Good Afternoon, I work for the North Carolina Department of Agriculture and Consumer Services, specifically as the Director to the Standards Division, which includes our fuel quality program. Historically our compliance rate for fuels is usually 97-98% per year and we generally test between 25,000-30,000 sample a year (gasoline, diesel, kerosene and motor oil). I understand there may be some interest in using alternative methods for determination of octane numbers and thought I could share some of our experiences. We have about 13 Zeltex units that use Near Infrared (NIR) technology to predict the octance number (one for each field inspector, the field supervisor and the lab). We essentially purchased one per year since the early to mid 1990's, most recently trading in older units to defray the cost of new ones. Some of our newer units include programs for ethanol or cetane as well. We will approve a sample on octane using this unit, but we will not condemn one. Any approved results are noted as "NIR" on the inspection transcript so that is is clear it was not an engine result. The unit provides RON, MON and the index (average). Our lab does have four octane engines (2 research method and 2 motor method). A sample can be run in about 45 second or less. A sample is poured into the test jar (about 200 ml). The unit is run once without the jar in place, then twice with it in place (turn in 180 degrees between runs) then an analyze button is pushed (without the jar in place). The fuel in the jar is returned to the sample container. For the engine, we use 1 quart of sample split between the two engines. We have a 2nd 1 quart can that we use for vapor pressure, sulfur, distillation and ethanol content, but the remainder could be used in the engines if necessary. The benefits we see are mainly in the field, as it allows for very quick on site testing, especially if a technician is there to correct a blending issue with a dispenser(s). They can make an adjustment and then we can determine if the fuel will then meet the octane specs as posted (there is often some line flushing that goes on here as well). Many stations now have blend pumps or have the single hose multi-product units, so it does save us from having to draw larger samples for the lab since we do multiple dispensers at each location. Otherwise and sample would have to be sent to the lab, each field inspector has certain days their sample come into the lab, to be tested the next day and then the results reported, so turn around time is no longer a factor. If we do have a sample that is boderline, we conditionally approve it, meaning we leave the pumps open and take a sample for the lab to determine if it meets specs or not using the engines. On occassion we will test the same sample on both the Zeltex and our engines, generally the results are the within a couple of tenths of each other. We find this a very useful and efficient screening tool for octane results and may be worth your consideration.