Common Types of Level Transmitters and How They Work

There are many types of level transmitters, including laser level transmitters, radar level transmitters, ultrasonic level meters, hydrostatic level transmitters, and float level transmitters, vibrating tuning fork switches, which are the six more common. They have their characteristics in the measurement principle and structure.

1. The lase level transmitter

The laser level transmitter is a non-contact, high-precision level transmitter with excellent performance. It works very similarly to the ultrasonic level transmitter, except that light waves are used instead of ultrasonic waves. The laser beam is so fine that it can work properly even if the liquid level is very rough. The laser level transmitters generally use near-infrared light, which uses a semi-transmissive mirror to process the laser light emitted by the optical flow.

2. The radar level meter

The radar level sensors have the same advantages as the laser measuring principle, are independent of the measuring medium, are less affected by the external environment, and do not require repeated calibration. The radar level meter 4-20ma is particularly suitable for in-tank measurement of large vessels with heated vapors, such as residual oil, asphalt, and other monitoring areas.

3. Ultrasonic level meter

The principle of an ultrasonic level transmitter is to calculate the liquid level height by monitoring the time difference between ultrasonic emission and reflection. It is simple to install and highly flexible, but easily affected by the ultrasonic propagation energy loss, and it is not suitable for wave-absorbing environments in the field of monitoring foams, dust, and vapors.

4. The hydrostatic level transmitter

The measuring principle of the hydrostatic level transmitter is to obtain the pressure value by installing a pressure transmitter at the bottom, which is calculated and converted to the liquid level height. The advantage is that it is not affected by the liquid level height. However, the higher the height, the higher the accuracy requirement of the level transmitter, when used for a long time or when replacing the liquid, it needs to be calibrated, which is widely used in the monitoring fields of urban water supply and drainage, sewage treatment, reservoirs, rivers, oceans and so on.

5. Float level transmitter

The float level transmitter measures the change of liquid level by lifting and lowering the float, which is a kind of mechanical detection, with poor repeatability, not applicable to viscous or impurity-containing liquids, and easy to cause float clogging. Float level transmitter is widely used, economical, and practical, and it is commonly used in sewage pits, fire pools, sewage treatment, and other monitoring areas, but not applicable to the food hygiene industry.

6. Tuning Fork Vibrating Level Switches

Tuning Fork Vibrating Level Switches are widely used in industrial control systems. It is suitable for almost all areas of liquid monitoring, for example, continuous level monitoring of coolant and lubricant tanks in plants. The level transmitters are equipped with reverse protection and current limiting protection circuits, so the transmitter will not be damaged when the positive and negative terminals connect in reverse during installation.