We are observing a confusing problem in our magnetic flowmeter. It's a Siemens mag 5000 series 15DN used in acid service installed in a PVC line. Actually when we open control valve in downstream, the flow suddenly comes to some blue (little close to actual value) but value gradually start coming down.
Like 230 l\hr...228....227...220.....215...210
although we have verified that actual flow is not going down.
Please do you have any idea what's wrong with magmeter, its so solution.