Since 1982, ESP has performed 12.8 million tests at our state program facilities and implemented every type of test available throughout our facilities. Most recently, we have upgraded several state programs with OBD II tests.
ESP has pioneered the development and implementation of remote sensing technology, which has been approved by the EPA for use in conjunction with traditional inspection and maintenance (I/M) programs.
ESP offers 15 types of tests that government programs can choose from to have implemented into their program specifications. We have been instrumental in the design and specification development of the equipment that performs these tests.
The most frequently used tests include:
The United States EPA and the European Union require automakers to include On Board Diagnostics (OBD) in all cars, vans and light duty trucks beginning in the model year 1996 in the US and 2000 in Europe.
On-Board Diagnostics (OBD) equipment tests vehicles equipped with OBD technology for engine performance and it can detect problems with the emissions control system before the driver is aware of them. The system monitors for malfunction or deterioration of the power train and its emissions-control systems on a constant basis.
The OBD test is conducted by attaching a cable to the vehicle's on-board computer through a data link connector (DLC) usually found under the dashboard and information is downloaded to a computer regarding the vehicle's emissions systems.
The USEPA provides a regulatory framework whereby states can complement their existing I/M programs with an effective Remote Sensing monitoring and enforcement system. Remote Sensing, when applied to vehicle emissions testing, refers to the measurement of vehicle exhaust emissions with roadside monitoring systems (known as remote sensing devices or RSDs), as the vehicle passes by, without interfering with, or altering the vehicle progress. Infrared (IR) and Ultraviolet (UV) light beams are directed across the road and passively reflected back to detectors that monitor light intensity at characteristic wavelengths. The amount of characteristic infrared or ultraviolet light absorbed is translated into the exhaust concentration of the three regulated pollutants of interest, carbon monoxide, hydrocarbons and nitrogen oxides. Vehicle emissions levels are measured within one second, then catalogued in a database and matched automatically with the license plate number.
Typically, vehicles idle for 30 seconds, and are then accelerated to 2500 revolutions per minute for 30 seconds, and then back to idle for 30 seconds. A probe, placed in the tailpipe, collects information on the vehicle's hydrocarbon, carbon monoxide, oxygen and carbon dioxide exhaust emission's concentration levels, that are measured in a four-gas analyzer. The single or two-speed idle test is part of a basic emissions inspection program used in moderate or marginal non-attainment ozone areas, and for vehicles that can not be tested on a dynamometer, such as vehicles equipped with Automatic Braking Systems (ABS) and permanent All Wheel-Drive vehicles.
ASM testing uses a five-gas analyzer and dynamometer (a treadmill-like device that spins the front or rear tires of the vehicle under load). An exhaust probe, inserted into the vehicle exhaust pipe collects and passes a sample of the exhaust to the five-gas analyzer as the vehicle is operated at a steady state load in the range of 15 to 25 mph (25 to 40 kph). This procedure more effectively measures vehicle emissions by simulating actual driving conditions, while the vehicle is under load. The test measures concentration levels of hydrocarbon, carbon monoxide, carbon dioxide, oxygen and nitric oxide. Oxides of nitrogen, measured as nitric oxide, are only produced when vehicles are under load, making a loaded mode test mandatory in serious, severe or extreme ozone non-attainment areas with urbanized populations over 200,000.
New vehicles are certified using the US Environmental Protection Agency (USEPA) Federal Test Procedure (FTP) that measures and records exhaust emissions in grams per mile or kilometer for each pollutant while the vehicle is subjected to a simulated 7.5 mile transient dynamometer loaded test cycle.
For in-service testing, the USEPA specified the I/M 240 test, which is similar to the FTP but with a shorter duration of 240 seconds and less stringent emissions limits (cut-points) to allow for some vehicle degradation and a different test cycle. ESP was the first company to develop and implement the I/M 240 test in centralizedtest lanes and we currently operate more than 450 I/M 240 test lanes in seven programs. The I/M 240, consists of a high-grade emissions analyzers, a precision constant volume sampling system (CVS) and a full inertia simulation dynamometer.
ESP was a major contributor to the development of a lower cost system, IG240, or Mass Emissions Transient Test System (METTS) for use in decentralized programs. METTS uses a similar exhaust dilution method as the IM240 but measures "raw" undiluted exhaust, enabling the use of lower cost BAR 97 emissions analyzers. The IG240 dynamometer also provides road load and inertia simulation using a different concept than the I/M 240 dynamometer, enabling a significantly lower cost for this component. Three decentralized states adopted METTS to meet the USEPA emissions reductions targets and ESP has more than 3,000 systems operating reliably in these programs.
The USEPA determined that leaking gas caps is a major cause of excess hydrocarbons and a major contributor to increased ozone levels, so recent regulations require a test of vehicles' gas caps. The test consists of inserting the gas cap into an adapter and applying pressure to the gas cap. To assist the operator, the test computer displays the correct adapter to use. The test measures leak flow rate to determine whether the gas cap seal is sufficient to prevent gasoline from evaporating into the air from the vehicle's tank. The test computer sets the target pressure for each test.
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