The Gravity Analog TDS Sensor/Meter is an Arduino-compatible water quality sensor designed to measure TDS (Total Dissolved Solids) in water. TDS reflects the cleanliness and purity of water by measuring how many soluble solids are present. This makes the sensor ideal for domestic water, hydroponics, and general liquid testing.
With clear analog output and waterproof probe design, this sensor kit allows you to easily build DIY TDS meters or automated water monitoring systems. It’s plug-and-play for Arduino beginners and makers.
How It Works
TDS measures the total amount of dissolved substances in water (in ppm). The higher the TDS, the more impurities it contains. Ideal drinking water typically has TDS < 300 ppm, while values above 500 ppm are considered contaminated.
The TDS sensor module converts this into a 0~2.3V analog output, which can be read by any Arduino analog input pin. The excitation source is AC to prevent polarization, improving probe durability and measurement stability.
Key Features
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Wide Voltage Support: Operates from 3.3V to 5.5V
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Analog Output: 0 – 2.3V, compatible with 3.3V / 5V systems
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Waterproof Probe: Long-term immersion for continuous use
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AC Excitation Source: Prevents probe polarization
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Easy Arduino Integration: No soldering needed, plug-and-play
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Affordable alternative to expensive professional TDS testers
Applications
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Domestic water testing
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Hydroponic nutrient monitoring
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Aquarium water quality control
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Agriculture irrigation systems
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Environmental science education
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Smart water purifiers (recommend pairing with Gravity: Waterproof DS18B20 )
Technical Specifications
Signal Transmitter Board
| Parameter | Value |
|---|---|
| Input Voltage | 3.3V ~ 5.5V |
| Output Voltage | 0 ~ 2.3V |
| Working Current | 3 ~ 6mA |
| TDS Measurement Range | 0 ~ 1000 ppm |
| Accuracy | ±10% F.S. (at 25°C) |
| Size | 42 × 32 mm |
| Module Interface | PH2.0-3P |
| Probe Interface | XH2.54-2P |
TDS Probe
| Parameter | Value |
|---|---|
| Needle Count | 2 |
| Length | 83 cm |
| Connector Type | XH2.54-2P |
| Color | Black |
| Waterproof Rating | Yes (probe head & cable only) |
Note: The signal board is not waterproof. Avoid water contact beyond the probe.
Real Projects Using This Sensor
1. Arduino Hydroponics Monitoring System
Measure water nutrient content alongside pH/EC sensors.
2. Water Quality Display with LCD
Read TDS values in real-time on an LCD screen.
3. IoT Water Monitoring (ESP32 + Bluetooth)
Send water TDS data to smartphones via ESP32 and monitor remotely.
4. Filter Comparison Experiment
Compare water quality before and after filtration for DIY testing.
5. Water Quality Monitoring with Gravity TDS Sensor and LCD Display
Introduction: This project demonstrates how to interface the Gravity Analog TDS Sensor with an Arduino to measure TDS levels in water and display the results in real-time using a 16×2 LCD screen. It's a simple and effective solution for visualizing water quality data in PPM (parts per million).
Shipping List
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1 × Analog TDS Meter for Arduino
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1 × Waterproof TDS Probe
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1 × 3-Pin Analog Sensor Cable