PH4502C Analog Liquid pH Sensor Module with BNC Probe – pH 0–14
The PH4502C Analog Liquid pH Sensor is designed for measuring the acidity or alkalinity of liquids in Arduino, water-quality monitoring, hydroponics, aquarium, laboratory, and educational projects.
The system uses a pH electrode connected through a BNC connector and an electronic signal-conditioning board that converts the electrode signal into an analog voltage that can be measured by a compatible microcontroller.
With a measurement range covering pH 0–14, the module provides a practical solution for building electronic liquid pH monitoring systems.
Technical Specifications
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Model: PH4502C-Type
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Product Type: Analog Liquid pH Sensor Module
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Measurement Range: pH 0–14
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Supply Voltage: 5 ± 0.2 V DC
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Working Current: 5–10 mA
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Power Consumption: ≤0.5 W
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Output Type: Analog Voltage Signal
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Probe Interface: BNC Connector
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Detection Temperature Range: 0–60°C on Common PH4502C Versions
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Response Time: ≤5 Seconds
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Stability Time: ≤60 Seconds
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Module Operating Temperature: -10°C to +50°C
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Operating Humidity: Up to 95% RH
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Module Dimensions: Approx. 42 × 32 × 20 mm
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Suitable For: Arduino & Other ADC-Equipped Microcontrollers
pH 0–14 Measurement
The sensor can be used to monitor liquids across the standard pH scale:
- pH below 7 – Acidic
- pH 7 – Neutral
- pH above 7 – Alkaline / Basic
This makes it suitable for water-monitoring experiments, hydroponics, aquariums, educational systems, and other applications requiring electronic pH measurement.
Analog Signal Output
The PH4502C interface board conditions the very small electrical signal produced by the pH electrode and provides an analog voltage output suitable for measurement by a microcontroller ADC.
The microcontroller can then convert the measured voltage into an estimated pH value through software.
For reliable results, the system should be calibrated using known pH buffer solutions.
BNC Electrode Interface
The module features a standard BNC connector for connecting a compatible pH electrode.
The electrode is placed into the liquid being measured, while the electronic interface board remains outside the liquid.
Only the appropriate sensing section of the probe should be immersed. The PH4502C electronic board is not waterproof and must be kept dry.
Calibration
Calibration is an important part of obtaining useful pH measurements.
Common calibration buffer solutions include:
Using known reference solutions allows the system to compensate for differences in electrode characteristics, interface-board adjustment, temperature, and electrode aging.
The module commonly includes adjustment potentiometers that may be used during setup and calibration.
Arduino & Microcontroller Integration
The sensor can be integrated with controllers such as:
- Arduino Uno
- Arduino Mega
- Arduino Nano
- ESP32
- STM32
- Raspberry Pi Pico
- PIC / AVR Controllers
- Other ADC-Equipped Microcontrollers
The analog output is connected to a suitable ADC input on the controller.
For 3.3 V microcontrollers such as the ESP32, verify the actual analog output voltage before connecting it directly to the ADC input.
A standard Raspberry Pi computer does not include a built-in analog input, so an external ADC is required.
Applications
Ideal for water-quality monitoring, hydroponics, aquariums, Arduino projects, ESP32 monitoring systems, laboratory experiments, environmental monitoring, agricultural projects, liquid testing, educational electronics, automated growing systems, and IoT water-monitoring projects.
Important Note
This sensor should be calibrated before relying on its measurements. Accuracy depends on electrode condition, calibration quality, temperature, electrical noise, contamination, and the characteristics of the liquid being tested.
The pH electrode should be handled and stored correctly. Many glass pH electrodes should not be allowed to dry out for extended periods and normally require an appropriate storage solution.
Do not immerse the PH4502C electronic interface board in liquid.
This type of module is suitable for projects and general monitoring. For professional laboratory, medical, food-safety, industrial compliance, or regulatory measurements, use appropriately calibrated and certified instrumentation.
Exact specifications can vary among PH4502C-compatible boards and supplied electrodes.
Package Includes
- 1 × PH4502C Analog pH Sensor Interface Module
- 1 × pH Electrode Probe with BNC Connector
