Electromagnetic Flow Meter — BF40
BF40 electromagnetic flow meter is a continuously upgraded high-precision, high-reliability product at the international level in excitation, lining and intelligence technology. It measures the volumetric flow of conductive liquids — acids, alkalis, salts, slurries, pulp and waste water — with no moving parts, no pressure loss and high corrosion resistance. In integral or remote design; flanged, wafer, hygienic or insertion.
Specifications
| Accuracy | ±0.5 (special ±0.25) |
| Repeatability | 0.2 (special 0.1) |
| Fluid conductivity | >5 μS/cm (special 3 μS/cm) |
| Velocity range | 0.3 – 15 m/s |
| Ambient temperature | -20 to +60 °C |
| Ambient humidity | 5 – 95% RH (non-condensing) |
| Power supply | 80 – 264 VAC / 24 VDC / battery |
| Protection | IP65 / IP67 / IP68 |
| Ex rating | Ex d II BT4 |
| Output | 4–20mA, pulse/frequency, RS232C/RS485, BRAIN, HART, MODBUS |
| Bi-directional | Yes (measurement & totalizing) |
Details
Working Principle
Faraday's law of electromagnetic induction: when a conductive liquid cuts magnetic field lines it induces a voltage E = k·B·D·v, proportional to the average velocity and hence volumetric flow. The signal is picked up by two electrodes in contact with the liquid, amplified and converted to a unified output. A minimum liquid conductivity is required.
Key Features
- Dual-chamber housing separates electronics from the terminal block
- Ultra-low-EMI switching power supply, wide voltage range
- High-definition backlit wide-temperature LCD
- RS232C, RS485, BRAIN, HART, MODBUS bus communications
- Bidirectional flow measurement and totalization; fast response, good stability
- Liner options: natural/hard rubber (acid-alkali-salt), neoprene, polyurethane, PTFE, PFA
- Electrode options: Mo-bearing stainless, Hastelloy B/C, titanium, tantalum, platinum
Liner selection
| Liner | Features | Application |
|---|---|---|
| Natural (soft) rubber | Elastic, wear-resistant; weak acid/alkali only | <80 °C water, sewage |
| Acid-resistant (hard) rubber | Resists HCl, acetic, oxalic, ammonia, phosphoric, 50% H2SO4, NaOH/KOH | -25~+90 °C acid-alkali-salt |
| Neoprene | Excellent elasticity, wear; dilute acid-alkali-salt | <80 °C water, sewage, slurry, ore pulp |
| Polyurethane | Excellent wear resistance; poor acid/alkali | <70 °C coal slurry, sludge, ore pulp |
| PTFE | Boiling acids, alkalis, aqua regia, organics | -80~+120 °C concentrated acid/alkali, hygienic; not for KOH, HNO3, HF |
| PFA | Like PTFE, better bonding/strength/heat | -80~+160 °C concentrated acid/alkali, hygienic; not for KOH, HNO3, HF |