초록 ▼

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 cy

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 in 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. A first return from a reference reflector disposed in the path of the sonic signals to the surface of the liquid in the channel is utilized in the echolocation system to provide signals for controlling the frequency of the pulses from which the level measurements are obtained. The echolocation system is operative to provide the sonic signals in a burst during a preset interval of time at the beginning of each transmission cycle and to recognize a return as a true return after the same number of signals as was transmitted are detected during a like period of time upon reception. The transmission cycles are repeated each time a sequence of pulses corresponding to the maximum predetermined level is generated, such that the transmission cycles and the measurements are repeated continuously.

대표청구항 ▼

A system for the continuous monitoring of a region which can contain varying amounts of material and for making measurements of the amount of material therein, said system comprising means for continuously generating repetitive pulses having a frequency such that a certain number of said pulses is g

A system for the continuous monitoring of a region which can contain varying amounts of material and for making measurements of the amount of material therein, said system comprising means for continuously generating repetitive pulses having a frequency such that a certain number of said pulses is generated during the period in which sound travels a distance equal to the height of said region when containing an amount of said material which fills said region to a predetermined maximum height, echo sounding means for the transmission of sonic signals into said region, from a fixed distance from said predetermined maximum height, repetitively after the generation of a sequence of said pulses equal to said certain number of Said pulses and thereafter receiving return signals due to the reflection of the transmitted sonic signals from the surface of said material in said region, and means for providing said measurements responsive to the number of said pulses generated by said generating means after each said transmission until the reception of said return signals except during the period, commencing from the time of said transmission, for said sonic signals to travel twice said fixed distance above said predetermined maximum height from which said sonic signals are transmitted.