Regarding Rosemount vortex flowmeters
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The unit is equipped with a Rosemount vortex flow meter with a range of 0–1600 kg/h; it is used to measure medium-pressure steam. Currently, the meter does not return to zero after the valve is closed, and it continues to show a value of over 200. When the valve is opened to increase the flow rate, the reading still rises. The manual valve and the negative wire have been checked and confirmed to be closed, but the meter still shows 200. I’ve tried adjusting the setting to 210, but it still displays 200. I would appreciate some advice from everyone.
Remove the flow meter and seal the opening (to prevent wind at the site), then check whether the flow is zero. If it is not zero, then there is a problem with the flow meter. Sometimes, when the valve is fully closed, there is a flow indication of a certain magnitude, but it is intermittent, which is caused by vibration.
Under normal circumstances, closing the valve does result in some flow reading, but this value is a bit high. I can’t disassemble it yet; if things don’t improve later, I’ll have to take it apart to check it. Thank you!
How should vortex street meters be calibrated? How should I proceed?
Is there a Hart handheld controller? Connect it and check what the frequency of the sensor output is when the value is over 200. If it remains stable at around 50 Hz, the possibility of interference from power-frequency signals is quite high.
I checked before; it’s around 59Hz. So what should be done in this case?