BR(E)AKING NEWS!!! - MTI Instruments - #1

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MTI Instruments, Inc. 325 Washington Avenue Extension Albany, NY 12205 PH: +1-518-218-2550 OR USA TOLL FREE: 1-800-342-2203 FX: +1-518-218-2506 sales@mtiinstruments.com www.mtiinstruments.com APPLICATION NOTE Brake Rotor Testing Using Capacitance Sensors Introduction As we venture onto our highways we hardly give much thought to the operation or complexity of our vehicle braking system. We only think about it when we have to suddenly slam on the brakes to avoid an impending catastrophe. At that instant we hope and pray our car will stop in time for our safety, and the safety of others. Most don’t realize the extensive design and testing that goes into braking systems to insure we stop in time. Take the brake rotor for example (see fi gure 1). Under normal operating conditions it is subjected to extreme temperatures and forces, which causes rotor distortion and possible failures. To make certain it can withstand these conditions, extensive laboratory testing is performed to refi ne the design for longevity, short stopping distance and vibration free operation. Production lines are equipped with inspection equipment to provide 100% assurance that poor quality products are not used. Extensive on-vehicle testing is done under real life conditions to test prototype units and engineering designs. Test vehicles are driven for long periods of time while brake performance is monitored by a variety of sensors and data acquisition systems. For effi ciency reasons brake rotors are becoming lighter, thinner and designed with cooling vents to improve performance. These changes continue to reduce the braking surface, forcing designers to consider alternative materials and designs. This is where MTI Instruments (MTII) comes in. The Driving Test In order to simulate what a driver encounters on a daily basis, test vehicles are equipped with both displacement and temperature sensors to actively monitor the brake rotor. Data on disk runout, disk thickness variation (DTV), disk “coning” (warpage), and temperature are continuously collected and monitored from inside the vehicle. A combination of city, country and highway driving courses are set up along with many designated braking locations to fully simulate in days what a driver typically experiences in weeks or even months. This information is used so that brake designers can determine how long a braking system will operate and its overall performance. Once a design is proven, mass production begins. MTII appnote: breakrotors.pdf - Page 1 of 2 Figure 1