The Mustang Dynamometer I/M 240 system consists of all of the following components as outlined in more detail in USEPA “IM240 and Evaporative Test Guidance: 1998 Revised Technical Guidance” Report EPA-AA-RSPD-IM-98-1 (Draft) and other appropriate sections of USEPA 40 CFR 85.

DYNAMOMETER
A very highly advanced device that consists of a set of carefully controlled rollers upon which a vehicle is driven to exactly simulate the conditions experienced while driving down the street. During the IM 240 test, the subject test vehicle is driven on the dynamometer for a period of 240 seconds (4 minutes) at speeds varying between zero MPH and 57.6 MPH. This test is taken from the EPA’s Federal Test Procedure (FTP) and closely resembles an average driving cycle in a major urban area.

Dynamometer specification

CONSTANT VOLUME SAMPLER (CVS)
This device takes the total mass sample of exhaust emission through a large volume pipe and calculates the total mass of air and exhaust pollution for a given driving period upon the dynamometer.

ANALYTICAL SYSTEM
This is the Electronic Analysis Device through which a sample of the exhaust gas is passed to calculate the exact ratios of Carbon Monoxide (CO), Total Hydrocarbons (THC), Carbon Dioxide (CO2) and Nitrous Oxides (NOx). In conjunction with the CVS, these ratios are then expressed in total pollution figures of all exhaust pollution in Grams per Mile, as required by the USEPA.

Analyzer specification

ANALYTICAL SOFTWARE AND DRIVERS AID
This is the Pentium based PC based control software that is displayed upon the computer monitor to display the correct 240 second driving cycle and to guide the operator step by step through the operation of the I/M 240 system. This software automatically makes the pass/fail decision based upon the Exhaust Emission readings obtained during the I/M 240 driving test, when compared to the State supplied data base for passing or failing vehicles, dependant upon the year, make, manufacture, engine size, type of transmission and vehicle gross weight contained in the memory of the system.

FUEL CAP PRESSURE DECAY TESTER
This device is a portable tester that, through the use of the correct adapter, accepts the vehicle gas cap and applies a pressure to check for leaks. After the test, an automatic pass/fail decision is displayed for the operator’s action.