I. Product Overview
The A128 is a high-precision flow sensor based on the Hall effect. An internal impeller (containing a magnet) rotates with the fluid, and the Hall element senses changes in the magnetic field and outputs a pulse signal proportional to the flow rate. The product features fast response, high stability, and is suitable for various liquid metering and control applications.
II. Core Technical Specifications
| Project | Parameters/Features |
| Operating voltage | 5 – 24 VDC |
| Working flow range | 1 – 30 L/MIN |
| Water pressure resistance | ≤ 1.75 MPa |
| Insulation resistance | ≥ 100 MΩ |
| Output pulse duty cycle | 50% ± 10% |
| Output high level (DC5V) | > DC 4.6V |
| Output low level (DC5V) | < DC 0.5V |
| Anti-backflow characteristics | A flow rate of 10L/MIN and a frequency of <10Hz are supplied to the outlet. |
| Wiring definition and plug specifications | Plug: SM-3Y white terminal (3×160mm), cable length can be customized.
Red: Positive power supply (5-24VDC) Black: Negative power supply (GND) Yellow: Signal output (connected to host I/O port) |
| Frequency-flow relationship | F = 8.1 × Q – 3 (±10%) （F：Hz，Q：L/MIN） |
III. Frequency-Flow Characteristics Reference Table
| Flow (L/MIN) | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 |
| Reference frequency (Hz) | 13.2 | 21.3 | 29.4 | 37.5 | 45.6 | 53.7 | 61.8 | 69.9 | 78 |
| -10% Frequency (Hz) | 11.9 | 19.2 | 26.5 | 33.8 | 41 | 48.3 | 55.6 | 62.9 | 70.2 |
| +10% Frequency (Hz) | 14.5 | 23.4 | 32.3 | 41.3 | 50.2 | 59.1 | 68 | 76.9 | 85.8 |
IV. Application Areas
- Smart bathroom products:smart toilets, gas water heaters, electric water heaters, dishwashers
- Water appliances:coffee machines, water dispensers, water purifiers, water vending machines
- Smart home appliances:robot vacuum cleaners, washing machines, humidifiers
- Industry and Agriculture:Agricultural Irrigation, Water Purification Equipment, Flow Metering and Water Shortage Protection
V. Installation Precautions
- Avoid violent impacts during installation to prevent damage to the internal magnets or impeller.
- Ensure there is no residual air or strong pulsating flow in the pipeline to avoid affecting measurement accuracy.
- Before wiring, please ensure that the power supply voltage is within the range of 5-24VDC, and do not reverse the positive and negative terminals.
