Today, the rugged tablet is commonly used across sectors like manufacturing, oil and gas, healthcare, defense, energy/utilities and more. One key performance parameter in these environments is ingress protection (IP) rating – resistance to ingress of dust and water into the device. For business-critical operations, the best rule of thumb is to always err on the side of caution and choose a rugged tablet with at least an IP67 rating. Most companies will ask why this is the case, and the answer lies in an understanding of the IP rating system and what protection an IP67 rated device will bring.
Although we’ve discussed the importance of IP67 or IP68 rating for a rugged tablet, many businesses miss the importance of having a device that is purpose built and tested for this rating. Although many manufacturers of add-on protective outer cases say that their products will protect the average consumer-grade OEM Android tablet in the same way, that is only potentially true under narrowly defined parameters and may require user cooperation.
Revisiting the Practicality of IP Ratings
The International Electrotechnical Commission (IEC) is the organization that sets the international standards and assessment for electrotechnology fields. The IEC ingress protection (IP) rating, governed by standard IEC 60529, is made up of the first digit which indicates its resistance to solids like dust, and a second digit that indicates its resistance to water. The higher the ratings numbers earned by a device the greater the ingress protection. A summary of the ingress protection ratings is located here.
In the IP rating, the solid ingress rating indicates the maximum diameter of solid particles that can enter the device. For example, a solid ingress rating of 4 indicates a maximum entry diameter of 1 mm – protection from large objects but no protection from dust and dirt particles that can enter the device at connection and seal points around screens and other areas. A rating of 6, the maximum, indicates complete protection against “harmful” dust or dirt seeping into the unit after being in direct contact with the matter for eight hours or more, under vacuum. Field service, manufacturing, and industrial environments will all naturally have a high degree of dust and dirt, so the high rating of 6 in the IP67 rating is a must have.
The water ingress rating is highly variable. Lower numbers (1 to 3) indicate protection against dripping or spraying from certain directions. Level 4 indicates protection from splashes from any direction. A rating of 4 might seem adequate in many circumstances. However, high powered directional sprays or immersion of the device within a liquid, even if unlikely, will be destructive to electronics. Therefore higher liquid ingress ratings (such as 5, 6, or 7) are critical for reliable tablet operation in deployed or mission critical circumstances. A rating of 7 is earned by a device capable of being submerged under water for 30 minutes at a depth of 1 m without adverse operational effects. It may seem like the higher rating of 7 would be unnecessary for anyone not working around large amounts of water on a regular basis, but that is the wrong way to look at it.
The Business Case for an IP67 Rated Rugged Tablet
First it’s important to understand that consumer devices typically have a rating of IP42 or lower. A consumer grade tablet with a case may offer additional protection from dust and resistance to other solids as well as fluids, but the protection is nominal. This is in stark contrast to a rugged tablet that is built from the component level up with protection for internal components such as sealed connectors, membranes protecting speakers and microphones, gaskets for packaging, and more.
Tablets utilized for business operations must work reliably in whatever environment is encountered. Some industries, such as oil and gas or mining, inherently operate in dusty and wet environments. Other industries operate outdoors in typically more tame environments, but can still encounter days where high levels of pollen, rain, and other challenges arise. And being operated by humans, the tablet may be dropped into a puddle of water. Many sectors regularly deal with liquids in large amounts as part of different processes that can create conditions where a device is subject to conditions like submersion. Regardless, the tablet must operate through these challenges and get the job done.
Many businesses approach a device purchase from the standpoint of the minimum acquisition cost of a commercial grade OEM Android tablet or Windows tablet that is not purpose built to gain an IP67 rating, and assume that adding a protective cover will ruggedize the tablet. However, these covers may not fully protect the tablet. First, improper installation or wear over time may not offer full protection, particularly from liquids. Second, some critical external interfaces, such as a USB connector, may require the user to press a cover into the connector to provide protection. Third, speakers, microphones, cameras, and other sensors provide ingress paths if not properly accommodated. If the user forgets, both dust and liquid ingress can occur. It only takes one incident to blow that cost savings in terms of total cost of ownership (TCO) due to the need for expensive replacement or repair, plus the critical down time when the tablet fails.
As with all field service buying decisions, it’s a question of ensuring the selected rugged tablet is purpose built to be reliable, user-friendly, and able to cope with the demands of the user and the possible variables of the environment. Whether you choose a rugged Android tablet or Windows tablet, calculations of costs must factor in environmental conditions that are potentially rare and extreme.
A rugged tablet designed with an IP67 rating utilizes connectors, gaskets, seals, and other techniques such that the device is impenetrable by dust and submersible to 1 m in water without the need for an outer cover. IP67 rated connectors do not require the user to install a cover. Cameras are sealed with cover glass or plastic with a gasket. Speakers and microphones are protected by membranes that allow for sound transmission while providing ingress protection. This is the most reliable scenario, being designed into the tablet itself.
The prudent and best business decisions in highly variable environments is to weigh in the reality of dirt, dust and moisture ingress that will invariably shorten the life of a commercial tablet with a low IP rating. It’s clear that any business sector needing a rugged tablet will get the longest life, best performance, lowest TCO and highest return on investment (ROI) from a rugged tablet with an IP67 rating.
