On-Board Spark Plug Center Electrode Temperature Measurement with Wireless Data Transmission

To increase reliability and the maintenance interval of an internal combustion engine while operating it with the lowest possible emissions, spark plug wear must be reduced. In this context, information about the spark plug center and the ground electrode temperature is key. Several measurement devices have been developed that measure the temperature of spark plug electrodes. The great challenge is to measure the temperature of the center electrode; on the one hand, the measurement device must be insulated and capable of withstanding the high voltage of the ignition system, and on the other hand, the device should not influence the ignition system. All previously studied devices presented in this paper have in common that major reconstruction of the ignition system and/or spark plugs whose design is very different from the standard engine spark plug were necessary. Other systems were presented in which most parts of the ignition system were completely different from the standard parts. The disadvantages of these systems are that great effort is required to apply the measurement system and that engine behavior and the spark plug temperature differ from that of the standard engine. This paper presents a measurement device and setup to obtain the spark plug center electrode temperature in standard engines; both the spark plug and the ignition system of the standard engine were used with minor customization. The data transmission is wireless in order to protect the test bed temperature data acquisition system from the high voltage of the ignition system and to minimize the influence of the modification on the ignition system.