Problems with the EJA100A differential pressure level transmitter
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Site conditions: An EJA100A differential pressure transmitter with a range of 0–2000 mm H2O, along with a balanced-tank type level gauge, used to measure the level in the deaerator. After draining the water from the deaerator, the gauge reading should indicate around 0%. However, the current situation is the opposite: the transmitter gauge shows nearly 100% of the scale, and the DCS indicates almost full capacity. It seems like the range is reversed. What’s the problem? I don’t know how to solve it; I can’t figure out a way to address it. Seeking help from experts.
It is likely that there was a shift in your transmitter; after draining it, the condensate or isolation fluid was also emptied.
The condensate has not been drained; it was confirmed that there is condensate present. Are you saying I still need to drain the condensate? It shouldn’t be necessary, right? At the current situation, after the deaerator is vented, the differential pressure is at its highest; the highest differential pressure corresponds to the highest liquid level. How can we ensure that the highest differential pressure corresponds to the lowest liquid level? . .
You say that the condensate is still present, so it’s hard to say what’s going on. I would like to ask whether this unit was newly installed or has been in use normally. If it has been in normal use and this issue occurs, it might be due to a fault with the transmitter or a loss of water in the standard water column. For those that have been newly installed, recalibrate the transmitter and see.
In a two-chamber balance container used for measuring liquid levels, the negative pressure chamber must be filled with water. The transmitter exhibits 100% negative drift; if the negative pressure chamber is not filled with water, the reading will be too high. If a negative value appears, it indicates incorrect drift.
Water in the negative pressure chamber has leaked; it needs to be refilled.
The positive and negative pressure chambers of a balanced container-type level gauge are the opposite of those in a conventional differential pressure transmitter.
Look at this diagram; this is called \"direct connection with reverse measurement\" – the meter is connected in a direct manner, while the level is measured in reverse. The higher the water level in the boiler drum, the lower the pressure difference. Swap the voltage difference values corresponding to 4mA and 20mA; that should work. .
Learned*:):handshake