Can the pressure transmitter be replaced with a level gauge?
Thread Content
The tank is 15 meters tall, the pressure transmitter is located at a height of 1 meter, and the density of the liquid is 0.85. How should the range of the pressure gauge be adjusted?
Pressure = density x height x 9.81
In a sealed container, a pressure transmitter cannot be used to measure the liquid level; then why isn’t a level transmitter used?
In a sealed container, a pressure transmitter cannot be used to measure the liquid level; then why isn’t a level transmitter used?
This post was last edited by jujiangliu on 2017-12-5 07:19. It’s a network issue; I tried clicking several times.
When considering this issue, you need to keep these points in mind: first, if you say that the pressure transmitter is installed at a distance of around 1 meter, then this 1 meter should be taken into account; second, since the tank is 15 meters high, does that mean that the full scale corresponds to a height of 15 meters as well? This isn’t real; some margin needs to be left. Also, is this container sealed or open to the atmosphere? Lastly, what type of pressure transmitter do you have? If it’s capillary or differential type, adjustments may be necessary depending on the installation location. . . .
The range is determined by performing calculations using the hydrostatic pressure formula hρg and applying a certain safety factor, such as a factor of 1.1 or 1.2.
First, it must be open, that is, the liquid level must be in communication with the atmosphere in order to use a static pressure transducer for level measurement; otherwise, only differential pressure can be used. Second, when the pressure transducer is located at a depth of 1 meter, a 1-meter blind zone cannot be eliminated. If this position is taken as the zero level of the liquid surface, the highest actual liquid level (i.e., the range of the liquid level) is 14 meters. At the liquid level zero position, the pressure transmitter outputs 4mA. Third, the range of the pressure transmitter is not specified. The pressure generated by that liquid with a density of 0.85 at 14 meters is 0.119 MPa; by dividing the range of the pressure transmitter by 0.119 MPa, a ratio can be obtained, which can then be used in the pressure gauge. Fourth, it should be noted that if the range of the pressure transmitter differs significantly from 0.119 MPa, the accuracy cannot be guaranteed, and the pressure transmitter needs to be replaced. Fifth, for specific instructions on how to proceed, please feel free to contact us. We mainly produce safety barriers, and we hope to meet more professionals in this field.