Published March 31, 2026 © GPL3+

PRAHAR – Predictive Industrial Gas Safety System

PRAHAR predicts exact seconds to danger — TTD algorithm warns workers BEFORE gas becomes critical.

IntermediateFull instructions provided10 hours73

PRAHAR – Predictive Industrial Gas Safety System

Things used in this project

Hardware components

Seeed Studio Grove - Piezo Buzzer

// Piezo Buzzer - Audio Alert System // Connected to Digital Pin 8 // // Function: // SAFE Zone (gas < 200) → No sound (Silent) // WARNING Zone (200–400) → Intermittent beeping // DANGER Zone (gas > 400) → Continuous sound (ON) // // The buzzer automatically turns OFF when gas levels return to safe range int buzzer = 8;

Rotary Potentiometer, 10 kohm

// Potentiometer used to simulate MQ-2 gas sensor behavior // Clockwise = increasing gas concentration // Anti-clockwise = decreasing gas concentration // Will be replaced with MQ-2 sensor in real deployment

Arduino UNO

// Arduino UNO R3 - Main Controller // Reads gas sensor data from analog pin A0 // Runs TTD prediction algorithm // Controls buzzer output on digital pin 8 // Communicates data via Serial Monitor (9600 baud)

Male/Female Jumper Wires

// Jumper Wire Connections (Male-Female) // // MQ-2 Sensor Connections: // VCC → Arduino 5V // GND → Arduino GND // A0 → Arduino A0 (Analog Input) // // Buzzer Connections: // Positive (+) → Arduino Pin 8 // Negative (-) → Arduino GND

Solderless Breadboard Full Size

// Solderless Breadboard (Full-size, 830 tie-points) // Used for circuit prototyping without soldering // Allows easy placement and connection of components // Provides power distribution through internal rows and columns // Enables quick modifications and testing of the PRAHAR system

MQ-2 Gas Sensor

// MQ-2 Gas Sensor Module used for detecting LPG, smoke and flammable gases // Provides both analog (A0) and digital (D0) output // Connected to Arduino for real-time gas monitoring // Threshold value set to trigger alert (LED/Buzzer) when gas level increases // Widely used in gas leakage detection and safety systems

Red LED

// Red LED used as alert indicator for high gas concentration // Activated when MQ-2 sensor output crosses preset threshold // Interfaced with Arduino digital pin for automatic control // Connected in series with 220Ω resistor to limit current and ensure safe operation // Provides quick visual indication of hazardous conditions

Yellow LED

// Yellow LED used as intermediate warning indicator for gas detection system // Activated when MQ-2 sensor detects moderate gas concentration // Indicates transition from safe to hazardous condition // Controlled via Arduino digital output based on threshold values // Connected in series with 220Ω resistor for safe current limiting

Green LED

// Green LED used as normal condition indicator in gas detection system // Activated when MQ-2 sensor output is below threshold level // Confirms that the environment is safe and no gas leakage is detected // Controlled via Arduino digital pin based on sensor readings // Connected in series with 220Ω resistor for safe current limiting

Resistor 220 ohm

220Ω Resistor

// 220Ω resistor used for current limiting in LED circuit // Connected in series with LEDs to regulate current according to Ohm’s Law // Prevents overcurrent conditions and protects components from damage // Helps maintain stable voltage and reliable circuit performance // Essential for safe interfacing of LEDs with Arduino outputs

Software apps and online services

Arduino IDE

// Arduino IDE used for developing, compiling and uploading embedded code to Arduino // Interfaces MQ-2 gas sensor for real-time gas detection and LED control // Provides serial communication for monitoring sensor values and debugging // Essential tool for implementing and testing the gas detection system

Hand tools and fabrication machines

Laptop/PC

"For Tinkercad simulation and coding"

Tinkercad

"Used for circuit simulation and design"

Story

PRAHAR: Predictive Gas Hazard Detection & Response System

The Problem

Gas leaks are among the most dangerous hazards in homes, industries, and confined environments. Most existing detection systems trigger alarms only after gas concentration has already reached unsafe levels.By the time an alert is generated, the window for safe intervention is extremely limited—leading to accidents, health risks, and potentially catastrophic outcomes.

The Idea

PRAHAR is designed to shift safety systems from reactive detection to proactive prediction.Instead of waiting for gas levels to cross a threshold, PRAHAR continuously analyzes how quickly the concentration is increasing and estimates the Time-To-Danger (TTD)—the time remaining before conditions become critical.This enables early warnings and provides users with valuable time to take preventive action.

Why PRAHAR is Different

Unlike existing dashboards, PRAHAR introduces a predictive Time-To-Danger metric that gives workers advance warning — not just current readings. Conventional systems operate on a simple logic:Gas crosses threshold → Alarm triggered → Response begins→ Often too latePRAHAR introduces a smarter approach:Gas trend increasing → TTD calculated → Early warning issued→ Action before dangerThis shift from threshold-based detection to rate-based prediction makes PRAHAR a more intelligent and safety-focused solution.

