Questions regarding double-flange level measurement
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What are the requirements for two different media when using double-flange level gauges?； Is the liquid level height a constant value? ； Why not require a higher standard than that of the flange surface on the negative pressure side?
The liquid level height cannot be a fixed value; what is the point of performing fixed-value measurements then? It must not be higher than the flange surface on the negative pressure side; otherwise, the reading will be at its maximum and it will be impossible to make a determination.
As long as the medium does not corrode the flange diaphragm； Is it still necessary to measure if the liquid level height is a fixed value? ； The liquid level cannot be higher than the flange surface on the negative pressure side; otherwise, the liquid level cannot be measured.
Does using dual-flange transducers to measure dielectric constants require two dual-flange units? How to measure the dielectric constant? Those who know, please tell me
The image above is a bit tricky; let’s be lazy and just imagine it. ΔP (min) = (ρ_upper – ρ0)gH; ΔP (max) = (ρ_lower – ρ0)gH. Therefore, the range of the transmitter is (ρ_lower – ρ_upper)gH, which is generally quite small. Here, ρ0 is the density of the capillary filling liquid. Medium requirements: A greater density difference is more conducive to the proper operation of the transmitter ； Height requirement: The liquid must be above the upper flange; otherwise, ΔP will not be within the specified range.
The liquid level must be above the upper flange; otherwise, both the liquid level and the interface level will change. When both variables change simultaneously, it becomes impossible to measure them
It is required that, whether it is a light medium or a heavy medium, it must always remain above the negative pressure tap. Because we set the pressure difference when completely filled with a light medium to zero, and the pressure difference when completely filled with a heavy medium to the full scale; this is on the premise that the container is fully filled, as only then can the interface be detected.
Reply to 1# akzonobel002: Generally, a double-flange setup is used to measure the interface; it’s best if the densities of the two fluids are not too similar. There aren’t many other requirements.
As long as the two media do not corrode the diaphragm box of the flange, it is acceptable. If the gauge is installed in a location outside the negative pressure chamber, measurement will not be possible; it should be placed between the two flanges or below the positive pressure chamber. The measurement distance can be whatever is appropriate, as long as the upper and lower limits are set properly