Georg Fischer 59301.296 3-2537-6C-PO 0.5"-4" Signet 2537 Paddlewheel Flowmeter, Polypropylene Black PVDF Titanium FPM. The Signet 2537 Flowmeter is the next generation in fluid measurement technology from the inventor of the original paddlewheel flowmeter. This sensor is an improvement on what’s already an industry standard. It has the added functionality of various output options including flow switch, multi-functional pulse, digital (S3 L) or 4 to 20 mA. Additionally, it offers low flow, low power and high resolution and can be configured onsite directly through the built-in user interface.