Abstract: A system for the automatic measurement of the level, flow rate, and flow volume of liquid flowing through a channel is described. An echolocation system operates to detect returns from the surface of the liquid in the channel during successive transmission cycles in response to the reflection of sonic signals. A source of pulses having a frequency which provides a certain number of pulses corresponding to the travel time of the sonic signals over a distance equal to a maximum predetermined level or head of the liquid in the channel provides pulses from which the liquid level, flow rate, and flow volume can be obtained. The control of the frequency of the pulses from which the measurements are obtained may be accomplished by a digital phase locked loop system to minimize the effects of changes in ambient condition, such as temperature, vapor pressure, and composition of atmosphere as often occurs in such conduits.

Abstract: A circuit providing a ramp signal having dual slopes of increasing and decreasing magnitude is controlled to provide one of its ramp portions with a slope which varies in accordance with a signal perturbing effect and the other of which is constant. The dual slope ramp duration is modified in proportion to the perturbing effect and is used to compensate therefor.

Abstract: A system for controlling operations of a process or of another system or apparatus which must perform its operations in precise time sequence. The control system also initiates the performance of successive cycles of such sequences of operations with the same precision of timing as the operations themselves. A timing generator which operates from or includes a constant frequency source produces pulses of constant periodicity which time the operations so that they occur in selected time sequence during each cycle, starting when a cycle is initiated. The timing of the operations and their duration may be preset for the process, apparatus or system to be controlled. A large timing range is provided to meet the needs of the particular process system or apparatus and to make adjustments as may be required in the field. The cycles of operation sequences may be selected in accordance with the mode of operation desired.

Abstract: A system for the automatic measurement of the level, of material in a container and especially of liquid flowing through a channel is described. An echolocation system operates to detect returns of reflected sonic signals from the surface of the liquid in the channel during successive transmission cycles. A source of pulses is provided having a frequency which provides a certain number of pulses corresponding to the travel time of the sonic signals over a distance equal to a maximum predetermined level or head of the liquid in the channel. The time interval between signal transmission and reception is excess of twice the time for travel of the signals between the transmitter and the maximum level of liquid is a measurement of the liquid level in the channel.

Abstract: To measure liquid flow through channels with various cross sections, detectors of liquid level and velocity are placed in proximity to the liquid to measure flow in terms of the product of the cross sectional area of the fluid and its velocity. Adjustable switches are employed to provide input signals to the computation circuitry which are constants while the detectors provide the data signals which result from the dynamic measurements.

Abstract: In order to enable measurement of liquid flow through channels noninvasively without contact or interference with the flow through the channel, detectors of liquid level and velocity through the channel are installed above and below the channel and transmit and receive only ultrasonic signals. A flow measuring system is operated by their detectors and measures flow in terms of the product of the area through which the liquid flows and its velocity.