UL offers field evaluation services for medical devices and laboratory or test and measurement equipment that cannot be assessed in our facilities. Our experienced engineers assess the product in the field to applicable standards for regulatory acceptance.
Jet engines move the airplane forward with a great force that is produced by a tremendous thrust and causes the plane to fly very fast. All jet engines, which are also called gas turbines, work on the same principle. The engine sucks air in at the front with a fan. A compressor raises the pressure of the air. The compressor is made with many blades attached to a shaft. The blades spin at high speed and compress or squeeze the air.
How Automobile Ignition Systems Work. The spark plug is in the center of the four valves in each cylinder. Â­The spark plug is quite simple in theory: It forces electricity to arc across a gap, just like a bolt of lightning. The electricity must be at a very high voltage in order to travel across the gap and create a good spark.