
Ultrasonic Level Transmitters

Level control and measurement in industrial processes is essential to optimize performance and avoid potential problems. Level measurement determines the position of a liquid relative to the top or bottom of a container. Levels that are too high can cause overflow, resulting in safety or environmental problems, while levels that are too low can cause damage to equipment. Fluid level control devices monitor, compare and regulate liquid levels within a process to a set value.
Ultrasonic transmitters operate by sending a sound wave generated from a piezoelectric transducer to the surface of the material being measured. The transmitter measures the length of time it takes for the reflected sound wave to return to the transducer. The benefit of through-air measurement technologies, such as ultrasound measurement, is that the measuring device never comes in contact with the product being measured.
Dwyer Mercoid Series ULT Ultrasonic Level Transmitters provide accurate, reliable, non-contact measurement of liquid levels. Mapping software makes the effective measure surface only a 3 inch diameter column, so there are no concerns with ladders, pipes or other tank obstructions in the sound cone.
APG Ultrasonic Level Transmitters are designed for level applications that range from 4 inches to 50 feet. They are field programmable and have automatic temperature compensation built in to each model.
Products
Some of the most common types of transmitters and transducers can be found on pressure instruments. Examples of these include: drop-in well pressure devices and devices that measure the pressure in a pipe or gas chamber. Transmitters and transducers can also be found on flow and speed measurement devices.
What is the difference between transmitters and transducers? The main difference is the way they send data to the monitoring device, like a PLC. In terms of measurement, the transmitter will reference a measuring unit by sending a milliamp signal (such as 4-20 mA). A transducer will reference a measuring unit by sending a voltage signal, typically in volts or millivolts.
Why have the two different types of transmission methods? The method will depend on the application. If the electrical connection in the application travels a short distance, a pressure transducer is the better choice. Pressure transducers are smaller with fewer active electronic components that can be upset by electromagnetic interference. Also, the voltage signals transmitted over longer distances are subject to voltage drop and signal corruption. A transmitter is better for transmitting signals over a long distance.