How to calibrate a single-flange differential pressure level gauge
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The on-site tank is equipped with two level gauges: one magnetic flap type and one differential pressure type. Currently, the readings from the differential pressure level gauge do not match those of the magnetic flap type gauge. The differential pressure level gauge uses the unit ‘M’, and its range is set according to the height of the storage tank. What should be done to adjust it?
I couldn’t understand these two photos of yours. Is the transmitter built into the magnetic flap? If it’s not a single-flange differential pressure transmitter as mentioned in your title, then it must be an open-container, atmospheric-pressure device. In that case, close the valve at the base of the transmitter, loosen the bolts connecting the transmitter to that valve so that the transmitter’s diaphragm is exposed to the atmosphere, and then adjust the zero point. The pressure is calculated based on the height of the medium at full scale and the density of the medium. Usually, once the zero point is adjusted, your problem will be solved
Differential pressure is converted into height through pressure, involving the issue of density values.
Judging from the diagram, this appears to be a single-flange level transmitter for open containers. Measuring the level requires taking the density of the fluid into account; for example, in a 10-meter tank, even a slight difference in density can result in significant errors, and it’s necessary to recalculate the pressure value. Our smart transmitters, on the other hand, allow for direct adjustment of the density
This single-flange level gauge requires adjustments to the medium density and range settings in order to be calibrated; it’s not very reliable. We had one of these as well – the zero point was set, and when the liquid level was stationary, the readings matched according to the medium density. However, as the liquid level changed, the discrepancy between the readings and those on the magnetic flip switches gradually increased, and this problem could not be resolved. In the end, we switched to the Chuanyi EJA gauge.
The range of your gauge is not set arbitrarily; it should be determined by dividing the actual pressure range of the gauge by its density. Otherwise, if it’s set to 10,000 meters, wouldn’t it be possible to measure the Mariana Trench?
The factory default range indicated on the label of this manufacturer’s device is 0-5M, with M as the unit of measurement; the level measured by it is not accurate at all compared to the actual level
Correct! Differential pressure is a matter of density; if the calculation is inaccurate, it can be recalculated using the magnetic flap. Also, will the composition change? Nowadays, single-flange media tanks are rarely used, as it’s uncommon to have direct exposure to the atmosphere
Measure whether the open tank, the installation port of the single-flange differential pressure transmitter, and the lower flange of the magnetic flap level gauge are at the same height.