Analog TDS Sensor Module

Product Description

The Arduino-Compatible TDS Sensor / Meter Kit is an easy-to-use water quality testing module designed to measure the Total Dissolved Solids (TDS) present in water. TDS represents the total amount of dissolved organic and inorganic substances in water and is commonly expressed in ppm (parts per million) or mg/L.

This TDS sensor kit provides an affordable solution for integrating water quality monitoring into Arduino and other microcontroller-based projects. Unlike handheld TDS pens, which are mainly designed for manual measurement, this module provides an analog voltage output that can be read by a controller for online monitoring, data logging, display, and automated water-quality analysis.

The signal transmitter board accepts an input voltage of 3.3–5.5 V and provides a 0–2.3 V analog output, making it compatible with both 3.3 V and 5 V controller systems. Its low working current of approximately 3–6 mA makes it suitable for embedded and portable applications.

The module uses an AC excitation source to help reduce electrode polarization during measurement. The included TDS probe is designed for water-quality applications and can be used for domestic water, hydroponics, and other suitable water-testing applications.

With a measurement range of approximately 0–1000 ppm and specified accuracy of ±10% F.S. at 25°C, this module is suitable for educational projects, DIY water-quality monitors, IoT systems, and Arduino-compatible applications.

Features

• Arduino-compatible TDS water quality sensor
• Measures Total Dissolved Solids (TDS) in water
• TDS measurement range of 0–1000 ppm
• 0–2.3 V analog signal output
• Compatible with 3.3 V and 5 V controllers
• Input voltage range of 3.3–5.5 V
• Low working current of approximately 3–6 mA
• AC excitation source helps reduce probe polarization
• Waterproof TDS probe
• Easy plug-and-play connection
• No soldering required for basic connection
• Suitable for Arduino and other microcontrollers
• Useful for online water quality monitoring
• Compact transmitter board
• Suitable for domestic water testing
• Suitable for hydroponic applications
• Affordable alternative for DIY water-quality monitoring

Specifications

Parameter	Specification
Product Type	TDS Sensor / Meter Kit
Application	Water Quality Measurement
Measurement Parameter	Total Dissolved Solids (TDS)
TDS Measurement Range	0–1000 ppm
Input Voltage	3.3–5.5 V
Analog Output Voltage	0–2.3 V
Working Current	3–6 mA
Measurement Accuracy	±10% F.S. at 25°C
Excitation Method	AC Excitation
Probe Type	Waterproof TDS Probe
Signal Interface	PH2.0-3P
Electrode Interface	XH2.54-2P
Board Size	Approximately 42 × 32 mm
Controller Compatibility	3.3 V / 5 V Controllers
Connection Type	Plug and Play

What is TDS?

TDS (Total Dissolved Solids) refers to the total concentration of dissolved substances present in water. These substances can include various dissolved salts, minerals, metals, and other organic or inorganic materials.

TDS is generally expressed in ppm or mg/L. A higher TDS value indicates a greater concentration of dissolved substances in the water.

TDS can be used as one of the reference parameters for assessing water quality, but TDS alone does not identify which substances are dissolved in the water and should not be considered a complete measure of water safety or purity.

Working Principle

The TDS probe is placed in the water being tested. The sensor generates an electrical measurement related to the dissolved ionic content of the water.

The transmitter board processes the probe signal and produces a corresponding analog voltage between 0 and 2.3 V. A connected Arduino or other microcontroller can read this analog voltage through an ADC input and calculate or display the corresponding TDS value.

The module uses an AC excitation signal rather than continuous DC excitation, which helps reduce electrode polarization and supports more stable measurement.

For improved measurement results, temperature compensation and suitable calibration should be applied according to the application and water conditions.

Analog Output

The sensor provides a 0–2.3 V analog output that can be directly read by a compatible analog input.

This allows the module to be integrated into systems for:

• Real-time TDS display
• Water-quality monitoring
• Data logging
• IoT applications
• Automatic water-quality analysis
• Microcontroller-based measurement systems

The analog output makes the module more suitable for automated monitoring than a basic handheld TDS pen.

Controller Compatibility

The transmitter board operates from 3.3–5.5 V and provides a maximum analog output of approximately 2.3 V. This makes it suitable for use with many Arduino-compatible 5 V controllers as well as 3.3 V microcontrollers, provided the analog input specifications of the controller are observed.

It can be integrated with suitable development boards for displaying, recording, or transmitting TDS measurements.

Probe and Connections

The module uses a dedicated electrode connection through an XH2.54-2P interface. The signal transmitter board provides a PH2.0-3P interface for connection to the controller/system.

The included probe is designed for water measurement and should be used according to the recommended operating conditions.

Applications

• Arduino water quality monitoring
• Domestic water testing
• Hydroponics
• Water purification projects
• DIY TDS meters
• IoT water monitoring
• Water-quality data logging
• Aquarium-related monitoring projects
• Educational electronics projects
• Microcontroller-based water testing
• Smart water monitoring systems
• Laboratory prototypes
• Embedded water-quality systems
• Automated water-quality analysis
• Portable water testing projects

Package Includes

• 1 × V1.0 TDS Sensor / Meter Development Board, approximately 42 × 32 mm
• 1 × TDS Water Quality Probe

Product Disclaimer

The TDS measurement is an indication of the total dissolved solids present in water and does not identify individual dissolved substances or determine whether water is safe for drinking. TDS should be used as one of several parameters when evaluating water quality.

The specified accuracy of ±10% F.S. at 25°C is provided as a product specification. Actual readings may vary depending on water temperature, probe condition, calibration, water composition, installation, electrical noise, and measurement conditions.

For reliable measurements, proper calibration and temperature compensation are recommended where required. The probe should be cleaned and maintained according to the application.

Product images are shown for illustrative and representational purposes only. The actual product colour, dimensions, connector design, component placement, and appearance may vary slightly depending on the manufacturing batch.