Understanding the Ruggedness of Mobile Devices

cell-phone-in-water

Mobile technology has taken quite a leap in terms of evolution. As technology advances, we are able to put more and more power into these handheld beauties that we “used” to use to make calls, which are now used to do virtually everything, including serving as a credit card thanks to the wonders of NFC. Dual cores, quad cores, and recently announced octo-core devices seem to be a dream taken straight out of The Jetsons, where technology is powerful enough to interact with us and become a day to day necessity, almost like an electronic extension of our bodies. However, much as with everything else, technology has a limitation which can render it useless in the blink of an eye. Mobile devices are not always impervious to the effects of mother nature, and as such, they can get easily damaged by something as basic to humanity as water and gravity. Tech manufacturers are well aware of this “deficiency” and have, for many years, been working on taking the elements out of the list of possible things that can hurt their products.

The military/defense oriented manufacturers have offered rugged hardware able to take serious beatings for a very long time. However, it was not until recently that this tech made its way into the consumer market, based essentially on the potential clumsiness of people. There are, nowadays, a wide array of devices that are presented as “rugged” or capable of withstanding elements such as rain, dust, elevated temperatures, and also capable of taking moderate to high levels of physical punishment. This is a great cure/remedy for the aforementioned clumsiness of the everyday consumer. Lets face it, how many times have you had your friend tell you that his/her phone decided to take a dive into a toilet, a cup of water/coffee, swimming pool? What about an issue that has plagued our devices since the very early days, which is dust “magically” appearing behind the screen? Accidents do happen, and getting a phone that fits your “lifestyle” could potentially save you from having to buy replacement devices often. But understanding the specifications could save you from making a costly mistake.

Most of the claims from manufacturers about protection levels for electronic devices are not simply made up. They are carefully studied and tested standards that are used during the manufacturing process of devices. These standard testing procedures are used to evaluate the devices in question to see if these can be certified under the rigorous standards. Some of the most commonly used standards for testing come from organizations such as ISONISTASTM, and several others. They provide manufacturers guides to follow for the manufacturing and testing of certain qualities and properties such as ingress of external contaminants, impact protection, etc. Certification is done by certain other agencies such as UL, CSA (for Canada), and many more, which make sure that these standards are met. Once these conditions are certified, products are given IP (ingress protection) ratings followed by numbers which denote their level of protection. So, the format for IP ratings looks like this:

IPXYZ

  • X= Solids Ingress Protection Level
  • Y= Liquids Ingress Protection Level
  • Z= Mechanical Impact Resistance

The third digit, which denotes the resistance against hitting it, is not displayed according to IEC60529. This is the standard to which enclosures for small electronics must adhere to. However, not showing in there does not mean that the test was not performed.

Dust Protection

As stated in an earlier example, dust can get under your screen. We have all seen this at one point or another with our electronics. It is almost inevitable since our devices operate with electricity. Thus, you will have some level of static that will attract dust onto the electrical components. This will find its way through the seals around the screen and into your device. But dust is not your only concern, as there are larger solids that can also get into your device that could damage key hardware components inside (salt, sand, etc). Protection against the ingress of solids into our devices can be categorized as follows:

 

IP First number – Protection against solid objects

0 No special protection
1 Protected against solid objects over 50 mm, e.g. accidental touch by persons hands.
2 Protected against solid objects over 12 mm, e.g. persons fingers.
3 Protected against solid objects over 2.5 mm (tools and wires).
4 Protected against solid objects over 1 mm (tools, wires, and small wires).
5 Protected against dust limited ingress (no harmful deposit).
6 Totally protected against dust.

 

Water-Proofing / Water Resistance

Quite possibly one of the most commonly known misconceptions in technology is that of water resistance. There are very few man-made tech apparati that can be considered to be fully waterproof.  Cell phones unfortunately are not among them. Having said that, in recent years, companies such as Motorola, Kyocera, and Sony (among a few others) have made devices that will comply more with a less stringent level of protection, water resistance. Before we go into the ratings themselves, it is worth mentioning that waterproof is something that is completely sealed off and will prevent the ingress of water under most/all conditions. Water resistance, on the other hand, means that the device is protected against the ingress of water to a certain degree. And as such, depending on the exposure to water, ratings are given to the various possible situations. All in all, a water resistant device is not waterproof, and making sure that you understand this difference can save you from having to replace your device since most manufacturers do not cover water damage under their limited warranties. Having said that, let’s take a look at the ratings:

