Industrial Client ProjectCompleted

Industrial Gas Detection Device Development

Continuous monitoring of toxic and explosive gases in industrial environments is both a workplace safety requirement and a critical engineering challenge for managing operational risk. In this project, HEFA Teknoloji A.Ş. developed industrial gas detection hardware and embedded firmware capable of detecting toxic gases (CO, H₂S, NO₂, NH₃, etc.) and explosive gases (methane, butane, hydrogen, LPG, etc.) for a client's OEM needs.

What We Built

Hardware Design

  • Electrochemical sensors (high-selectivity detection at ppm levels for CO, NO₂, NH₃, H₂S)
  • Pellistor (catalytic) sensors (LEL measurement for CH₄, LPG and flammable gases)
  • Signal conditioning circuit (noise filtering and MCU interfacing)
  • 4-20mA communication circuit (low-loss over long cable distances)
  • PCB design (mixed-signal layout compliant)

Embedded Firmware

  • Sensor filtering, regression equations, calibration functions, communication protocols and alarm algorithms
  • Two independent alarm thresholds (Alarm 1/Alarm 2)
  • EEPROM-based calibration coefficient and device configuration storage

Output Interfaces

  • 4–20 mA (IEC 60381-1) and RS485 Modbus RTU (IEC 61158)

Technical Specifications

ParameterValue
Measured gasesCO, NO₂, NH₃, H₂S and flammable gases
Sensor technologyElectrochemical, Pellistor
Output protocols4–20 mA, RS485 Modbus RTU
Alarm channels2 independent thresholds (configurable)
Power supply12–24 V DC

Use Cases

  • Industrial Facilities and Factories — Paint/solvent production, chemical plants, power plants, food industry ammonia cooling
  • Petrochemical and Refinery — H₂S and LEL monitoring, pipeline, pump rooms

Frequently Asked Questions

Can a single device measure multiple gases simultaneously?
The current design optimises each device for one primary gas type. For multi-gas monitoring, the recommended architecture is deploying multiple addressable devices over the same RS485 bus.
How resistant are pellistor sensors to silicone poisoning?
Pellistor sensors can suffer sensitivity loss from silicone compounds, sulphur compounds and some solvents. For environments with high silicone concentrations, electrochemical or NDIR-based alternatives should be considered.
Can 4–20 mA and Modbus outputs be active simultaneously?
Yes. Both outputs are designed to operate independently and simultaneously.
How is the device integrated into an existing SCADA system?
RS485 Modbus RTU is a standard protocol supported by all modern PLCs and SCADA systems. The device can be integrated using its Modbus register map and communication parameters.
What is the recommended calibration interval?
A 6–12 month interval is recommended for electrochemical sensors. For pellistor sensors, 3–6 months depending on site conditions.

This project covers the full hardware-firmware development cycle: from sensor selection and characterisation to analog signal conditioning, embedded calibration algorithms and industrial communication protocol implementation. If you have a gas detection device development need — whether a new design or revision of an existing device — we can evaluate your technical requirements together. gas detection device design service for more information.

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