Measuring temperatures at high speed: QuantumX amplifier records motor temperature at Toyota Motorsport test bench

Rapidly and accurately measuring a high number of channels

Kanzenbach works in the chassis department and calibration laboratory, but he was given the responsibility of choosing the measurement technology because of his broad experience in metrology. He started by defining the requirements, which included the capability to provide data from at least 100 measuring points, synchronously and in real time, directly to the test bench. The measurement technology also needed to represent even the slightest temperature variationsv precisely.

"We had narrowed down our selection process to four measuring amplifier systems. Then the HBM QuantumX amplifier won us over in the practical test, especially with its extremely low measurement uncertainty," said Kanzenbach.

HBM delivered eight modules type HBM MX1609 (16-channel thermocouple measurement amplifier type K) for Toyota Motorsport. With its modularly distributable system concept, the QuantumX amplifier flexibly adapts to the number of measuring points and supports all commonly used transducer technologies. Its high measurement accuracy makes it possible to connect the thermocouple plugs directly to the device.

"There is a risk with cable clamps that the measurement will be distorted by the heat emitted from the engine into the room. That problem disappears with this connector solution," explained Kanzenbach. "This also saves us a lot of time during setup. An engine test bench is a complex structure because, in principle, it simulates a complete vehicle including the electronics, cooling circuit and exhaust. So it's quite practical if the more than 100 measuring points can be connected to the measuring amplifier simply by connector, as with the QuantumX amplifier. Then there's no need for additional cabling, which can be very extensive." Connectors also make it easy to convert the system quickly for tests on different engines.

Calculating temperature distribution at different loading levels with real time data

HBM technology is especially user-friendly in practical applications: Before starting up, the thermocouples are conveniently calibrated by the LabVIEW* software via an the QuantumX system's open interface. After, the thermo-transducers are distributed over the motor block, cylinder head and exhaust system and then applied at different depths of the material. The test bench runs through several operating points during the test to simulate different types of loading encountered while driving. The QuantumX amplifier records the temperatures and forwards the information to the test bench system via scalable outputs in real time.

QuantumX temperature measurement with LabVIEW^TM

"Our system is integrated into the test stand measuring system through the HBM QuatumX CANbus Gateway. We have instant access to all temperature data and are able to work with the data," explains Kanzenbach. 300 temperature values per second can be recorded and transferred for each channel at a bandwidth of up to 15 Hz with 24-bit resolution, immune from interference. The thermal calibration of the measuring chain based on only two measurement points allows for a further significant improvement in measurement accuracy. This ensures that even very small dynamic temperature changes will be recorded.

Then the data is combined on the test bench with other engine values such as speed and torque. For very high speeds up to 30,000 rpm, an inertia-optimized torque measurement system is used. The results make it possible to calculate temperature distribution in the engine at different engine loading levels. "With this high-precision measurement of temperatures, engineers can then improve engine efficiency still further," concludes Kanzenbach.

* LabVIEW is a registered trademark of National Instruments Corporation.

Toyota Motorsport GmbH, a leading automotive testing and development company that specializes in high technology, optimizes engines and boosts efficiency with its new test bench, featuring HBM’s QuantumX measurement amplifiers and QuantumX measurement data acquisition system.

"We had narrowed down our selection process to four measuring amplifier systems. Then QuantumX from HBM won us over in the practical test, especially with its extremely low measurement uncertainty."Bruno Kanzenbach, Senior Engineer at Toyota Motorsport GmbH (TMG)  Learn more about Toyota Motorsport GmbH (TMG)