The leader posed a gauge-related question; how should it be answered?
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The last edit to this post was made by liu530014416 on 2020-12-22 at 19:52. ***The level gauge used in the sulfuric acid separator is a Honeywell double-flange capillary level gauge; the distance between the centers of the upper and lower flanges is 2100 mm. The density of sulfuric acid is 1470 kg/m3, while the density of *** is 1070 kg/m3. The density of silicone oil on the negative pressure side is 930 kg/m3. Two methods are used to calculate the measurement range for the level of sulfuric acid. ////////////////////////////////////////////////////////////////////Leader’s answer: For sulfuric acid, 1470*2.1*9.8=30.25 Kpa; *** for 1070*2.1*9.8=22.02 Kpa. For silicone oil, it is 930*2.1*9.8=19.14 Kpa. 1. The range setting for the pressure transmitter should be (22.02–19.14) to (30.25–19.14) Kpa, that is, 2.88–11.11 Kpa. 2. When there is no liquid level, change the range of the pressure transmitter to 0-100 Kpa, and then perform zero adjustment. Then set the range to 22.02~30.25 Kpa. The second method is recommended. Is the leader’s answer correct?
Similarly, just plug in the corresponding values yourself.
This kind of leadership is just idle. Of course, if you can’t do the calculations, that’s another matter.
This post was last edited by c3h5e8n1 on 2020-12-21 at 14:43. The two methods are simply a result of problematic leadership. It’s a question that comes from slapping one’s own thigh. A qualified instrument technician needs to master just one effective method. Too much of it is wasteful and confuses one’s thoughts. For differential pressure level gauges, if the range of the liquid level is the same as the height of the upper and lower flanges, and it can also be confirmed that the differential pressure range corresponds linearly to the liquid level range, then it is sufficient to know the differential pressure values corresponding to 4mA and 20mA; by assuming these values and performing calculations, the differential pressure range can be determined. 4mA represents the differential pressure of sulfuric acid at the lower flange; the positive pressure side corresponds to the pressure resulting from the density of the fluid under the effect of gravity, while the negative pressure side corresponds to the pressure of pure capillary silicone oil under the effect of gravity ； 20mA represents the differential pressure of sulfuric acid at the upper flange; the positive pressure is the pressure resulting from the density of pure sulfuric acid under the effect of gravity, while the negative pressure side corresponds to the pressure exerted by pure capillary silicone oil under gravity.
Leader’s answer: Sulfuric acid – 1470*2.1*9.8=30.25 Kpa; *** 1070*2.1*9.8=22.02 Kpa. Silicone oil – 930*2.1*9.8=19.14 Kpa. 1. The range setting for the pressure transmitter should be (22.02–19.14) to (30.25–19.14) Kpa, that is, 2.88–11.11 Kpa. 2. When there is no liquid level, change the range of the pressure transmitter to 0-100 Kpa, and then perform zero adjustment. Then set the range to 22.2~30.25 Kpa. The second method is recommended. Is the leader’s answer correct?
Leader’s answer: Sulfuric acid – 1470*2.1*9.8=30.25 Kpa; *** 1070*2.1*9.8=22.02 Kpa. Silicone oil – 930*2.1*9.8=19.14 Kpa. 1. The range setting for the pressure transmitter should be (22.02–19.14) to (30.25–19.14) Kpa, that is, 2.88–11.11 Kpa. 2. When there is no liquid level, change the range of the pressure transmitter to 0-100 Kpa, and then perform zero adjustment. Then set the range to 22.2~30.25 Kpa. The second method is recommended. Is the leader’s answer correct?
Leader’s answer: Sulfuric acid – 1470*2.1*9.8=30.25 Kpa; *** 1070*2.1*9.8=22.02 Kpa. Silicone oil – 930*2.1*9.8=19.14 Kpa. 1. The range setting for the pressure transmitter should be (22.02–19.14) to (30.25–19.14) Kpa, that is, 2.88–11.11 Kpa. 2. When there is no liquid level, change the range of the pressure transmitter to 0-100 Kpa, and then perform zero adjustment. Then set the range to 22.2~30.25 Kpa. The second method is recommended. Is the leader’s answer correct?
Stop worrying about it; just say the leader’s answer is correct. The reason is simple: he is your leader.
Note that the value of g (gravity acceleration) is not constantly 9.8; it needs to be calculated based on the local atmospheric pressure at the location, otherwise there will still be errors in the range calculations
Those who can do this kind of calculation are qualified to work at pressure transmitter manufacturers; what kind of instrument work is that?