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 ships battery room to monitor and report on voltage and 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 high metal content, an alternative would be a fixed wired solution.

When using wired methods to transmit sensor data, the cable glanding must be designed so that the explosive area remains gas tight, to prevent explosive gases 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.

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

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