Symptoms:
- The flow meter reading is erratic or significantly deviates from the expected flow rate.
- The flow meter shows zero flow when there is actual flow in the pipe.
- The displayed flow rate fluctuates rapidly.
Ok, as i see the picture, i suppose that you’re talking about a Promag. So, many causes here:
- someone has initiated an “Empty calibration” with a non-empty pipe. You have to do that first. Make sure that the pipe is really empty; the flowmeter has 4 detectors inside. No one must touch the water. And start the calibration.
- Because, if your “empty cal” is made with water of something else (conductive) whenever there is a flow, the Promag only see 0.
- Make sure the fluid passing inside is conductive, depending on your model, you must be > 100µS
- Make sure the probes (inside the flow meter) in contact with water are clean.
- Activate the Detection of Product. in French: DPP. Don’t know the real term in English menus. When this function is activated, if your pipe goes empty or small level of fluid inside. The calculator force 0 on the display. So your flowmeter won’t fluctuate randomly.
Something else, I hope that your pipes are conductive (metal…) and linked to the ground. If not (plastic, fiber or PVC pipes.) you’ll need a circular ground plate to install between your flowmeter and the pipe. To create the electrical loop. Without that, no measure or random values.
Insufficient upstream straight pipe section: Typically requires ≥10D, where D is the pipe diameter. Solution: Ensure the installation location has sufficient straight pipe sections. Incorrect electromagnetic flowmeter installation orientation: Should be installed horizontally or vertically. For vertical installation, fluid should flow from bottom to top. Solution: Reinstall to ensure correct orientation. Electromagnetic flowmeter requires full pipe measurement: Partial pipe filling causes measurement errors. Solution: Ensure full pipe flow; install air vent valves if necessary. Electromagnetic flowmeter conductivity requirements not met: Only suitable for liquids with conductivity ≥5 μS/cm. Solution: Select a flowmeter suitable for low-conductivity liquids or change the medium. Medium contains gas or solid particles: Affects measurement signals. Solution: Install air vents or filters to ensure medium purity. Poor electromagnetic flowmeter grounding: Causes signal interference. Solution: Inspect grounding system to ensure proper grounding. Power voltage fluctuations: Affect normal flowmeter operation. Solution: Use a regulated power supply to ensure stable voltage. Loose or damaged cable connections: Cause unstable signal transmission. Solution: Inspect cable connections and replace cables if necessary. By inspecting installation, medium, electrical connections, parameter settings, and equipment status, along with regular calibration, measurement inaccuracies can be effectively resolved to ensure measurement precision and long-term stable operation.
