ULTRASONIC LEVEL INDICATOR Russian patent published in 2002 - IPC

FIELD: ultrasonic equipment for control over level of liquid media used in petroleum refining, chemical and other branches of industry. SUBSTANCE: ultrasonic level indicator has piezoelectric converter acoustically coupled to outer surface of wall of tank and is connected by means of connection cable to power amplifier. First detector whose output is linked to central conductor of connection cable and secondary winding of matching transformer are connected in parallel to piezoelement. Primary winding of transformer is connected through first blocking capacitor to connection cable. One end of connection cable is connected to input of second detector and via second blocking capacitor to output of power amplifier. Input of power amplifier is connected to voltage- controlled generator of continuous oscillations and frequency divider. Output of frequency divider is coupled to sawtooth voltage former and via adder to control input of voltage-controlled generator. Output of second detector is connected to one of inputs of adder-amplifier, its other input is linked to second potentiometer and its output is connected to one input of comparator. Another input of comparator is connected to third potentiometer and its output is coupled to indicator and relay unit. EFFECT: increased functional sensitivity of level indicator and expanded temperature range of controlled medium. 2 dwg