Origin of Metal Tube Rotameter
It works on the law of variable area – the fluid in metal tube upraised a float in taper tube, which increases the area of fluid passage. The float moves up in proportion to fluid flow rate and get stable when the float weight is balanced through upward hydraulic force. With a magnetic coupling, the movement of inner float by a series of counter weight and linkages. The tube as well as the float unit determines the rate of flow.
Digital Meter: High sensitive sensor for magnetic field detection is there to find out the inner float magnetic field. It enables us to display the digital read out. As it operates on battery, this flow-meter does not involve any electrical connection. It has built-in two wire transmitter that provides 24 VDC and take 4-20 mA signal.
Advantages of Digital Variable Area Flow Meters:
- Local indication without the auxiliary power requirement
- Minimal loss of pressure
- Easy to read
- Suited for low flow (8LPH)
- Accurate measuring, even at higher flow (150 m3/hr)
- Assembly with no movement, reducing the maintenance
- Default built-in transmitter of 4 to 20 mA, Loop-powered
Technical Specification :
| Accuracy | +/- 1.5% of FSR. |
| Range ability | 10:1 |
| Repeatability | +/- 0.25% of FSR |
| Temperature Rating | -50 to 120 °C. |
| Pressure Rating | 80 kg/cm2 |
| Flow Direction | Bottom to Top |
| End connection | Flanged to suit customer’s requirement. |
| Wetted Part | To suitable specific liquid or gases. |
| Mounting position | Vertical. |
| Indication | Digital flow rate |
| Transmission | 2 wire loop powered |
| Enclosure | Flameproof / Weatherproof. |
| Power supply | 9 VDC Battery |
Maximum Flow And Pressure Loss
| LINE SIZE | 20oC WATER FLOW | 0oC 1 atm AIR FLOW | APPROX PRESSURE LOSS |
| NB | m3/hr | Nm3/hr L | MM WC |
| 15 | 0.2 – 1.2 | 6 – 35 | 200 – 225 |
| 20 | 0.4 – 2.0 | 8 – 60 | 220 – 230 |
| 25 | 1-5 | 30 – 150 | 200 – 270 |
| 40 | 2.5 – 10 | 70 – 300 | 200 – 250 |
| 50 | 3.5 – 17 | 100 – 500 | 225 – 280 |
