1. Introduction
This manual provides detailed instructions for the installation, operation, and maintenance of the DIGITEN G1/2" Water Flow Hall Sensor Switch, Model FL408-1. This sensor is designed to measure water flow rates in various applications, providing a pulse signal output proportional to the flow.
2. Product Overview
The DIGITEN FL408-1 is a compact and easy-to-install water flow sensor featuring a G1/2" external thread. It incorporates a magnetic Hall effect sensor that generates an electrical pulse for each revolution of its internal rotor, allowing for precise flow measurement. The sensor is designed for durability with waterproof, heat-resistant, pressure-resistant, and cold-resistant properties.
Figure 1: Top view of the DIGITEN G1/2" Water Flow Hall Sensor Switch, showing the product label with model number FL-408, working range, water pressure, frequency formula, and wiring color codes.
Figure 2: The water flow sensor connected to its 1.2-meter cable, illustrating the complete assembly for installation.
Figure 3: Bottom view of the water flow sensor, highlighting the arrow indicating the correct direction of water flow for proper operation.
Key Features:
- Compact and lightweight design for easy installation.
- Integrated magnetic Hall effect sensor for pulse output.
- Sealed sensor from water pipe for safety and dryness.
- Durable construction: waterproof, heat-resistant, pressure-resistant, and cold-resistant.
- Standard G1/2" external thread for common pipe connections.
3. Specifications
| Parameter | Value |
|---|---|
| External Thread Diameter | G1/2" (BSP) |
| Frequency Formula | F = 7.5 * Q (L/Min) |
| Measurement Error | ±2% |
| Working Voltage Range | DC 3-24 V |
| Maximum Current | 15 mA (DC 5V) |
| Load Capacity | ≤10 mA (DC 5V) |
| Flow Range | 1-30 L/min |
| Operating Temperature | ≤80°C |
| Operating Humidity | 35% ∼ 90% RH |
| Allowable Compression | Water pressure 1.75 Mpa below |
| Insulation Resistance | >100M OHM |
| Storage Temperature | -25°C ∼ +80°C |
| Storage Humidity | 25% ∼ 95% RH |
| Output Waveform | Square Wave, Pulse Signal |
| Cable Length | 120 cm |
| Model Number | FL408-1 |
4. Setup and Installation
4.1 Safety Precautions
- Ensure the water supply is turned off before installation to prevent leaks.
- Verify that the operating voltage (DC 3-24V) matches your power source to avoid damage.
- Do not exceed the maximum water pressure of 1.75 Mpa.
- Handle wiring carefully to prevent short circuits.
4.2 Mechanical Installation
- Select Location: Choose a section of the water pipe where the sensor can be easily integrated. Ensure there is sufficient space for the sensor and its connections.
- Prepare Pipe: Turn off the main water supply. Cut the pipe at the desired installation point.
- Orient Sensor: Observe the arrow on the bottom of the sensor (refer to Figure 3). This arrow indicates the direction of water flow. Install the sensor so that the arrow aligns with the intended flow direction in your pipe system.
- Connect to Pipe: Use appropriate G1/2" fittings (not included) to connect the sensor into the water line. Ensure connections are tight to prevent leaks. Thread sealant tape (PTFE tape) is recommended for a secure, watertight seal.
- Restore Water Supply: Slowly turn on the water supply and check for any leaks around the sensor connections.
4.3 Electrical Connection
The sensor comes with a 1.2m cable with three wires. Connect these wires to your control system (e.g., microcontroller, PLC) as follows:
- Red Wire: Connect to VCC (+) (DC 3-24V power supply).
- Black Wire: Connect to GND (-) (Ground).
- Yellow Wire: Connect to Signal Output (Pulse signal).
Ensure all electrical connections are secure and insulated to prevent electrical hazards.
5. Operating Instructions
Once installed and connected, the sensor will output a square wave pulse signal on the yellow wire. The frequency of this pulse is directly proportional to the water flow rate.
5.1 Flow Rate Calculation
The relationship between the output pulse frequency (F) and the water flow rate (Q) is given by the formula:
F = 7.5 * Q
Where:
- F = Frequency in Hertz (Hz), measured from the yellow signal wire.
- Q = Flow rate in Liters per Minute (L/Min).
To calculate the flow rate (Q) from the measured frequency (F), use the rearranged formula:
Q = F / 7.5
For example, if your control system measures a pulse frequency of 75 Hz, the flow rate would be 75 / 7.5 = 10 L/Min.
5.2 Integration with Microcontrollers
The pulse signal can be read by microcontrollers (e.g., Arduino, Raspberry Pi) using an interrupt pin or by polling a digital input. The microcontroller can then calculate the flow rate and display it, log it, or use it for control purposes.
6. Maintenance
The DIGITEN water flow sensor is designed for low maintenance. However, periodic checks can ensure optimal performance and longevity.
- Leak Inspection: Regularly check all pipe connections for any signs of water leakage. Tighten fittings if necessary.
- Debris Check: If flow readings become erratic or stop, inspect the sensor for any debris or blockages that might impede the internal rotor. If necessary, disconnect the sensor (after turning off water supply) and carefully clean it.
- Electrical Connections: Periodically inspect the wiring for any signs of wear, corrosion, or loose connections.
- Environmental Conditions: Ensure the sensor operates within its specified temperature and humidity ranges to prevent damage.
7. Troubleshooting
| Problem | Possible Cause | Solution |
|---|---|---|
| No pulse signal output |
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| Inaccurate flow readings |
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| Water leakage at connections |
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8. Warranty and Support
DIGITEN provides a one-year warranty for any quality problems with their products. For technical support or warranty claims, please contact DIGITEN customer service through the retailer where the product was purchased or visit the official DIGITEN store page.
Online Store: DIGITEN Store on Amazon
