How should the differential pressure range be calculated for the differential pressure level gauge w

The differential pressure level transmitter is mounted at the bottom of the liquid container and reflects the level height by means of a gauge pressure signal. This kind of differential pressure instrument includes pneumatic, electric differential pressure transmitter and flange liquid level transmitter, which is easy to install, easy to realize remote transmission and automatic adjustment, and is widely used in industry. In the process of level measurement and control in the pharmaceutical, food and chemical industries, the container containing the liquid often works under pressure, and the conventional hydrostatic level transmitter cannot meet the measurement requirements.

The differential pressure level gauge has two pressure ports: gas phase and liquid phase. The pressure at the gas phase pressure point is the gas phase pressure in the equipment; In addition to the pressure of the gas phase, the pressure at the pressure point of the liquid phase is also affected by the static pressure of the liquid column, and the difference between the pressure of the liquid phase and the gas phase is the static pressure generated by the liquid column. When one end of the differential pressure gauge is connected to the liquid phase and the other end is connected to the gas phase, according to the principle of hydrostatics, there are:

pb=pa+hρg （1）；where: h - liquid height; Density of the medium to be measured; g – the acceleration of gravity at the measured location.

From Eq. (1), we get: δp= pb pa= h g ; In general, the density and gravitational acceleration of the measured medium are known, so the differential pressure measured by the differential pressure gauge is proportional to the height h of the liquid, so that the problem of measuring the height of the liquid becomes the problem of measuring the differential pressure.

The above is the specific and working principle, generally the installation of differential pressure level gauge to have two contacts, measuring two pressures, therefore, the capillary with silicone oil you said does not seem to affect the differential pressure range. But please tell me the parameters of your differential pressure level gauge first.

A column of water with an atmospheric pressure of 10 meters, just 2 meters, the range is 0

According to the published f=PGH density and g, it is known that the pressure on the high and low pressure sides can be calculated by simply measuring the height.

According to the density of the liquid being measured.

The highest and lowest height of the liquid level.

Calculation: The maximum pressure p+ in the positive pressure chamber

The maximum pressure of the negative pressure chamber is p-

The measuring range of the differential pressure level gauge is p- p+

The range is δp=p+p-

According to the density of the liquid being measured.

The highest and lowest height of the liquid level.

Calculation: The maximum pressure p+ in the positive pressure chamber

The maximum pressure of the negative pressure chamber is p-

The measuring range of the differential pressure level gauge is p- p+

The range is δp=p+p-

Empty the jar and output it with a zero value; Fill the jar again, take a full value output, and it should solve the problem.

If it is to measure condensate and vapor-liquid mixture, it has a lot to do with the way of installation.

If it is full scale, it means that the differential pressure range is selected incorrectly, or the measurement situation is really overloaded. Then there is the damage to the meter, and the received signal is not the output value of the normal meter.

Changsha Delu Electromechanical provides you with IGEMA level gauges imported from Germany, including electrical contacts, red and green two-color, magnetic flap and other ......

The actual measured level is calculated from the measured differential pressure, and h=p g is obtained according to the pressure formula about p = gh

If the transmitter is fine, the positive pressure pipe is not blocked, and the actual liquid level is higher than the measured liquid level, so it may be that the density is selected to be larger when calculating the range, resulting in the transmitter being selected when setting the range, and the solution is to choose a larger solution: recalculate the range according to the density, and there is another reason for correcting the range of the pressure transmitter, if it is a double flange differential pressure level gauge, and it is installed in a pressure vessel (or a sealed container and the pressure on the negative pressure side is unstable), theoretically the differential pressure transmitter can be accurately measured, but it cannot be measured or the measurement is inaccurate in actual use, This kind of site is very common in actual production, as for the reason, you must know that it can be solved, there are many manufacturers on the site specializing in the production of liquid level instruments (such as external vibrating level gauges) for container level measurement that cannot actually use double flange differential pressure liquid level transmitters.

The difference in pressure level gauge with capillary tube has a limit to measure the height of the gauge and it is not possible to exceed it, mainly because the weight of the isolation liquid brought by the height difference between the two flanges makes the pressure of the level gauge sensor exceed the range of the range, and you can consult the manufacturer for details.

The effects of a small amount of gas or some components in the capillary at negative pressure can be amplified, such as water turning into water vapor under negative pressure, which can only be avoided or mitigated by a truly high-quality transmitter.

Double flange level gauge migration calculation to know the specific gravity of silicone oil. In fact, after the installation is completed, before feeding, the zero position can be calibrated by means of a migration or zeroing mechanism.

The differential pressure level gauge model composition should include the following parts:

Output signal. Measuring range.

The material of the wetted part (sensor cassette material and body material).

Flange Standard Flange size The material of the flange.

Capillary length and the type of injected fluid (silicone, high-temperature, fluorine, or glycol) in the capillary electrical terminal size.

Displays the header type.

Installation methods and other installation accessories, etc.

The opinions of technical sales personnel in the differential pressure level gauge industry, I hope it will be helpful to you!

Output signal, communication protocol, range, sensor material, flange size, pressure level, temperature, etc.

What are the components of the hydrostatic level gauge and the submersible level gauge?

The liquid above has pressure on the bottom, so the higher the tank level, the greater the static pressure of the liquid below.

There is a relationship between the pressure (differential pressure) signal obtained by the differential pressure level gauge and the liquid level: p=h· ·g.

where: p-differential pressure; h-level, -medium density, g-local gravitational acceleration According to the above formula: After calculating and selecting the differential pressure measurement range (range) of the appropriate differential pressure level gauge, the output of the transmitter can be directly related to the liquid level. See.

The range should be 4, and the migration volume is 3775mmH2O