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Hazardous area products

With over 50 years’ industry experience, James Fisher Strainstall (JF Strainstall) is a leading supplier of hazardous area load monitoring solutions, including load cellsload shackles, and load pins, as well as full-scale asset monitoring systems.


What is a hazardous area?
Hazardous area zones explained
Hazardous area products
Case studies


What is a hazardous area? 

A hazardous area (also known as a potentially explosive atmosphere) is defined as an environment that consists of varied concentrations of flammable gases, vapors, mists or combustible dusts. They are defined in DSEAR as "any place in which an explosive atmosphere may occur in quantities such as to require special precautions to protect the safety of workers". In this context, 'special precautions' is best taken as relating to the construction, installation and use of apparatus, as given in BS EN 60079 –10. Where these elements are present, all equipment installed in such environments is specially designed and tested to meet a range of requirements that together ensure the safety of personnel and avoid potentially dangerous situations resulting from the equipment’s reaction to its surroundings.

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What is an explosive atmosphere? 

An explosive atmosphere is defined as a mixture of dangerous substances with air, under atmospheric conditions, in the form of gases, vapours, mist or dust in which, after ignition has occurred, combustion spreads to the entire unburned mixture. 

What is ATEX/IECEx? 

ATEX ratingAtmosphères Explosives Directive 2014/34/EU of the European Parliament and of the Council of 26 February 2014 on the harmonisation of the laws of the Member States relating to equipment and protective systems intended for use in potentially explosive atmospheres. 

IEC: The International Electrotechnical Commission is the international standards and conformity assessment body for all fields of electrotechnology.  

Hazardous Area Certification IECEx 

IECEx: This is a voluntary system which provides an internationally accepted means of proving compliance with IEC standards. IEC standards are used in many national approval schemes and as such, IECEx test reports and certification can be used to support national compliance, negating the need in most cases for additional testing. 

E.g. IECEx test report for the type 7713 load pin was provided to KOSHA (Korean notified body) who issued a Kosha certificate based only on the findings of the IECEx report. 

Both ATEX and IECEx certificates comply with the IEC 60079 series of standards. 

IEC 60079: This series of standards is globally accepted. There are a number of other legacy standards in some countries. These are being phased out and replaced by the IEC 60079 series. 

There are four countries in the world that have written IECEx into their national legal requirements as an accepted alternative to the national certification: 

  • Australia 

  • New Zealand 

  • Singapore 

  • India 

What are the requirements for ATEX/IECEx load cells? 

To comply with the ATEX Quality Assurance Notification (QAN) and IECEx Quality Assurance Report (QAR) JF Strainstall undergo an audit by SGS Baseefa every 18 months. This is an extensive audit and covers all aspects of the business covered by our ISO 9001:2015 and specifically for the certified products EN 80079-34:2011. 

NA Audits (USA and Canada) 

JF Strainstall is audited by SGS Baseefa on behalf of SGS Suwanee four times a year. These are product-based audits on certified products manufactured since the last audit. 



Hazardous area zones explained 

Hazardous areas are classified in terms of zones on the basis of the frequency and duration of the occurrence of an explosive atmosphere. 

For gases, vapours and mists the zone classifications are: 

Zone 0 

A place in which an explosive atmosphere consisting of a mixture of dangerous substances in the form of gas, vapour or mist is present continuously or for long periods frequently. 

Zone 1 

A place in which an explosive atmosphere consisting of a mixture of dangerous substances in the form of gas, vapour or mist is likely to occur in normal operation occasionally. 

Zone 2 

A place in which an explosive atmosphere consisting of a mixture with air of dangerous substances in the form of gas, vapour or mist is not likely to occur in normal operation but, if it does occur, will persist for a short period only. 

The hazardous area zone classification and corresponding equipment categories are: 

Zone 0 - category 1 equipment 

Zone 1 - category 2 equipment 

Zone 2 - category 3 equipment 

Note: Category 1 equipment can also be used in zones 1 and category 1 and 2 equipment can be used in zones 2. 

Hazardous area zones explained - An infographic to explain what constitutes a hazardous area zone using a petrol station as an example. The gas truck and gas tank are zone 0, the hose transferring gas from the truck to the tank is zone 1 and the surroundi


North America (NA) - US and Canada – Hazardous Location (HazLoc) 

Division and Zone classification systems 

The National Electric Code (NEC), NFPA 70,[4] as published by the National Fire Protection Association, defines area classification and installation principles. The principles of the NEC Division and Zone classification systems are applied in countries such as in the United States and Canada. 

Specifically, Article 500 describes the NEC Division classification system, while Articles 505 and 506 describe the NEC Zone classification system. The NEC Zone classification system was created to provide multinational companies with a system that could be harmonized with IEC classification system and therefore reduce the complexity of management. 

Class I, Division 1 classified locations 

An area where ignitable concentrations of flammable gases, vapours or liquids can exist all of the time or some of the time under normal operating conditions. A Class I, Division 1 area encompasses the combination of Zone 0 and Zone 1 areas. 

