Problems with the use of reed switch level gauges
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The reed switch level gauge currently in use in one of the waste containers causes the reading to drop directly to -1% once the liquid level exceeds 102%. Based on the principle of reed switches, what is the reason for this phenomenon? ? ?
How can it be 102%? If the float exceeds its range, it will stay at the full-scale position all the time
It will exceed the range, but I don’t know why it becomes negative
I’m not sure if your level gauge is smart; some smart instruments come equipped with an over-range protection feature that forces a minimum output once the signal exceeds the specified range.
This is not a negative value; it means the reading has returned to zero. The float switch has exceeded its range, and the reed switch is no longer activated. -1% is an illusion – it should be 0%
What causes it to become 0 when it exceeds the range? Manually set? Is it still the principle at work?
A reed switch is just a small tube. Once your float rises above the reed switch at 100%, all the reed switches become disconnected. The instrument naturally assumes that this is a negative liquid level. The solution is to install a limit ring at the 100% liquid level, so that the float can’t rise any further.
What the people upstairs said is all correct. Personally, I think that when a reed switch is knocked over and it shows -1%, it’s very likely that the default values were used for the settings related to out-of-range conditions in the system configuration; or perhaps batch point creation was used during configuration, and those settings weren’t changed afterward. This is my personal opinion for reference only.