DFRobot Gravity 7/24 Industrial Analog pH Sensor Meter Kit for Arduino

⚗️ DFRobot Gravity 7/24 Industrial Analog pH Sensor Meter Kit — Technical Information
🔍 Overview
The DFRobot Gravity 7/24 Industrial Analog pH Sensor Meter Kit is a professional-grade analog pH measurement system designed for continuous (24/7) liquid monitoring.
Measures:
pH level (acidity/alkalinity)
Range:
0 to 14 pH
Output:
Analog voltage (linear)
Designed for:
Long-term industrial and environmental monitoring
👉 It combines an industrial glass electrode + signal conditioning circuit.
⚙️ Working Principle
🧪 Electrochemical pH Measurement
1. ⚗️ Glass Electrode Sensing
Uses a sensitive glass membrane electrode
When immersed in liquid:
Hydrogen ion concentration (H⁺) creates a potential difference
2. 🔋 Reference Electrode System
Uses Ag/AgCl reference electrode with electrolyte (KCl solution)
Provides a stable reference voltage
3. 🔄 Voltage Generation
pH value produces a small voltage:
Acidic → higher positive potential
Alkaline → lower potential
4. 📡 Signal Conditioning
Internal circuit amplifies and converts signal → linear analog output
👉 Output voltage corresponds directly to pH value (0–14)
📊 Measurement Characteristics
pH Range: 0 – 14 pH
Accuracy: ±0.1 pH (at 25°C)
Response time: ≤ 1 minute
Output: Linear analog voltage
Stability Features
Good reproducibility
Low drift
Excellent thermal stability
⚡ Electrical Characteristics
Supply voltage: 5V
Output type: Analog (to ADC/microcontroller)
Low noise signal conditioning
🔗 Interface & Connectivity
BNC connector → pH probe connection
PH2.0 connector → analog output interface
Compatible with:
Microcontrollers (ADC input required)
👉 Plug-and-play style connection system.
🧠 Internal Features
✔ Industrial Glass Electrode
Low impedance glass membrane
Fast response
High sensitivity
✔ Anti-Pollution Design
PTFE ring membrane:
Prevents clogging
Suitable for long-term use
✔ Stable Reference System
Ag/AgCl electrolyte bridge ensures:
Stable voltage
Reliable readings
✔ Gain Adjustment
Onboard potentiometer:
Used for calibration tuning
✔ Power Indicator
LED indicates module operation
🔄 Operating Behavior
✔ Continuous Monitoring (7/24)
Designed for long-term online measurement
Electrode lifespan:
~1 year (typical)
✔ Calibration Requirement
Requires two-point calibration:
Typically using buffer solutions:
pH 4.0
pH 7.0
✔ Analog Output Processing
Requires:
ADC conversion
Software mapping to pH value
🌡️ Environmental Characteristics
Operating temperature:
0°C to 60°C
Suitable Liquids
Water
Aqueous solutions
Non-corrosive liquids
⚠️ Limitations
Requires:
Regular calibration
Electrode:
Must be kept moist (KCl solution)
Sensitive to:
Temperature variation
Contamination
Analog output:
Needs proper filtering and ADC for accuracy
🔌 Typical Pin Configuration
VCC → 5V
GND → Ground
AOUT → Analog pH signal
🧩 Functional Role
The kit acts as a:
pH measurement system
Liquid quality monitoring sensor
Industrial chemical sensing device
🏁 Summary
The DFRobot Gravity 7/24 Industrial pH Sensor Kit is a high-reliability pH sensing solution that:
Uses glass electrode electrochemical sensing
Measures full pH range (0–14)
Provides linear analog output
Supports continuous 24/7 monitoring
Offers high accuracy (±0.1 pH) and stability