This marking would include: Class, Division, Gas Group(s), Temperature Classification 

Class I, Division 2 classified locations 

An area where ignitable concentrations of flammable gases, vapours or liquids are not likely to exist under normal operating conditions. In this area the gas, vapour or liquids would only be present under abnormal conditions (most often leaks under abnormal conditions). A Class I, Division 2 area encompasses Zone 2 areas. 

 Hazloc classification 

 Hazardous area zone classification equivalent  

 Class I, Division 1 

 Zone 0 & Zone 1 

 Class I, Division 2 

 Zone 2 



Hazardous area vs. Explosion proof  

As they are both designed for safe use in flammable environments, hazardous area certified equipment is often confused with explosion-proof devices. However, the way that they increase safety differs significantly. While hazardous area certified equipment minimises the chance of any ignition within its design or circuitry, explosion-proof equipment contains potential detonations within an enclosure, sealing it away from the flammable environment. It is important to note that explosion-proof equipment is not designed to be resistant to external explosions. 


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Hazardous area products 

ATEX and IECEx certified load monitoring products 

JF Strainstall can design and manufacture load measurement equipment to suit your specific requirements. The company’s hazardous area products are certified by SGS Baseefa - the leading, internationally recognised certification body for explosion protected equipment, delivering IECEx, ATEX and DSEAR standards to customers operating in challenging environments worldwide.


Benefits of JF Strainstall's hazardous area products:  Available options: 
Designed and manufactured in the UK for high-quality assurance   Cabled and wireless options 
Robust construction for use in hostile environment  Environmentally sealed to IP67 or IP68 
Easy to install, highly accurate and reliable   Can be used singularly or as part of system 
Long design life with corrosion protection  All load ratings available
Bespoke solutions tailored to your specific needs  
Supplied with certification for turn-key use  


JF Strainstall's hazardous area load cell amplifiers deliver a stronger signal between load cells and load indicators for applications in hazardous areas. 

Designed for ease of installation and commissioning, JF Strainstall's amplifiers are used where a robust signals is required or a longer distance transmission is needed between the load indicators and the load cells. 

The amplifiers can be housed in a variety of enclosures to suit different applications, either singly or included in a large enclosure for multiple load cell use. Our DIN rail mounted 2506 load cell amplifier also includes IECEx certification. 

The 2506 amplifiers are available in two versions, namely the 2506A for full-bridge strain gauge inputs from sensors such as load cells and pressure transducers, and the 2506B for quarter or half-bridge strain gauge elements  - which may be used in structural measurements. 


Intrinsically safe: 

The intrinsically safe 4-20mA internal amplifier is a programmable 2-wire loop powered amplifier which provides the additional features of temperature compensation and linearisation.

Benefits of JF Strainstall’s hazardous area amplifiers:  Features of hazardous area amplifiers: 
Designed and manufactured in the UK for high quality assurance   Quarter, half or full bridge strain gauge amplifiers
Robust construction for use in hostile environments   Various industrial standard outputs 
Easy to install, highly accurate and reliable  24V DC supply 
Supplied with certification   
Provides a robust signal between load indicator and load cell  

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JF Strainstall’s hazardous area load cells are highly accurate, delivering greater stability and reliability to support customer operations in hazardous areas. 

JF Strainstall supply a wide range of hazardous area load cells, including compressiontension and shear options. Ranging in rated capacity from 10kgs to 3,000 tonnes and above, JF Strainstall can design and commission a solution to meet the requirements of your  specific application. 

The company’s hazardous area load cells can be supplied with either suitable Zener barriers or Exm (encapsulated) that can connect directly to the safe area without the need for any additional interface. 

All JF Strainstall products are certified to ATEX EN 60079 and IECEx IEC 60079 and are supplied with full environmental protection, hazardous area certification and a certificate of calibration. For a load cell to be considered hazardous area certified, it must mitigate the chance of ignition in all elements of its design. The tolerance level for this heightens depending on the device’s zone classification. 

Benefits of Strainstall’s hazardous area load cells:   Features of hazardous area load cells: 
High accuracy  Manufactured from stainless steel or high tensile aluminum 
Greater stability and reliability   High degree of protection against dust and water 
Life expectancy of 20+ years  For use in Zone 0, 1 and 2 hazardous areas
Easy to install and use  


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1 2506* Amplifier System  

2 Load Transmitter Type 7935  

3 Line Amplifier Type 5573E  

4 Series 5572 Load Transmitter  

5 Series 5573 Load Transmitter  

6 Load Transmitters Type 9247A/B and 9248A/B  

7 Wireless Handset Type 10190  

8 Wireless Interface Unit Type 10324  

9 Wireless Loadcell Type 10356 Aluminium Tension Link  

10 Type 5713 Load Pin  

11 Type 6000 Solenoid  

12 A Range of Loadcells Type 7713 LMP 7714 COM 7715 DIA  

13 Load Transmitter Pin Type 11103  

14 UHF Antenna Type 8780  

15 Wireless Receiver Unit Type 10858  

16 Wireless Receiver Unit Type 10379  

17 Multi-Channel Strain Gauge Interface Junction Box Type 9744  

18 Wireless Handset Type 9978  

19 Wireless Loadcell Type 9979  

20 Wireless Interface Unit Type 10323