[Industrial] Gravity: Analog ORP Sensor Meter PRO (แท้จาก DFRobot)

FEATURES

• 24-hour online ORP monitoring

APPLICATIONS

• ORP monitoring system

SPECIFICATION

ORP Signal Converter

• Input Voltage: 5V
• Input Signal: 0.5V ~ 4.5V
• Input Interface: 5.08mm/0.20" Pluggable Connector
• Measuring Range: -2000mV ~ +2000mV
• Output Interface: PH2.0 - 3Pin
• Module Size: 42mm×32mm/1.65×1.26"

Industrial ORP Probe

• Indicator Electrode: Platinum
• Reference Electrode: silver-silver chloride
• Suitable Temperature: 5-70℃
• Electrode Potential: 245mV ~ 270mV
• Reference Electrode Internal Resistance: ≤10KΩ
• Electrode Stability: ±8mV/24h

DOCUMENTS

• Product wiki

SHIPPING LIST

• Gravity: Analog ORP Signal Converter x1
• Industrial ORP Probe x1
• Waterproof Aviation Cable Connector x1
• Waterproof Cable Gland x1
• Nylon Screw x1
• Nylon Column x1

Board Overview

Electrode Input

• S+: Electrode +
• S-: Electrode -

Signal Output

• A: Analog Output
• +: Power Supply +
• -: Power Supply -

Tutorial

Requirements

• Hardware

  • DFRduino UNO Controller x 1
  • Gravity Analog ORP Sensor PRO x 1

• Software

  • Arduino IDE
  • DFRobot_ORP_PRO Library

Connection Diagram

Operation

1. Connect modules according to the wiring diagram

2. Upload the sample code and insert the probe into the liquid to be tested

⚠ Measurement Note

• Simply insert the terminal electrode into the measured liquid and read the data. ORP probes are not completely waterproof, so do not immerse the probe all the way into the liquid.

• It is recommended to use high-quality linear regulated power source or fully-charged lithium battery to supply power for Arduino. The closer the voltage is to 5V, the less the voltage changes, and the higher the measurement accuracy will be.

• ORP electrodes can be used directly without calibration. ORP standards can be used to detect if the probe or signal converter is damaged only when the test results are in doubt.

#include "DFRobot_ORP_PRO.h"

#define PIN_ORP A1
#define ADC_RES 1024
#define V_REF 5000

float ADC_voltage;

DFRobot_ORP_PRO ORP(0);

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

void loop() {
ADC_voltage = ((unsigned long)analogRead(PIN_ORP) * V_REF + ADC_RES / 2) / ADC_RES;
Serial.print("ORP value is : ");
Serial.print(ORP.getORP(ADC_voltage));
Serial.println("mV");
delay(1000);
}

ORP value is: 244 mV
ORP value is: 244 mV
ORP value is: 245 mV
ORP value is: 245 mV
ORP value is: 245 mV

Accuracy Improvement

Due to differences among electronic components and interference from power supply, notable errors may be resulted in when measuring directly. The following methods are recommended to reduce errors and improve accuracy.

1. Provide a accurately stable 5V power supply or reference voltage for the MCU or ADC used to read the analog voltage

2. Calibrate ORP signal converter as follows:

Zero Calibration

Although voltage reference chips can provide stable reference voltage, due to the differences of electronic components, there may be up to 50mV voltage differences among different chips. ORP measurement accuracy can be improved by measuring reference voltage in advance for correction.

1. Remove the ORP probe and use wire to short-circuit the S+ and S- pins of the ORP signal converter

2. Upload sample code -1 and turn on the serial port monitor to record the reference voltage

3. Revise sample code -2, set the 0 in DFRobot_ORP_PRO ORP(0); to the just recorded reference voltage value

4. Upload the sample code -2, the sensor readings will be corrected at the point

If the power supply or ORP signal converter is replaced, the correction value needs to be recalibrated.

#define PIN_ORP A1
#define ADC_RES 1024
#define V_REF 5000

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

void loop()
{
Serial.println((((long)analogRead(PIN_ORP)*V_REF + ADC_RES / 2) / ADC_RES) - 2480);
delay(1000);
}

#include "DFRobot_ORP_PRO.h"

#define PIN_ORP A1
#define ADC_RES 1024
#define V_REF 5000

unsigned int ADC_voltage;

DFRobot_ORP_PRO ORP(-9);//set reference voltage mv

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

Serial.print("calibration is: ");
Serial.print(ORP.getCalibration());
Serial.println(" mV");
}

void loop() {
ADC_voltage = ((unsigned long)analogRead(PIN_ORP) * V_REF + ADC_RES / 2) / ADC_RES;
Serial.print("ORP value is: ");
Serial.print(ORP.getORP(ADC_voltage));
Serial.println(" mV");
delay(1000);
}

ORP value is: -59.00 mV
ORP value is: -59.00 mV
ORP value is: -59.00 mV
ORP value is: -59.00 mV
ORP value is: -59.00 mV

Fix Probe

ORP industrial probes can be connected to the container by pipe threads of G3/4

Waterproof Connection

Gravity: Analog ORP Sensor PRO kits come with two types of waterproof connectors that make it easy to set up a waterproof measurement system.

FAQ

• Do the ORP probe need to be calibrated? How often?

  • The ORP probe generally don't need to be calibrated, but you can use ORP standards to detect if the probe or signal converter is damaged only when the test results are in doubt.

• How to clean the ORP probe?

  • Rinse the probe with deionized water or potable water until the tested liquid attached to the electrode is completely removed. Don't use a stiffish brush to clean the probe.

• How long can ORP electrodes be used?

  • ORP electrodes are designed to have service life of one year, which may be shortened if the electrodes are operated in harsh environments with high temperature, thickness or strong corrosion. It is recommended to regularly use ORP standards for testing, and replace it in time when the error increases.