Foxboro float level gauge
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The Foxboro float level gauge experiences significant fluctuations, and it is scheduled for maintenance next month. The process requirements dictate that the entire level gauge be taken out for inspection and recalibrated. I was wondering if anyone has experience maintaining such level gauges, and what the procedures are? Please ask an expert for help
After removal, clean the buoy and float, and inspect movable parts such as the connecting rod. Verify it again using the irrigation method.
Is it the full scale after irrigation calibration, which is obtained by using ρ medium/ρ Water, multiplied by the torque after water calibration? Another issue is that the zero point of a float level gauge is not affected by buoyancy; therefore, should the zero point not be 0 newtons?
The process is correct! Indeed, buoy maintenance is quite troublesome
Disassemble and clean the float and housing, reinstall them, fill with water for calibration, and pay attention to the density under operating conditions
Is it the full scale after irrigation calibration, which is obtained by using ρ medium/ρ Water, multiplied by the torque after water calibration? Another issue is that the zero point of a float level gauge is not affected by buoyancy; therefore, should the zero point not be 0 newtons?
It is ρ_medium/ρ_water multiplied by the range value, which gives the equivalent full-liquid level for water. As for the 0N you mentioned, that is the starting point for measuring force changes during calibration; in fact, there is the greatest force when there is no liquid present, while the force is at its lowest once the container is filled. F = mg – F_float
What puzzles me now is that with the hand controller, I read an LRV of -0.99 N and a URV of 12.04 N. If the torque is highest when there is no liquid level, shouldn’t the range be reversed? I don’t understand how this works
I’m not quite sure about what you’re referring to, so I don’t dare to speak rashly. But I guess it’s a mathematical expression that we can’t figure out, rather than an intuitive way of understanding it
Thank you for your answer. I asked the technical staff at the service provider yesterday, and they said that LRV and URV refer to the buoyant force acting on the float. And negative values should not appear; it seems that the zero point of my level gauge has shifted, and it needs to be reset