So the hunt for Rugged PDA Ruggedness goes on! In my last post we looked at IP ratings, in this post we try to undercover the truth behind drop specs as well as explaining what all these funny little MIL-STD standards all mean.
The drop test
Some drop tests are more equal than others!
Many thanks to M3 Mobile and iPhyone4um for the vid sharing!
The Drop Specification Process
In a nutshell you’re looking for a drop spec on the spec sheet and these tend to range from 1.2 to 1.8m. The official rating is performed in the first test you see in the video above but there are various other tests outlined below.
What does the height mean?
Firstly it doesn’t necessarily mean that the rugged pda is “guaranteed” to work after being dropped from the given height, I think it is more of a relative measure of the shock protection being offered, especially where there is no MIL-STD standard present (We’ll come on to that in a moment). It’s best used as a relative form of comparison rather than on its own but there are a few things you should know when comparing! Firstly beware anything less than 1.5m as this height is a bit meaningless. My opinion is that 1.5m is the minimum needed for a rugged device and 1.2m is not really telling you much at all in my view as you would expect your mobile phone to work if dropped form your hip wouldn’t you?
What’s it dropped on to?
Not all drop tests are equal! Whilst most manufacturers drop onto concrete and usually state that, you will find all sorts of flooring used for tests. Now there is a debate about this because often you will find that the device is dropped on to the flooring that it is most likely be used on. Socket for example drop onto “vinyl covered concrete” and low and behold you see their rugged PDA’s all over hospitals! Some drop on to “Steel”. Is this a better or worse test than onto concrete? The answer is that we don’t truly know because whilst concrete is obviously harder, steel will incur a bounce and thus more hits on the device.
How many times is it dropped?
Again this is important in terms of knowing how extensive the manufacturer tests have been, however it doesn’t necessarily mean that a device tested 26 times to MIL-STDF-503.4 will not break on drop 21 or will definitely break on drop 27! I think its important to see the committment shown by the tests but its more important not to get too hung up on these tests and to focus on how relevant they really are to your working environment.
The tumble test
This is a variant of the drop test and is where the rugged pda is “Tumbled” from a lower height, usually about 1.5 to 2 feet but more times. It is supposed to mirror every day dropping of devices from pockets, desk or cradles where you would not expect the instant shock to damage the device but the long term dropping to be a factor.
Again there’s not much I can add here and everyone does this differently so its hard to judge. Use this as a relative comparison to your search for a rugged PDA!
What is a MIL standard and is it useful or not?
So The MIL standard is actually an attempt to create some standard testing certification to the Rugged PDA world. However despite the test not being really devised for the Rugged PDA, it does have some good stuff in it. It also doesn’t just cover drop or shock testing but a whole plethora of tests including salt, rain, shock, temperature, fungus, fog, pressure and the list goes on.
What do I think about MIL-STD Tests? Well to be truthful at first glance you see some manufacturers adopting it fully and making their devices look great on paper. This is especially useful for the top end rugged devices that are selling on the “Rugged” USP. I would say Geta, Trimble and those types of manufacturers are where this stuff is really relevant and useful. However for the rest, you need to scratch the surface of this because there are so many tests with the MIL-STD that you often see irregularities in the spec sheets and they still don’t mean that a device is more rugged than one without any MIL-STD testing.
Because it’s not an industry-wide adopted certification some adopt it and some don’t and I would have to say you tend to see the established Western brands throwing money… I mean adopting them whilst the Eastern and emerging brands focus on innovation of their devices.
I think it’s commendable to see a MIL standard in the spec sheet but in my experience it doesn’t mean anything until everyone is made to use them, and a great example of that is the MM3 in the Video above. It doesn’t have a MIL-STD but you won’t find a video anywhere from Motorola or Intermec drop testing their devices from that height! Let me know if you rise to the challenge!!
So I hope to have uncovered the areas to look for in a drop test and although this sounds like a plug, I will leave you with the advice that you need to talk to a decent rugged Reseller who can help you through this because, as I hope to have demonstrated here, there’s a lot more than just the spec sheet tells you!
Next we’re looking at how the overall design of a Rugged PDA can make all the difference.
The Rugged and Mobile blog.