Tag Intrinsically Safe

intrinsically safe

Intrinsically Safe

Intrinsically safe two-way radios are essential for certain environments.

Environments such as gas installations, where there is a potential risk of explosion.

Explosive atmospheres in the workplace include flammable gases, vapours, and flammable dust.

An example of where vapours can be dangerous is in a ships battery room.

Vapour emitted from charging batteries, produces potentially flammable vapour.

Vapour can ignite, causing damage and potential loss of life.

Conventional walkie talkies pose a small potential risk of causing a spark.

A spark could result in an explosion.

The Dangerous Substances and Explosive Atmospheres Regulations 2002 (DSEAR) places duties on employers to eliminate or control the risks from explosive atmospheres in their workplace.

What is an explosive atmosphere according to DSEAR?

DSEAR defines an explosive atmosphere as a mixture of dangerous substances mixed 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.

Atmospheric conditions are commonly referred to as ambient temperatures and pressures. That is to say temperatures of –20°C to 40°C and pressures of 0.8 to 1.1 bar.

What is ATEX?

ATEX is two European directives on controlling potentially explosive atmospheres.

1) Directive 99/92/EC (also known as ‘ATEX 137’ or the ‘ATEX Workplace Directive’) covers the minimum requirements for improving the health and safety protection of workers potentially at risk from explosive atmospheres. 

2) Directive 94/9/EC (also known as ‘ATEX 95’ or ‘the ATEX Equipment Directive) on the approximation of the laws of Members States concerning equipment and protective systems intended for use in potentially explosive atmospheres. 

The EU ATEX directives still currently apply to the UK.

ATEX intrinsically safe radios are available to meet the directive requirements.

ATEX radios are specially sealed to stop the risk of a spark causing an explosion.

Challenge of Installing IOT Sensor Equipment in Explosion Proof Areas

Challenge of Installing IOT Sensor Equipment in Explosion-Proof Areas, by Craig Miles

IoT, or the Internet of Things is already changing the way that businesses function, and this is set to explode in the forthcoming years.

IoT is all about improving business efficiency by collecting information (via sensors) about the physical world (Inputs such as temperature, pressure, location, etc), and then using this data to trigger an automated action, based on the data.

Installing the sensors that provide the ‘inputs’ to your IoT system is usually fairly straightforward in most environments, however potentially explosive environments require special considerations.

When installing any electrical or electronic device in a potentially explosive environment, the device must be rated as ‘EX’ , also known as ‘intrinsically safe’.

Intrinsically safe electrical equipment is available as components such as electric fans, cable glands, and hand-held two-way radios.

This is a business opportunity for IoT device manufacturers to create ‘EX’ rated sensors.

The main thing to consider at all times when designing your install is will my equipment cause a spark, potentially causing an explosion.

First, consider your sensor itself. An example is a sensor located in a ship’s battery room to monitor and report on voltage and a specific gravity of the lead-acid batteries, used for emergency backup.

The sensor you use to collect the information MUST be EX rated / intrinsically safe, to be compliant.

The next consideration is how you are going to get the data from the sensor ‘out’ of the potentially explosive area and to the location where the data is processed.

Wireless technologies such as Zigbee, WIFI, and LORA could be used, but by definition produce RF radiation which could potentially cause an explosion. Therefore it is crucial that only equipment that is EX rated is used.

In the case of environments hostile to RF (Radio Frequency) Radio Waves, such as ships, oil rigs, and other buildings with high metal content, an alternative would be a fixed wired solution.

When using wired methods to transmit sensor data, the cable gland must be designed so that the explosive area remains gas-tight, to prevent explosive gases from interacting with electrical components outside the intrinsically safe area.

Glands for this purpose exist and can be found online.

To conclude, the key to installing the Internet of Things (IOT) in a potentially explosive environment is to ensure that every piece of IoT equipment that is installed is EX rated to prevent explosion risks.

You also need to think about and ensure that any wiring that leaves the intrinsically safe/explosive area goes through properly rated EX glands, to ensure safety.

For more information on the Challenge of Installing IOT Sensor Equipment in Explosion-Proof Areas, why not contact us.

The author is Craig Miles (me) and I can be contacted via www.craigmiles.co.uk

All content is copyright, and copying and all rights are reserved (c) Craig Miles 2015

Internet of Things | Two Way Radio Wireless Communications – Yesway Communications