TRI offers a superior methodology for sampling oil mist and particulate for compressed air testing. TRI’s high surface area, low velocity methodology utilizing a glass fiber filter is recommended by the Compressed Gas Association (CGA) and the National Fire Protection Association (NFPA). TRI’s oil mist and particulate sampling equipment is capable of isokinetic sampling. The filter sample test is performed at the full flow rate of the air/gas supply simulating operational use. This helps ensure that the contaminants suspended in the air/gas stream reach the sampling equipment. The TRI filter captures a truly representative sample of the oil mist present in the air stream. Tests of other vendor’s methods (which allow a high-velocity air stream to flow through a very small filter) indicate that up to 80 percent of oil mist present in the air stream is not even collected on the filter. This means that even though those vendor’s analytical methodology may be acceptable, their method for sample collection is poor.
TRI Test Equipment
The compressed air/gas source is connected to TRI’s test equipment through the input fitting. The air/gas expands within the test equipment which lowers the pressure to a safe working pressure of 4 to 25 psi. All of the air/gas passes through a preweighed glass fiber filter which collects all the oil mist and particulate in your air/gas stream. A portion of the air/gas flows into the gas sample bottle and the remaining air/gas passes through an interchangable orifice place and out through the exhaust muffler. TRI’s test equipment allows for the passage of at least 500 liters of air/gas through the filter at a required flow rate as recommended by the CGA and NFPA.
TRI Analytical Technique
The oil mist/particulate sample is returned to the laboratory and placed in a desiccator for a minimum of 8 hours to remove moisture and then reweighed on a NIST- traceable analytical balance. Based on the time the sample was in place, the pressure reading on the test equipment gauge and the orifice plate used, TRI calculates the air volume. We report your oil mist and particulate results in mg/m3. If the sample returned to the laboratory is analyzed and determined to approach the upper limit of the specification, a second filter procedure is performed to determine the breakdown of oil mist versus particulate in the sample.
If requested when ordering, the oil mist/particulate sample can be analyzed and the second filter procedure can be performed to determine oil mist versus particulate breakdown even if the sample does not approach the upper limit of the specification. This is often used by companies to determine if any oil mist and/or particulate was detected in the sample.