Ultrasonic Level Switch SUU-011
Ultrasonic level switch SUU-011 is designed for installation in a variety of stationary and mobile sites in industrial and other conditions to be used in alarm systems of technological and emergency levels of liquids, automatic process control systems, pumps, systems of protection against dry running, in systems detecting the presence of liquid in the premises.
The device can be used indoors and outdoors over a wide range of climatic conditions. The device has no moving parts, is shock and vibration resistant, and do not require adjusting during operation. The device is applicable both for conventional and hazardous installations and facilities in accordance with the regulatory and technical documents regulating the use of electrical equipment in hazardous areas.
Operating conditions of the device:
- ambient temperature of the electronics unit – from -40 to 70°С;
- ambient temperature of the sensor – from – 40 to 125°С;
- the pressure in the installation reservoir of device – up to 6.4 MPa.
The level of protection against dust and moisture – IP67.
The device is structurally made based on dust and moisture-proof, explosion-proof housing, which is connected to the extension rod, piezoelectric sensor with emitter-receiver, and reflector. To feed external signals, the device unit has a sealed cable gland. The electronics unit circuit board with terminal blocks for connecting cable conductors of external signals is arranged under the housing cover.
The operating principle of the device is based on the differences in the speed of propagation of acoustic waves in gaseous and liquid media. The electronics unit, which is a microprocessor device generates a probing pulse supplied to the piezoelectric element which converts an electric pulse to the ultrasound. In the absence of liquid in the sensor arrangement area, ultrasonic vibrations are damped in the gas (air) medium.
In the presence of liquid, the probing ultrasonic pulse is reflected from the bottom of the reflector, through the estimated time goes to the piezoelectric element, is converted into an electrical signal to be analyzed by electronics unit. This procedure helps to uniquely and precisely determine liquid reaching the level of sensor location.
At the same time the microprocessor generates the appropriate signal: command on the closing (opening) the relay contacts in the device complete with relay output or implements change in the current value in the current loop if the device is complete with current output.