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PH Electrode Probe BNC Connector

BE15000114

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Warning:

It doesn't bring PH2.0 sensor interface! Only the probe!

Need to measure water quality and other parameters but haven't got any low cost pH meter? Find it difficult to use with Arduino? Here comes an analog pH meter, specially designed for Arduino controllers and has built-in simple, convenient and practical connection and features.

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19,90 € com IVA

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Warning:

It doesn't bring PH2.0 sensor interface! Only the probe!

 

Specification

  • BNC connector, suitable for most pH meter and controller with BNC connector. 
  • Suitable for wide range of application: Aquariums, Hydroponics, Laboratory etc. 
  • Measurement range: 0.00-14.00 PH 
  • Zero-point: 7 +- 0.5PH 
  • Alkali Error: 0.2PH 
  • Theoretical Percentage Slope: ≥98.5% 
  • Internal Resistance: ≤250MΩ 
  • Terminal Blocks: BNC plug 
  • Cable length: Approx. 70cm
  • Module Power: 5.00V
  • Circuit Board Size: 43mm×32mm
  • Measuring Temperature:0-60 ℃
  • Accuracy: ± 0.1pH (25 ℃)
  • Response Time: ≤ 1min
  • pH Sensor with BNC Connector
  • PH2.0 Interface ( 3 foot patch )
  • Gain Adjustment Potentiometer
  • Power Indicator LED

 

 

pH Electrode Characteristics

The output of pH electrode is Millivolts,and the pH value of the relationship is shown as follows (25 ℃):

Ph-mv.jpg
 

Usage

Connecting Diagram

PH meter connection1 (1).png

NOTE:
  • Please make sure the power supply is as close as possible to the +5.00V. More accurate the voltage, higher the accuracy!
  • Before the use of the electrode every time, you need tocalibrate it by the standard solution to obtain more accurate results. And subsection calibration could help you get a better accuracy.
    • If you measure the acidic sample, the pH value of the standard solution should be 4.00.
    • If you measure the alkaline sample, the pH value of the standard solution should be 9.18.
  • Before the pH electrode measured different solutions, you need to use water to wash it. We recommend deionized water.
  • The most suitable environment temperature is about 25 ℃, the result is very close to the actual pH value.

 

Steps

(1) Connect equipments according to the graphic,that is,the pH electrode is connected to the BNC connector on the pH meter board,and then use the connection lines,the pH meter board is connected to the ananlong port 0 of the Arduino controller. When the Arduino controller gets power,you will see the blue LED on board is on.

(2) Upload the sample code to the Arduino controller.

(3) Put the pH electrode into the standard solution whose pH value is 7.00,or directly shorted the input of the BNC connector.Open the serial monitor of the Arduino IDE,you can see the pH value printed on it,and the error does not exceed 0.3. Record the pH value printed,then compared with 7.00, and the difference should be changed into the "Offset" in the sample code. For example,the pH value printed is 6.88,so the difference is 0.12.You should change the "# define Offset 0.00" into "# define Offset 0.12" in your program.

(4) Put the pH electrode into the pH standard solution whose value is 4.00.Then wait about one minute,adjust the gain potential device, let the value stabilise at around 4.00.At this time,the acidic calibration has been completed and you can measure the pH value of an acidic solution.

If you want to measure the pH value of other solution, you must wash the pH electrode first!

(5) According to the linear characteristics of pH electrode itself, after the above calibration,you can directly measure the pH value of the alkaline solution, but if you want to get better accuracy, you can recalibrate it. Alkaline calibration use the standard solution whose pH value is 9.18.Also adjust the gain potential device, let the value stabilise at around 9.18. After this calibration, you can measure the pH value of the alkaline solution.

 

Sample Code

Sample code for testing the PH meter and get the sensor feedback from the Arduino Serial Monitor.

/*
# This sample code is used to test the pH meter V1.0.
# Editor : YouYou
# Ver : 1.0
# Product: analog pH meter
# SKU : SEN0161
*/
#define SensorPin A0 //pH meter Analog output to Arduino Analog Input 0
#define Offset 0.00 //deviation compensate
#define LED 13
#define samplingInterval 20
#define printInterval 800
#define ArrayLenth 40 //times of collection
int pHArray[ArrayLenth]; //Store the average value of the sensor feedback
int pHArrayIndex=0;
void setup(void)
{
pinMode(LED,OUTPUT);
Serial.begin(9600);
Serial.println("pH meter experiment!"); //Test the serial monitor
}
void loop(void)
{
static unsigned long samplingTime = millis();
static unsigned long printTime = millis();
static float pHValue,voltage;
if(millis()-samplingTime > samplingInterval)
{
pHArray[pHArrayIndex++]=analogRead(SensorPin);
if(pHArrayIndex==ArrayLenth)pHArrayIndex=0;
voltage = avergearray(pHArray, ArrayLenth)*5.0/1024;
pHValue = 3.5*voltage+Offset;
samplingTime=millis();
}
if(millis() - printTime > printInterval) //Every 800 milliseconds, print a numerical, convert the state of the LED indicator
{
Serial.print("Voltage:");
Serial.print(voltage,2);
Serial.print(" pH value: ");
Serial.println(pHValue,2);
digitalWrite(LED,digitalRead(LED)^1);
printTime=millis();
}
}
double avergearray(int* arr, int number){
int i;
int max,min;
double avg;
long amount=0;
if(number<=0){
Serial.println("Error number for the array to avraging!/n");
return 0;
}
if(number<5){ //less than 5, calculated directly statistics
for(i=0;i<number;i++){
amount+=arr[i];
}
avg = amount/number;
return avg;
}else{
if(arr[0]<arr[1]){
min = arr[0];max=arr[1];
}
else{
min=arr[1];max=arr[0];
}
for(i=2;i<number;i++){
if(arr[i]<min){
amount+=min; //arr<min
min=arr[i];
}else {
if(arr[i]>max){
amount+=max; //arr>max
max=arr[i];
}else{
amount+=arr[i]; //min<=arr<=max
}
}//if
}//for
avg = (double)amount/(number-2);
}//if
return avg;
}

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