I/M SOLUTIONS 2012 Training Forum for Jurisdictions Opacity Testing in I/M Programs Using Acoustics to Ensure Proper Testing

I/M SOLUTIONS 2012 Training Forum for Jurisdictions 2 Personal Bio 20+ Years in Emission Testing Industry 3 Years with EPA 17 Years with SPX Service Solutions Company Bio Long history in the I/M business: Allen, Bear, OTC, Actron, DieselTune BAR84, BAR90, BAR97, ASM, NYTEST, J1667 (Opacity) Testing, OBDII Testing – many types of equipment, and many test methods The DX240 DieselTune smokemeter was certified to meet J1667 in Ontario Subsequently certified for testing in Massachusetts and New York. The DX270 is the newest generation of the DX240, adding the ability to detect the probe in the exhaust of the vehicle via acoustical measurement The DX270 is now being used in the MASS08 program, and is being delivered for use in the Ontario program Experience in the I/M Industry

I/M SOLUTIONS 2012 Training Forum for Jurisdictions 3 J1667 SAE Test Procedure written in 1996 Defines a procedure for testing the opacity of diesel fueled vehicles by using the inertia of the engine to provide a load. The operator performs a ‘snap’ acceleration Equipment gathers the opacity data and performs averaging to calculate a ‘peak exhaust smoke level’. The window of data that are used to capture the exhaust measurement are determined based on a ‘trigger point’ from when the operator snapped the throttle RPM Measurement J1667 suggests using rpm measurement as the trigger to help ensure repeatability of the test In practice, rpm has been found to not be reliable, so triggering based on a rise in opacity came to be acceptable If no rpm, and no detectable opacity (very clean vehicle) then a ‘timeout’ occurs so the operator does not overstress the engine In practice, rpm has also been used as a means to discourage fraudulent testing (if there is an rpm measurement, the car was likely tested properly…) Brief History of Opacity (J1667) Testing

I/M SOLUTIONS 2012 Training Forum for Jurisdictions 4 Difficult to Obtain a Signal Many different methods… ‘Battery’ tach Optical tach Fuel Injector rail (pressure) transducers Sound/vibration transducers All different approaches with varying degrees of success Expensive Another piece of equipment to purchase and maintain The best methods (most reliable) are the most expensive Unwieldy Time consuming More cables and connections to deal with The Problem with RPM Measurement

I/M SOLUTIONS 2012 Training Forum for Jurisdictions 5 Technology Patented method of using a microphone to ‘listen’ to the exhaust The microphone is built into the enclosure of the smokemeter (no additional equipment to hookup). The software in the meter will ‘seek’ different acoustic levels if the idling sound is too quiet or too loud Test Methodology The probe is inserted into tailpipe User is instructed to start the engine Equipment ‘listens’ for a baseline, then sets a predetermined ‘threshold’ that must be met in order to trigger the data on acoustics If the idling cannot be heard, the user is given prompts to ensure the probe is inserted Once the baseline acoustic level has been determined, the user is instructed to snap and hold the throttle in the vehicle If snap is ‘heard’ the test triggers on acoustics If the smoke is seen in the meter before an acoustic trigger, the test triggers on opacity If the programmable timer ‘times out’, the meter will still measure the opacity, and record time as the trigger. These should be the least common triggers. Using Acoustics Instead of RPM

I/M SOLUTIONS 2012 Training Forum for Jurisdictions 6 Vehicle Inspected May be used to identify vehicles that are difficult to pick up an acoustic signal Method Used to Detect the ‘Snap’ Event Acoustics detected (the meter ‘heard’ the acceleration) - or Opacity (the meter ‘saw’ the rise in opacity) - or Time (the meter could neither ‘hear’ nor ‘see’…) Captured for each of the snap events (up to 9) that occurs over the course of the test Opacity Levels The value(s) used to determine if the vehicle passed the inspection Also captured for each of the snap events Overview of Data Gathered Example 1 – All three Official snaps triggered on Acoustics, and average Opacity was 6.7% Example 3 – All three Official snaps triggered on Time, and average Opacity was 0.0% Example 2 – First snap triggered on opacity, next 2 on acoustics – average was 25.3%

I/M SOLUTIONS 2012 Training Forum for Jurisdictions 7 Problem Stations Can be Identified Rather Easily Target your ‘outliers’ for audits based on a high rate of time triggers Expect to see a high correlation between high time triggers and low opacity readings Sample Analysis Table of Stations sorted on the % of inspections triggered on a ‘Time Out’

I/M SOLUTIONS 2012 Training Forum for Jurisdictions 8 Look for Continuous Improvement Over time, the % of tests triggered on time should decrease as fraudulent testing diminishes. Likewise, the % of Acoustic triggered should increase… Sample of Analysis Monthly Statistics Showing gradual decline of Time Triggers and rise in Acoustic Triggers

I/M SOLUTIONS 2012 Training Forum for Jurisdictions 9 Acoustics Can be Used to Ensure Proper Testing Facilities have been identified for incorrect testing using acoustic data Much simpler test compared to rpm hook up Areas for Further Investigation Identifying vehicle ‘types’ that acoustics does not work well Implementing more ‘real time’ triggers for suspect testing Summary

I/M SOLUTIONS 2012 Training Forum for Jurisdictions 10 Massachusetts DEP SGS Testcom Applus Technologies Acknowledgements The following organizations provided data and/or supporting analysis that contributed to this presentation: