Level gauge issue
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I have an EJAA118W level gauge. It was purchased for use at a liquid level of 6 meters, but due to changes in operating conditions, it is now used at a level of 1 meter. However, some problems have arisen: right after it was installed, the reading was -5%, and after performing the calibration, it returned to -5% after one or two days. Now the tank is filled with water, yet the reading is still 110%. I’m not sure what the problem is; I would appreciate advice from those with experience in this area
First, confirm that the table is in good condition, including the diaphragm； Then verify whether the process pressures of the two tanks are exactly the same; if not, check whether corresponding adjustments have been made to the range settings ； Next, is your migration volume calculated, or is it determined through actual measurement? ； If it is calculated, it may differ from the actual situation. If the conditions are met, actual calibration is still the most accurate. Ultimately, it really doesn’t matter whether it shows -5% or 110% ； The key is to work together with the process engineers to confirm the 0% and 100% points of the liquid level.
Has the range been changed? Is the density of the medium under operation selected correctly? You can first perform a zero adjustment with no load, and then determine the instrument’s range based on that density; if that doesn’t work, you might suspect there is a problem with the instrument, haha!
The instrument is confirmed to be in good condition, as it has been installed for over a year now without any use – it has always remained an empty tank. There is no process pressure or anything of the kind; currently it is only being used for testing, with water being pumped through it. In other words, it is being used at atmospheric pressure. I carried out the calibration using BT200, via automatic calibration, and the range was adjusted accordingly; the density value was set based on that of water
Once it is confirmed that the instrument is in good condition, adjustments are made using BT200 for its upper and lower range shifts. Use BT200 to change its output format so that it displays in meters directly.
Once it is confirmed that the instrument is in good condition, adjustments are made using BT200 for its upper and lower range shifts. Use BT200 to change its output format so that it displays in meters directly.
1. If the transmitter can be removed, first test it; if it is in good condition, then consider the issue of relocation. 2. What type of silicone oil is used in the capillary tube of the transmitter? Different silicone oils have different densities, and as a result, the value of negative migration also varies. 3. If the transmitter does not indicate 110%, it does not necessarily mean that the transmitter is damaged; it could be that the set parameters do not match the actual conditions. 4. The double-flange transmitters of EJA sometimes become unreliable after too many online migrations. Remove it from the device, test it again, and then reinstall it – that way it will work properly. We have encountered this issue before, but the exact cause remains unknown at present. 5. If your transmitter uses type B silicone oil, then the density of that silicone oil is 0.94, while the density of water is taken as 1. For a measurement range of 1 meter, the set range for your transmitter will be: -9.212~0.588 KPa. You may try this out; it’s for reference only.
It’s possible there’s an issue with the range
This situation is caused by problems with the range and drift settings. Changing the range from 6 meters to 1 meter means changing it from 0–60 KPa to 0–10 KPa ； Attention should also be paid to the installation location of the transmitter and the density of the medium, after which the migration amount is calculated; there are calculation methods available upstairs.