Category Archives: Education

Sound Measuring Equipment

DPS Technical supports responsible OHV recreation and believes that excessive sound levels are a main cause of complaints against the sport.

Since 2004 DPS Technical, Inc. has supplied equipment and training for hundreds of OHV law enforcement officers and civilians throughout North America and these dedicated individuals perform sound level tests when possible.

A need for more citizen involvement in voluntary OHV testing has been identified. To remedy the lack of equipment for citizens to provide voluntary OHV sound level testing, DPS is implementing a Sound Testing Equipment Kit Program.  The testing kit includes a Calibrated Type ll sound meter, tachometer, tape measure, storage box and other items necessary to perform spark arrestor inspections, or the SAE 1287 OHV field sound test or the SAE 2825 On Highway Motorcycle sound test procedure.

For further information on the program or to apply contact DPS Technical, Inc. – Chris Real at (909) 981-5228.

DPS Technical also has sound measurement training classes for civilians and law enforcement personnel. Many of the classes are held under contract and sponsored by The State of California OHV Division. To receive information on our training schedule in your area contact DPS Technical for details.

Chris Real, CLS   President
DPS Technical, Inc.
1160 Dewey Way, Suite D
Upland, CA 91786
(909) 981-5228 T

Development of the J2835 On-Highway Motorcycle Sound Test Procedure

motorcycle-industry-council-logo1The MIC, MIC consultant Tom Austin (Sierra Research), MIC member Chris Real (DPS Technical, Inc.), and SAE Motorcycle Technical Steering Committee Chairman John Lenkeit (Dynamic Research Inc.) co-authored a paper on the development of the SAE J2825 on-highway stationary sound test procedure. The SAE published the paper, which was presented at the 2011 SAE Noise and Vibration Conference in Grand Rapids, Michigan on May 17th. The 14-page paper details the field testing, data analysis, evaluation of test site conditions, validation testing and even field testing.

In response to a growing need for a practical and technically valid method for measuring exhaust sound pressure levels (SPL) of on-highway motorcycles, the SAE Motorcycle Technical Steering Committee has developed Surface Vehicle Recommended Practice J28251, “Measurement of Exhaust Sound Pressure Levels of Stationary On-Highway Motorcycles,” which includes a new stationary sound test procedure and recommendations for limit values. Key goals of the development process included: minimal equipment requirements, ease of implementation by non-technical personnel, and consistency with the federal EPA requirements; in particular, vehicles compliant with the EPA requirements should not fail when assessed using J2825. Development of the recommended practice involved a comprehensive field study of 25 motorcycles and 76 different exhaust systems, ranging from relatively quiet OEM systems to unbaffled, aftermarket exhaust systems. For the various motorcycle/exhaust system configurations, SPL measurements were made using the EPA pass-by procedure and several different stationary measurement methods.

Acoustical Society of America presentation

Los Angeles, CA – May 2004

The team of Dr. Robin T. Harrison, P.E. & Chris F. Real, CLS presented “Off-Road Vehicle Noise Control” to the members of this premier technical society.  The members were treated to an overview of Rob & Chris’ thirty-five years of research activities in this industry, and were encouraged to ask questions on historical events, as well as the latest technology from the racing community.

Acoustical Society of America  –  05-18-2004 – Off-Road Vehicle Noise Control

Technical Presentations

Portland, Oregon – March 2004

Chris Real presented an educational environmental topic to the nation’s land managers in Portland, Oregon.  The presentation addressed issues such as “Safe Chemical Disposal and the Off-Highway Environment”, “Race Day Chemical Disposal”, and “OHV Sound Measurement Equipment and Training”.  The ChemHelp / National Off-Highway Vehicle Conservation Council (NOHVCC) workshop handout is available by contacting Chris Real at DPS, Inc – ChemHelp – or (909) 981-5228.  DPS, Inc. will be hosting a technical discussion sound training class and demonstration at the NOHVCC director’s meeting in Richfield, Utah 09/30/2004, the Richfield ATV Jamboree, and at the 2005 NOHVCC land manager’s conference (03/05) in Ontario, CA.