Industrial Gas Detectors – Choosing the Right Gas Detection Solution

Industrial gas detection is one of the most important layers of protection in modern facilities. Whether monitoring toxic gases, oxygen deficiency, carbon dioxide, combustible gases, or specialty process gases, a properly selected gas detector helps protect personnel, equipment, and production processes while ensuring compliance with safety regulations.

Today, fixed gas detection systems are widely used in manufacturing plants, wastewater treatment facilities, laboratories, battery rooms, chemical plants, power stations, pharmaceutical facilities, food processing plants, refrigeration systems, semiconductor production, hydrogen applications, and many other industries.

The first step in selecting the right detector is understanding the application.

Stand-Alone Gas Detectors

Stand-alone gas detectors are ideal when a single monitoring point is required without installing a complete gas detection controller.

These detectors operate independently and provide immediate local alarms whenever gas concentrations exceed the programmed alarm levels.

A typical stand-alone detector includes:

• Audible alarm
• Bright LED status indicators
• Dry contact relay output
• TEST and RESET functions
• Optional connection to an external siren and beacon

Because the detector is factory calibrated, installation is simple—connect the power supply and the detector is ready for operation.

TOC-750BAV Stand-Alone Gas Detector

The TOC-750BAV is designed for continuous industrial gas monitoring and is available with sensors for:

• Combustible gases (0–100% LEL), including hydrogen, methane, LPG, and many other flammable gases
• Oxygen (O₂)
• Carbon Monoxide (CO)
• Carbon Dioxide (CO₂)
• Hydrogen Fluoride (HF)

Key features include:

• Dry contact relay output
• Built-in audible alarm
• Power, Alarm, and Fault LED indicators
• Integrated TEST and RESET button
• Optional external sounder and warning beacon
• Factory calibrated
• Extremely long sensor life of 5–10 years
• Manufactured in the United Kingdom
• Operating voltage: 12–28 VDC
• Response time: approximately 10 seconds
• IP54 enclosure

Analog 4–20 mA Gas Detectors

Many industrial facilities already use PLC, DCS, or Building Management Systems (BMS).

For these applications, gas detectors with a standard 4–20 mA analog output provide a simple and reliable method for transmitting real-time gas concentration data to the control system.

TOC-30 Analog Gas Detector

The TOC-30 is available for monitoring:

• Oxygen (O₂)
• Carbon Monoxide (CO)
• Nitric Oxide (NO)
• Nitrogen Dioxide (NO₂)
• Ammonia (NH₃)
• Chlorine (Cl₂)
• Ozone (O₃)
• Sulfur Dioxide (SO₂)

Additional sensor options are available upon request.

Addressable Gas Detectors

Large facilities often require dozens of gas detectors installed throughout the site.

Addressable detectors simplify installation by allowing multiple detectors to communicate with the controller using only a two-wire communication cable.

This significantly reduces wiring costs while allowing every detector to be individually identified and monitored.

TOC-750 Addressable Detector

The TOC-750 supports a wide variety of gas sensors, including:

• Carbon Monoxide (CO)
• Carbon Dioxide (CO₂)
• Oxygen (O₂)
• Hydrogen Sulfide (H₂S)
• Hydrogen (H₂)
• Ammonia (NH₃)
• Hydrogen Chloride (HCl)
• Hydrogen Cyanide (HCN)
• Ethylene Oxide (ETO)
• Nitric Oxide (NO)
• Nitrogen Dioxide (NO₂)
• Sulfur Dioxide (SO₂)
• Volatile Organic Compounds (VOC)
• Formaldehyde
• Ethylene
• Phosphine
• Silane
• Chlorine
• Hydrogen Bromide
• Hydrogen Fluoride
• Combustible gases (Pellistor or Infrared)
• Many additional specialty gases

Gas Detection in Hazardous (ATEX) Areas

Applications involving flammable atmospheres require equipment specifically designed for hazardous locations.

ATEX-certified detectors are commonly used in:

• Oil and gas facilities
• Chemical plants
• Hydrogen installations
• Refineries
• Fuel storage terminals
• Biogas plants
• Solvent storage areas
• Paint manufacturing
• Pharmaceutical production

These detectors are designed to operate safely in explosive atmospheres while providing continuous gas monitoring.

TOC-903 Explosion-Proof Gas Detector

The TOC-903 combines:

• ATEX-certified explosion-proof enclosure
• 4–20 mA output
• Two alarm relays
• Digital display
• Wide selection of electrochemical, catalytic, infrared, and PID sensors

TOC-750X Addressable ATEX Detector

For large hazardous-area installations, the TOC-750X combines addressable communication with ATEX certification, making it suitable for multi-detector systems installed in explosive environments.

TOC-102 Analog ATEX Detector

Facilities using conventional analog control systems can utilize the TOC-102, which combines:

• Explosion-proof construction
• 4–20 mA analog output
• Support for numerous toxic, combustible, oxygen, and specialty gases

SF₆ Gas Detection

Electrical substations and high-voltage switchgear frequently use sulfur hexafluoride (SF₆) as an insulating gas.

The addressable SF₆ detector provides continuous monitoring from 0–1,000 ppm, allowing early detection of gas leaks while integrating directly into the gas detection controller.

Selecting the Right Gas Detector

Choosing the correct detector depends on several factors:

• Which gas needs to be monitored?
• What concentration range is expected?
• Is the installation in a hazardous (ATEX) area?
• Is a stand-alone detector sufficient, or is integration with a controller required?
• Is analog 4–20 mA communication needed?
• Would an addressable system simplify installation?
• Are local alarms required?
• Does the application require explosion-proof equipment?

Every industrial application has different requirements, and selecting the appropriate detector ensures reliable monitoring, improved safety, easier maintenance, and long-term system performance.

With a broad range of stand-alone, analog, addressable, and ATEX-certified detectors available for hundreds of industrial gases, gas detection systems can be tailored to virtually any industrial environment.