Abstract: A liquid flow rate detector adapted for detecting whether a rate of flow for liquid flowing through a conduit is above or below a generally predetermined liquid flow rate, and for developing different control signals in response to detecting flow rates above and below that generally predetermined liquid flow rate.

Abstract: A measurement apparatus is provided for use with a moisture tester of the type wherein the moisture content of a sample is determined as a function of the change in capacitance of a sample-receiving test cell when a sample is present therein from the capacitance of said test cell when empty. The tester also includes a reference oscillator and a test cell oscillator in circuit with the test cell, and a variable capacitor coupled in circuit with the test cell and the oscillators for bringing respective outputs of the two oscillators into a balanced condition both with the test cell empty and with a sample present in the test cell. The variable capacitor comprises a fixed member and a movable member which is rotatable through 360 degrees relative to the fixed member.

Abstract: A monitoring circuit is provided for a metal detector which includes a metal sensor for producing a sensor signal in response to the passage of a metallic object through a rotating apparatus and a tachometer for producing a tachometer signal at a frequency proportional to the rate of rotation of the rotating apparatus. In accordance with the invention, the monitoring circuit comprises an adjustable tracking filter responsive to a predetermined control signal for tracking the frequency of the sensor signal in a predetermined fashion and a control circuit responsive to the tachometer signal for producing the control signal.

Abstract: A modular monitoring and control system is provided for an agricultural machine such as a combine. The system includes an executive processing unit which is capable of cooperating with one or more monitoring and/or control modules, which module may be added to or deleted from the system for performing monitoring and control functions as desired by a particular operator. Conveniently, a video display unit provides alphanumeric display information to the operator regarding both the monitored and controlled functions of the combine machine as well as instructional messages for purposes of calibrating the monitoring and control system for operation with a particular combine. Moreover, the operator may select for a display in alphanumeric form suitable instructional information regarding any malfunctions of the combine and counter during operation and instructions for the correction thereof.