Abstract: The invention provides an arrangement for detecting ionization in the combustion chamber of a combustion motor where the fuel self-ignites by means of compression, as well as associated measurement device and calibration devices. A measurement tip extends substantially down into a main combustion chamber, which provides access to the portion of the combustion chamber where combustion first starts. The measurement device has a simple construction with good thermal conductivity. Using the calibration device according to the invention, the performance of the measurement device can be optimized from the point of view of control in different combustion motors in which the characteristic ion stream signal for each type of motor can be correlated against pressure data from combustion and used to calibrate the motor.

Abstract: A glow sensor which combines functions of a diesel engine glow plug with an ion sensor for sensing engine combustion initiation and characteristics includes a ceramic rod retained in a supporting ceramic sleeve carried by a metal shell mountable in an engine cylinder head. The ceramic rod includes a heating element in a glow tip at the inner end of the rod which, in use, extends into an engine combustion chamber or pre-chamber. A conductive material such as platinum or palladium is coated on the lower end of the glow tip and connected by a conductor with a source of electric voltage. In use, the voltage produces a current carried by electrons generated by ionization of the combustion chamber gases during combustion. The current varies with the degree of ionization and the amount of electrons generated during various phases of the combustion event. The resulting information is usable in controlling engine operation or evaluating its operation for test purposes.

Abstract: A method and apparatus for controlling a solenoid-operated valve element are provided. The valve element is movable between first and second end positions, and is urgable toward the first end position by magnetic attraction caused by activation of the solenoid and is normally urged toward the second end position. The method further enables detection of the time at which the valve element returns to the second end position from the first end position after deactivation of the solenoid.