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  • Emission test cycle

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    An emission test cycle is a protocol contained in an emission standard to allow repeatable and comparable measurement of exhaust emissions for different engines or vehicles. Test cycles specify the specific conditions under which the engine or vehicle is operated during the emission test. There are many different test cycles issued by various national and international governments and working groups. Specified parameters in a test cycle include a range of operating temperature, speed, and load. Ideally these are specified so as to accurately and realistically represent the range of conditions under which the vehicle or engine will be operated in actual use. Because it is impractical to test an engine or vehicle under every possible combination of speed, load, and temperature, this may not actually be the case. Vehicle and engine manufacturers may exploit the limited number of test conditions in the cycle by programming their engine management systems to control emissions to regulated levels at the specific test points contained in the cycle, but create a great deal more pollution under conditions experienced in real operation but not represented in the test cycle.

  • Tube tester

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    A "Sylvania Electric" multimeter tester for vacuum tubes A tube tester is an electronic instrument designed to test certain characteristics of vacuum tubes (thermionic valves). Tube testers evolved along with the vacuum tube to satisfy the demands of the time, and their evolution ended with the tube era. The first tube testers were simple units designed for specific tubes to be used in the battlefields of World War I by radio operators, so they could easily test the tubes of their communication equipment.

  • Portable emissions measurement system

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    A CATI PEMS being strapped down inside a vehicle A portable emissions measurement system (PEMS) is a vehicle emissions testing device that is small and light enough to be carried inside or moved with a motor vehicle that is being driven during testing, rather than on the stationary rollers of a dynamometer that only simulates real-world driving. Early examples of mobile vehicle emissions equipment were developed and marketed in the early 1990s by Warren Spring Laboratory UK during the early 1990s, which was used to measure on-road emissions as part of the UK Environment Research Program. Governmental agencies like United States Environmental Protection Agency (USEPA), European Union,, and various states and private entities have begun to use PEMS in order to reduce both the costs and time involved in making mobile emissions decisions.

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