Abstract: An apparatus for measuring the pressure within the torque converter of an automatic transmission. The apparatus includes a sensor to sense the interior pressure of the torque converter and generate an electrical signal representative of that pressure. That signal is converted to microwave energy which is radiated into the interior of the torque converter housing from a microwave transmitter located within the torque converter. Receiving microwave antennae exposed to the housing interior receive the microwaves and transmit an electrical signal corresponding to the microwave energy to a remote readout external of the torque converter. The receiving antenna are preferably in the form of resonant slots in the torque converter housing and the slots have a length related to the wavelength of the generated microwaves.

Abstract: An apparatus for measuring the temperature of a piston in an internal combustion engine. The apparatus includes a thermistor to sense the temperature of the piston and generate an electrical signal representative of that temperature, a transmission unit connected to the thermistor for receiving the electrical signal and for converting the signal to an infrared beam for transmission to a point remote from the piston, and a receiver to receive the beam and convert the beam to an electrical signal corresponding to the electrical signal generated by the thermistor. The first mentioned electrical signal is converted to a rectangular wave form prior to transmission of the infrared beam.

Abstract: A process of separating wood chips according to their bark content by orienting them between a light source and light detector, measuring the amount of light transmitted through each chip, and separating the bark-laden chips from the bark-free chips on the basis of their light transmittance. An apparatus for separating wood chips according to their bark content, comprising a light source, a light detector, means for properly orienting the wood chips between the light source and detector, and means for differentiating between bark-laden chips and bark-free chips on the basis of their light transmittance.