that simply require insertion of the fiber and tightening with a wrench. Interface Modules are available to easily view or integrate the data into an acquisition, logging or control system. The HIAC IM 4000 modules initially offered are:

  • Optical Fiber to RS232 (DTE and DCE versions)

  • Optical Fiber to 0-5VDC

  • Optical Fiber to ModBus (RS232 and RS485)

  • Optical Fiber to LED display of ISO Code and diagnostics data

Additional interface modules are planned and custom designs can be accommodated for OEMs and added value resellers.
Data acquisition is further supported through the availability of a serial port DDE server. If required, a data acquisitions, display and logging software package “Particle Vision Online” is available that provides alarms, graphical trending and data reporting.


For More Information Contact:
Peter Rossi, VP Condition Monitors
Pacific Scientific Instruments
481 California Avenue
Grants Pass, OR 97526
Phone: 541-479-1248 or 800-866-7889