Ultrasonic continuous level measurement technology
The basic principle of level measurement using ultrasound is the assumption that the speed of sound in air remains constant with increasing temperature - 344.1 m / s at 20 ° C.
A piezoelectric crystal located in an LS type sensor body converts an electrical signal into a series of ultrasonic pulses (sound waves), which are then transmitted through the air or a pair at a predetermined speed. These signals are reflected from the surface of the fluid and return to the sensor. The crystal converts the returned back-reflected sound signal into an electrical one for further processing. The length of time between the transmitted and received echoes is proportional to the distance between the outer surface of the sensor and the surface of the liquid and inversely proportional to the height of the liquid level in the tank.
The returned reflected signal is processed by a microprocessor-based recognition circuit in order to eliminate extraneous signals and provide an opportunity for further calculation of the liquid level. This information is then converted to an analog 0-20 mA or 4-20 mA signal, which is processed to ensure the operation of the alarm system and digital indicators.
Level Commander systems use the latest advances in microprocessor-based electronics, advanced reflection processing techniques and the latest high-energy sensors to get an accuracy of +/- 0.25%. Level Commander systems have higher accuracy and do not give a shift in readings, unlike other similar devices.