CBSE Class 8 Answered

Process of testing pollution check in vehicles:

• Gas Cap Pressure Check: It tests to see if a vehicle's gas cap is effectively keeping fuel vapors from escaping.
• The Second Generation On-Board Diagnostics (OBD II) Test: During this simple test, data is downloaded from the vehicle's on-board computer to check for emissions equipment malfunctions.
• The Inspection and Maintenance (I/M 93) Test: During this test, an inspector drives the vehicle on a treadmill device called a dynamometer. The test simulates driving on a road. While driving, the vehicle's tailpipe emissions are captured and analyzed to evaluate the effectiveness of the vehicle's emissions control equipment.
• The Single Idle Speed (BAR 90) Test: A metal probe is inserted into the vehicle's tailpipe while the vehicle idles to sample the exhaust stream. At the same time, a sensor is placed on the hood of the vehicle to measure the engine speed. The probe measures the vehicle's emissions and they are analyzed to determine whether or not the vehicle's emission control equipment is working properly.