I. Product Overview
The A128-A is a high-precision flow sensor based on the Hall effect, with built-in temperature detection. An internal impeller (including a magnet) rotates with the fluid; the Hall element senses changes in the magnetic field and outputs a pulse signal proportional to the flow rate. It also integrates a thermistor for real-time monitoring of the fluid temperature. The product features fast response and high stability, making it suitable for liquid metering and control applications requiring simultaneous flow and temperature detection.
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. |
| Temperature detection | Thermistor resistance: 3950 / 50K ± 1% |
| Wiring definition and plug specifications | Plug: C3B-4P white terminal (4×650mm), cable length can be customized.
Red: Positive power supply (5-24VDC) Black: Negative power supply (GND) Blue: Signal output (connected to host I/O port) Black and yellow: Temperature sensor output |
| Frequency-flow relationship | F = 11 × Q ± 10% （F：Hz，Q：L/MIN） |
III. Frequency-Flow Characteristics Reference Table
| Flow (L/MIN) | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 |
| Reference frequency (Hz) | 11 | 22 | 33 | 44 | 55 | 66 | 77 | 88 | 99 | 110 |
| -10% Frequency (Hz) | 9.9 | 19.8 | 29.7 | 39.6 | 49.5 | 59.4 | 69.3 | 79.2 | 89.1 | 99 |
| +10% Frequency (Hz) | 12.1 | 24.2 | 36.3 | 48.4 | 60.5 | 72.6 | 84.7 | 96.8 | 108.9 | 121 |
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.
