- Aug 07, 2017 -
Capacitive level transmitter for industrial enterprises in the production process to measure and control the production process, the transmitter is mainly used for conductive and non-conductive media liquid level or powdery solid material level of long-range continuous measurement and Instructions.
Capacitive level transmitter by the capacitive sensor and electronic module circuit, which is a two-wire 4 ~ 20mA constant current output for the base type, after conversion, you can use three or four lines of output, the output signal is formed as 1 ~ 5V, 0 ~ 5V, 0 ~ 10mA and other standard signals. The capacitive sensor consists of an insulating electrode and a cylindrical metal container with a measuring medium. When the material level rises, because the dielectric constant of the non-conductive material is significantly smaller than the dielectric constant of the air, the capacitance changes with the material height. The transmitter module circuit consists of a reference source, pulse width modulation, conversion, constant current amplification, feedback and current limiting. The advantages of using the pulse width modulation principle is the lower frequency, the surrounding meta-frequency interference, good stability, good linearity, no obvious temperature drift and so on.
Ultrasonic transmitter is divided into general ultrasonic transmitter (no head) and integrated ultrasonic transmitter two, integrated ultrasonic transmitter is more commonly used.
The integrated ultrasonic generator is composed of a head (such as an LCD display) and a probe. The transmitter, which is a direct output 4 ~ 20mA signal, is a device that integrates the miniaturized sensor (probe) and the electronic circuit Together, so that the smaller, lighter weight, the price is cheaper. Ultrasonic transmitter can be used for liquid level. Level measurement and open channel, open channel and other flow measurement, and can be used to measure the distance.