Which instrument is more accurate, the servo one or the differential pressure one? ?
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Are the ball tank level gauges here servo-controlled with a pressure difference? But I feel it’s not very accurate, off by 1 to 2 meters compared to the on-site level gauge.
The servo should be more accurate; the differential pressure is affected by density.
Thank you. Thank you for sharing!
Servo is accurate. Especially Enlav’s. It claims to have an absolute error of within 1 mm.
1~2 meters? It’s not just a matter of accuracy, right?
Servo systems require high precision, while differential pressure meters generally have a relatively narrow measurement range. Within this limited range, the measurement accuracy of such instruments isn’t that much worse; however, differential pressure measurements are affected by density.
Servo systems have higher precision than differential pressure systems; from a measurement principle perspective, servo systems are only related to the interface. The differential pressure is closely related to the density of the medium being measured, and the density changes significantly with temperature as well.
Where is there any need for pressure difference these days? I’m using the E+H Servo Proservo NMS5x series, which works very well; it’s also used for high-level interlocks in spherical tank areas, and the error level can’t be that high. Are you measuring liquefied gas or something else? If there are significant changes in density or if a two-phase gas-liquid state exists, errors are bound to occur. You can ask the process team to install a local level gauge (is it a glass plate type or a magnetic float type?) ) Make the comparison when the inlet and outlet liquid levels are stable; it is not appropriate to do so during feeding or discharging.
The servo should be more accurate; the differential pressure is affected by density.
Servo level gauges are more precise, as when driven by a magnetic drum, the smallest unit of rotation that controls them is a grid; in other words, they operate based on signals from these grids. One raster grid is exactly equal to one scale (I forgot, what a sin! ). Our spherical tanks use servos to calibrate the radar level gauges installed nearby.