 

IP Second number – Protection against liquids

0 No protection.
1 Protection against vertically falling drops of water e.g. condensation.
2 Protection against direct sprays of water up to 15o from the vertical.
3 Protected against direct sprays of water up to 60o from the vertical.
4 Protection against water sprayed from all directions – limited ingress permitted.
5 Protected against low pressure jets of water from all directions – limited ingress.
6 Protected against temporary flooding of water, e.g. for use on ship decks – limited ingress permitted.
7 Protected against the effect of immersion between 15 cm and 1 m for 30 minutes.
8 Protects against long periods of immersion under pressure.

 

Mechanical Impact Resistance

Aside from dropping your device(s) in puddles of water/washer/swimming pools/etc., one of the most common occurrences with mobile devices is the accidental drop or the (un)intended accidental meeting with walls, hammers, or other blunt objects. This test is fairly straightforward, it is tested to see how much “love” a device can take. It is measured in Joules, a unit of energy. Due to the fragile nature of most electronic devices in this day and age, it is assumed by the manufacturer that you will not test the device’s “time of flight” capability, nor that you will test if your glass screen is able to hold its own against a hammer. However, there are some devices out there that will provide (without the need for a second enclosure) some level of protection against possible mistreatment. The third digit (not depicted in the IP standard) conforms to the following testing criteria:

 

IP Third number – Protection against mechanical impacts

0 No protection.
1 Protects against impact of 0.225 joule
(e.g. 150 g weight falling from 15 cm height).
2 Protected against impact of 0.375 joule
(e.g. 250 g weight falling from 15 cm height).
3 Protected against impact of 0.5 joule
(e.g. 250 g weight falling from 20 cm height).
4 Protected against impact of 2.0 joule
(e.g. 500 g weight falling from 40 cm height).
5 Protected against impact of 6.0 joule
(e.g. 1.5 kg weight falling from 40 cm height).
6 Protected against impact of 20.0 joule
(e.g. 5 kg weight falling from 40 cm height).

 

Other common rugged factors

While the IP ratings are the ones that will protect against mostly everything, there are other things, not covered in the standard that are tossed around by manufacturers as “features.” For instance, one of the most commonly known ones (that we are used to anyways), is scratch resistant screens, which are made out of Gorilla Glass (a product developed by Corning). This glass is essentially regular aluminosilicate, but with chemical additions and coatings to boost some of its mechanical properties. The scratch resistance comes from a special, invisible coating on top of the actual glass that prevents light scratches from ever reaching the surface of the actual glass. While some of the other chemical additions actually do increase the mechanical strength of the glass by a little, Gorilla glass is not more resistant to impacts than its untreated sibling (regular glass). This is a big misconception that has been around as long as Gorilla glass where people believe that scratch resistance equates to impact resistance. Thousands of handsets are sent in for repairs by people who believe this to be the case.

Last but not least (and along the same lines as Gorilla Glass), is another misconception about glass strength: shatter resistance. The way this feature is presented is by calling it anti-shatter screen. The crux of this is that this is a bit of a fallacy. There is nothing special done to a screen deemed as “anti-shatter” other than a adding a special film, which will contain all the glass shards in case of screen breakage. This is the same technology used in car windshields. A coating gets added to the user-facing area of the glass, so that glass pieces do not pose a risk to the user in case of the glass breaking. What this film does not do is provide additional mechanical strength to the glass itself (well, maybe a bit, but certainly not enough to protect it from significant impacts).

I hope that this article is useful to some. If you see someone using their device as a prop for party tricks (“Hey look! I am going to hit my phone with this hammer!!”), please stop them (unless of course, you believe that the person deserves not having a device that could potentially be smarter than he/she is). Remember, these features are added onto devices for “what ifs” and “oops” situations. If you don’t have to put the devices to the test, be on the safe side and don’t, unless of course you have extra cash laying around to buy devices every time you decide to show your friends how you use your Motorola Defy for deep scuba diving.

Thanks for reading.

Sources, ratings and tables, and more information can be found in the following websites:

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