Hazardous Area Analyzers

In many industrial facilities, combustible or explosive gases may be present as part of normal operations. These locations are classified as hazardous areas, meaning that any electrically powered equipment installed there must be specifically designed so it does not become an ignition source. A standard analyzer placed in such an environment could generate sparks, heat, or electrical faults that might ignite an explosive gas mixture.
Hazardous area analyzers are gas analysis systems that are engineered for safe operation within classified locations, where flammable or explosive atmospheres may exist. These analyzers are designed to measure process or sample gases while ensuring that the analyzer itself does not pose a risk to the surrounding environment.
For over four decades, Nova Analytical Systems has been a trusted provider of precision gas analysis technology. We design and manufacture advanced analyzers specifically configured for installation in hazardous and classified areas, delivering dependable performance, long-term reliability, and safe operation in demanding industrial environments.

Benefits
Benefits of Hazardous Area Analyzers

Nova’s hazardous area analyzers are built to operate safely and reliably in classified locations where combustible gases may be present. Key benefits include:
- Safe operation of gas analysis equipment in hazardous environments
- Compliance with hazardous area classifications (Class I, Division 1 & 2, or Zones 1 & 2)
- Protection against ignition sources caused by electrical or electronic components
- Robust designs suitable for harsh industrial conditions
- Long service life with minimal maintenance
- Flexible configurations to suit a wide range of process applications
Applications
Applications of Hazardous Area Analyzers

Nova hazardous area analyzers are used in a wide range of industries where gas analysis is required within classified locations, including:
- Oil and gas
- Chemical and petrochemical processing
- Power generation
- Steel and metal processing
- Manufacturing
- Agriculture
- Landfills
Offerings
Nova’s Hazardous Area Analyzer Offerings and Capabilities

Nova Analytical Systems designs hazardous area analyzers for safe installation and operation within classified locations, while providing accurate and reliable process gas analysis. These systems allow critical gas measurements to be performed directly within hazardous areas without compromising safety.

To meet hazardous location requirements, Nova analyzers are configured using proven protection methods appropriate to the application and area classification, including:
- Explosion-proof enclosures. Designed to contain any internal ignition and prevent flame or pressure from escaping to the surrounding atmosphere.
- Purged cabinets. Use purge and pressurization systems to maintain positive internal pressure and prevent the ingress of explosive ambient gases.
Nova hazardous area analyzers can be configured to measure a wide range of gases, including:
- Oxygen (O₂)
- Carbon monoxide (CO)
- Carbon Dioxide (Cl₂)
- Methane (CH₄)
- Hydrogen (H₂)
Expansion-Proof Cabinets
Explosion-Proof Cabinets

For Class 1 Division 1 applications, we frequently offer a NEMA 7 explosion-proof cabinet. The cabinet itself is a heavy cast aluminum box with mounting feet. There may be a threaded solid metal cover or there may be a windowed cover through which the controls are magnetically operated. The gas entry and exit points of the analyzer will have flame/flash arrestors, and the wire entries must be protected with a properly-installed EYS seal.

There are a few ways of configuring these analyzers, as shown below.

a) Explosion-proof cabinet with detector and local display
b) Explosion-proof detector cabinet with rack-mount control cabinet
c) Explosion-proof detector cabinet with explosion-proof control cabinet
d) Explosion-proof detector cabinet with NEMA 4 wall-mount control cabinet

With a) and c), the complete system may be installed in the hazardous area. With b) and d), only the detector cabinet is installed in the hazardous area. The control cabinets are suitable for non-hazardous areas only and are typically installed in a control room nearby.

Due to the size constraints of the ex-proof cabinets we use, these analyzers are usually suitable for analysis of only one gas in a sample that is clean and dry. Our most popular models are:
Purged Cabinets
Purged Cabinets

Another way of meeting hazardous area requirements is to install a positive pressure purge system on the analyzer cabinet, as shown below. This might be a suitable alternative to an explosion-proof cabinet when more than one gas is to be analyzed, or the sample gas requires additional sample conditioning prior to analysis. These situations require a larger wall-mount cabinet that is not inherently suitable for hazardous areas.

A purge system uses a supply of instrument air or inert gas, such as nitrogen, to perform two phases of explosion protection.
1. An initial purge process removes any potentially explosive atmospheres from the enclosure.
2. After the initial purge, sufficient compressed air or inert gas is supplied to maintain a constant positive pressure inside the analyzer cabinet. The cabinet will likely have outgoing leaks. The purge system monitors pressure in the cabinet and ensures that it remains above the surrounding ambient pressure to prevent ingress of potentially explosive atmospheres.
A positive pressure system is suitable for integration with equipment that is not intended for use in hazardous areas. The positive pressure system allows the equipment to be installed and operated in the hazardous area.

These systems require a supply of instrument air or inert gas to function.

In most cases, any gas analyzer that can be built into our standard NEMA 4 cabinet can have a positive pressure purge system installed onto it.

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Hazardous Area Analyzers

Benefits of Hazardous Area Analyzers

Applications of Hazardous Area Analyzers

Nova’s Hazardous Area Analyzer Offerings and Capabilities

Explosion-Proof Cabinets

Purged Cabinets