For mat-bus740 balance hood type liquid level transmitter, the sensitive device is installed at the lower end of the relay box, and the input part is the balance cover. The two are connected by the air duct (pressure guiding). The pressure of the liquid column is indirectly transmitted to the sensitive part by the air duct through the air conduction, so as to avoid the direct contact of the sensitive parts by the medium. It is not only suitable for the measurement of ordinary water, but also suitable for the liquid level measurement of high temperature, viscous, corrosive and other special occasions. It is widely used in chemical industry, metallurgy, power station, water conservancy, urban water supply and industrial wastewater.
Main technical parameters of balanced bell type liquid level transmitter
Range: 0 ~ 30 m
Measuring medium: various corrosive liquids such as water, heavy oil, crude oil, acid and alkali
Accuracy: 0.25% f · s; 0.5% f · s (generally 0.5% FS)
Output: 4 ~ 20mADC
Temperature: ambient temperature 0 ~ 60 ℃, medium temperature 0 ~ 250 ℃
Power supply: 24 VDC
Dust and moisture: All Weather
Explosion proof grade: Exia Ⅱ CT5
Indicator meter: 100% pointer meter or 31 / 2-digit LCD display (the user must specify it when ordering)
Working principle of balanced bell type liquid level transmitter
When the balance cover of the transmitter is put into a certain position in the liquid, the pressure of the sensor passing through the air duct is: P = 9.807ph + Po
Where p is the pressure felt by the sensor, in kPa
P-liquid level density, unit: g / cm3
H - height of liquid level to be measured, unit: M
Po - pressure on the liquid surface, kPa
If the back cavity of the sensor is connected with the upper part of the liquid level, then Po is zero, so h is about 0.102p/p. The pressure signal sensed by the transmitter is converted into an electrical signal, which is directly proportional to the liquid level height.
Note: the container of the liquid to be measured must be open to the atmosphere, that is, it can not be sealed, otherwise the measurement result is meaningless.