PH Sensor Meter Kit V2

The DFRobot Gravity: Analog pH meter V2 is specifically designed to measure the pH of the solution and reflect the acidity or alkalinity. It is commonly used in various applications such as aquaponics, aquaculture, and environmental water testing.

As an upgraded version of pH meter V1, this product greatly improves the precision and user experience. The onboard voltage regulator chip supports the wide voltage supply of 3.3~5.5V, which is compatible with 5V and 3.3V main control board. The output signal filtered by hardware has low jitter. The software library adopts the two-point calibration method, and can automatically identify two standard buffer solutions (4.0 and 7.0), so simple and convenient.

With this product, main control board (such as Arduino) and the software library, you can quickly build the pH meter, plug and play, no welding. DFRobot provides a variety of water quality sensor products, uniform size and interface, not only meet the needs of various water quality testing, but also suitable for the DIY of multi-parameter water quality tester.

Quick Spec

Signal Conversion Board (Transmitter) V2

• Supply Voltage: 3.3~5.5V
• Output Voltage: 0~3.0V
• Probe Connector: BNC
• Signal Connector: PH2.0-3P
• Measurement Accuracy: ±0.1@25℃
• Dimension: 42 x 32mm

pH Probe

• Probe Type: Laboratory Grade
• Detection Range: 0~14
• Temperature Range: 5~60°C
• Zero Point: 7±0.5
• esponse Time: <2min
• Internal Resistance: <250MΩ
• Probe Life: >0.5 year (depending on frequency of use)
• Cable Length: 100cm

PLEASE NOTE
1. The BNC connector and the signal conversion board must be kept dry and clean, otherwise, it will affect the input impedance, resulting in an inaccurate measurement. If it is damp, it needs to be dried.
2. The signal conversion board cannot be directly placed on a wet or semiconductor surface, otherwise, it will affect the input impedance, resulting in the inaccurate measurement. It is recommended to use the nylon pillar to fix the signal conversion board, allow a certain distance between the signal conversion board and the surface.
3. The sensitive glass bubble in the head of the pH probe should avoid touching with the hard material. Any damage or scratches will cause the electrode to fail.
4. After completing the measurement, disconnect the pH probe from the signal conversion board. The pH probe should not be connected to the signal conversion board without the power supply for a long time.

Wiring Diagram

Calibrating an Analog pH Sensor

Sample Code

/*
 * file DFRobot_PH.ino
 * @ https://github.com/DFRobot/DFRobot_PH
 *
 * This is the sample code for Gravity: Analog pH Sensor / Meter Kit V2, SKU:SEN0161-V2
 * In order to guarantee precision, a temperature sensor such as DS18B20 is needed, to execute automatic temperature compensation.
 * You can send commands in the serial monitor to execute the calibration.
 * Serial Commands:
 *   enter -> enter the calibration mode
 *   cal -> calibrate with the standard buffer solution, two buffer solutions(4.0 and 7.0) will be automaticlly recognized
 *   exit -> save the calibrated parameters and exit from calibration mode
 *
 * Copyright   [DFRobot](http://www.dfrobot.com), 2018
 * Copyright   GNU Lesser General Public License
 *
 * version  V1.0
 * date  2018-04
 */

#include "DFRobot_PH.h"
#include 

#define PH_PIN A1
float voltage,phValue,temperature = 25;
DFRobot_PH ph;

void setup()
{
  Serial.begin(115200);
  ph.begin();
}

void loop()
{
    static unsigned long timepoint = millis();
    if(millis()-timepoint>1000U)  //time interval: 1s
    {
      timepoint = millis();
      voltage = analogRead(PH_PIN)/1024.0*5000;  // read the voltage
      //temperature = readTemperature();  // read your temperature sensor to execute temperature compensation
      phValue = ph.readPH(voltage,temperature);  // convert voltage to pH with temperature compensation
      Serial.print("temperature:");
      Serial.print(temperature,1);
      Serial.print("^C  pH:");
      Serial.println(phValue,2);
    }
    ph.calibration(voltage,temperature);  // calibration process by Serail CMD
}

float readTemperature()
{
  //add your code here to get the temperature from your temperature sensor
}

Resources

• Product Page
• Product Wiki
• DFRobot PH Library
• Board Layout and Dimensions

Shipping List

• 1 x pH Probe(Laboratory Grade)
• 1 x pH Signal Conversion Board
• 1 x Gravity Analog Sensor Cable
• 2 x pH Standard Buffer Solution 4.0
• 2 x pH Standard Buffer Solution 7.0
• 2 x Waterproof Gasket
• 1 x Screw Cap for BNC Connector
• 4 x M3 * 10 nylon pillar
• 8 x M3 * 5 screw