Why PRAHAR is Unique

While gas detection systems are widely used, PRAHAR introduces a simplified, implementable predictive approach that brings early-warning capability to low-cost systems.Its uniqueness lies in:Prediction over detection using rate-based analysisTime-based risk estimation (TTD) instead of static thresholdsLow-cost implementation using accessible hardwareSimulation-first validation for controlled and reliable testingScalable design for future industrial and IoT applications

System Overview

PRAHAR is a simulation-validated
prototype built using Arduino UNO.
Developed and tested on Tinkercad,
where a potentiometer simulates
MQ-2 gas sensor behavior.

Core components:
→ Arduino UNO (processing unit)
→ MQ-2 Gas Sensor (real hardware)
→ Potentiometer (simulation input)
→ Piezo Buzzer (audio alert)
→ Red/Yellow/Green LEDs (visual alert)

The system processes real-time input
and triggers alerts based on predicted
risk levels.

v3.0 Update (March 2026):
Red, Yellow and Green LED visual
alerts added — both audio and visual
indication now available.
→ Green LED — Safe (gas < 250)
→ Yellow LED — Warning (250-400)
→ Red LED — Danger (gas > 400)

Early Warning: System alerts when
TTD drops below 10 seconds!

TTD Prediction Algorithm

The intelligence of PRAHAR lies in its simple yet effective predictive model:Rate of change = Current reading − Previous readingTime-To-Danger (TTD) = (Threshold − Current value) / RateBy evaluating how fast gas levels are rising, the system predicts when a dangerous threshold will be reached—enabling early intervention.

Results

Testing in simulated conditions shows that PRAHAR can:Detect rapidly increasing gas trendsProvide warnings before critical thresholds are reachedAutomatically trigger alerts in high-risk conditionsExample:Gas level reaching ~430 → Danger detected and buzzer activated

Applications

PRAHAR is designed for real-world safety scenarios, including:Domestic LPG leak detectionChemical and process industriesMining and confined spacesLaboratories and storage facilities

Future Scope

PRAHAR is built as a scalable system with strong potential for real-world deployment. Planned enhancements include:Integration of real MQ-2 gas sensorIoT-based remote alert systemsMulti-node monitoring networksAI-based predictive modeling

Conclusion

PRAHAR demonstrates a critical evolution in safety systems—from detecting danger to predicting it.Even as a simulation-validated prototype, it highlights how intelligent analysis of data trends can significantly improve response time and safety outcomes.Because in safety, prediction is not an advantage - it is a necessity. It saves lives.

Code

int gasSensor = A0;
int buzzer = 8;
int prevGas = 0;
int dangerThreshold = 400;

void setup() {
  Serial.begin(9600);
  pinMode(buzzer, OUTPUT);
}

void loop() {
  int gasValue = analogRead(gasSensor);
  int rate = gasValue - prevGas;
  
  Serial.print("Gas: ");
  Serial.print(gasValue);
  
  if (gasValue > dangerThreshold) {
    Serial.println(" | DANGER!");
    digitalWrite(buzzer, HIGH);
  } else if (rate > 20) {
    Serial.println(" | WARNING!");
    digitalWrite(buzzer, HIGH);
    delay(200);
    digitalWrite(buzzer, LOW);
  } else {
    Serial.println(" | SAFE");
    digitalWrite(buzzer, LOW);
  }
  
  prevGas = gasValue;
  delay(1000);
}

int gasSensor = A0;
int buzzer = 8;
int prevGas = 0;
int dangerThreshold = 400;

void setup() {
  Serial.begin(9600);
  pinMode(buzzer, OUTPUT);
  Serial.println("PRAHAR System Active...");
}

void loop() {
  int gasValue = analogRead(gasSensor);
  int rate = gasValue - prevGas;
  
  float ttd = 0;
  if (rate > 0) {
    ttd = (dangerThreshold - gasValue) / (float)rate;
  }
  
  Serial.print("Gas: ");
  Serial.print(gasValue);
  Serial.print(" | Rate: ");
  Serial.print(rate);
  Serial.print(" | TTD: ");
  Serial.print(ttd);
  Serial.print(" sec");
  
  if (gasValue > dangerThreshold) {
    Serial.println(" | *** DANGER! ***");
    digitalWrite(buzzer, HIGH);
  } 
  else if (rate > 0 && ttd < 10) {
    Serial.println(" | !! WARNING — TTD < 10 sec !!");
    digitalWrite(buzzer, HIGH);
    delay(200);
    digitalWrite(buzzer, LOW);
  } 
  else {
    Serial.println(" | SAFE");
    digitalWrite(buzzer, LOW);
  }
  
  prevGas = gasValue;
  delay(1000);
}

// ============================================
// PRAHAR v3.0 — Predictive Gas Safety System
// By: Shivani singh | Chemical Engg Student
// Innovation: TTD Prediction Algorithm
// Made in India. For India.
// ============================================

int gasSensor = A0;
int buzzer = 8;
int redLED = 7;
int yellowLED = 6;
int greenLED = 5;

int prevGas = 0;
int dangerThreshold = 400;
int warningThreshold = 250;

void setup() {
  Serial.begin(9600);
  pinMode(buzzer, OUTPUT);
  pinMode(redLED, OUTPUT);
  pinMode(yellowLED, OUTPUT);
  pinMode(greenLED, OUTPUT);
  Serial.println("PRAHAR v3.0 — System Ready");
  Serial.println("Predictive Gas Safety System");
}

void loop() {
  int gasValue = analogRead(gasSensor);
  int rate = gasValue - prevGas;

  // TTD Calculation (core innovation)
  float ttd = 0;
  if (rate > 0) {
    ttd = (float)(dangerThreshold - gasValue) / rate;
  }

  // Serial Monitor Output
  Serial.print("Gas PPM: ");
  Serial.print(gasValue);
  Serial.print(" | Rate: ");
  Serial.print(rate);
  Serial.print(" | TTD: ");
  if (rate > 0 && gasValue < dangerThreshold) {
    Serial.print(ttd);
    Serial.println(" seconds");
  } else {
    Serial.println("N/A");
  }

  // DANGER Zone
  if (gasValue > dangerThreshold) {
    Serial.println(">>> DANGER! Gas Critical!");
    digitalWrite(redLED, HIGH);
    digitalWrite(yellowLED, LOW);
    digitalWrite(greenLED, LOW);
    digitalWrite(buzzer, HIGH);
  }

  // EARLY WARNING — TTD < 10 seconds
  else if (rate > 0 && ttd < 10 && ttd > 0) {
    Serial.println(">>> EARLY WARNING! Danger in ");
    Serial.print(ttd);
    Serial.println(" seconds!");
    digitalWrite(redLED, LOW);
    digitalWrite(yellowLED, HIGH);
    digitalWrite(greenLED, LOW);
    digitalWrite(buzzer, HIGH);
    delay(200);
    digitalWrite(buzzer, LOW);
  }

  // WARNING Zone
  else if (gasValue > warningThreshold) {
    Serial.println(">> WARNING! Gas Rising!");
    digitalWrite(redLED, LOW);
    digitalWrite(yellowLED, HIGH);
    digitalWrite(greenLED, LOW);
    digitalWrite(buzzer, LOW);
  }

  // SAFE Zone
  else {
    Serial.println("> SAFE — Monitoring...");
    digitalWrite(redLED, LOW);
    digitalWrite(yellowLED, LOW);
    digitalWrite(greenLED, HIGH);
    digitalWrite(buzzer, LOW);
  }

  prevGas = gasValue;
  delay(1000);
}

Credits

Shivani Singh

1 project • 0 followers

Chem Engg Student | Arduino Developer | Built PRAHAR — Gas Safety System with TTD Algorithm | Made in India.

PRAHAR – Predictive Industrial Gas Safety System

Things used in this project

Hardware components

Software apps and online services

Hand tools and fabrication machines

Story

Schematics

PRAHAR_Gas_Detection_Simulation

PRAHAR v3.0 — Gas Danger Prediction | Green

PRAHAR v3.0 — Circuit Design | Arduino

PRAHAR_Complete_Demo

PRAHAR_Danger_Alert

PRAHAR_Live_Demo

"PRAHAR Real Hardware Demo — Gas Detection & Danger Alert"

PRAHAR Safe Mode — Normal Gas Level Detected

Code

PRAHAR_TTD_Gas_Detection

PRAHAR_TTD_Upgraded_Code

PRAHAR_v3_LED_TTD_Prediction

Credits

Shivani Singh

Comments

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PRAHAR – Predictive Industrial Gas Safety System

PRAHAR – Predictive Industrial Gas Safety System

Things used in this project

Hardware components

Software apps and online services

Hand tools and fabrication machines

Story

Schematics

PRAHAR_Gas_Detection_Simulation

PRAHAR v3.0 — Gas Danger Prediction | Green

PRAHAR v3.0 — Circuit Design | Arduino

PRAHAR_Complete_Demo

PRAHAR_Danger_Alert

PRAHAR_Live_Demo

"PRAHAR Real Hardware Demo — Gas Detection & Danger Alert"

PRAHAR Safe Mode — Normal Gas Level Detected

Code

PRAHAR_TTD_Gas_Detection

PRAHAR_TTD_Upgraded_Code

PRAHAR_v3_LED_TTD_Prediction

Credits

Shivani Singh

Comments

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