So we’ve been talking about drop testing, but just how is equipment tested and certified? Well the first important piece of information is that it isn’t!….well at least there’s no special test centre that does it and gives you a pass grade and certificate anyway. Instead the testing and statements made on spec sheets are down to the manufacturers.
Drop test uncovered
The drop spec is basically a series of drops onto each face of the device. You need to drop the device 26 times STD 810 Transit drop is the one we tend to see in the rugged computer world. Interestingly the floor of the drop zone can be made up of two inches of plywood over concrete and whilst determined as the most common surface a device was likely to land on I think pure concrete is best for enterprise. I have asked various manufacturers about what they test on and none of them have come back to me with a definitive answer to the question. Devices only have to be dropped from 4 feet but of course we see many dropped from higher. and the test consists of 26 drops on:
- Each of its six faces
- It’s 12 edges
- It’s eight corners
So the test totals 26 drops. Damage is determined after each drop and the drops can be divided up among 5 identical PDA’s, so the test isn’t particularly hard to pass and with 5 devices on hand to pass it with, drops to wood and often with a lack of transparency in the testing processes it’s confusing at best.
Tumble & Vibration
Tumble tests are designed to simulate a different kind of impact and these can be done from different heights by using different sized chambers. The device is placed into the chamber and then spun slowly so that it drops and “tumbles” as it is spun over and over. The tests can be for 1000 or 2000 tumbles and the device is checked after the full tumble set. Vibration sees a device subjected to various frequencies of vibration over a set time to see if anything can work lose.
A little video!
To give you a little more, the best video I’ve seen of a lot of rugged tests you can do is this one from Getac. Note the wood covered concrete!! http://www.youtube.com/watch?v=WfDqtLj7CHg
You know, I sometimes wonder if everyone lies these days. Mileage tests on cars are lies, if it weren’t for whatcar magazine we’d never really know. Why would spec sheets on rugged devices be any different? So we test and test and test here, on our own, in the field and with customers too so we have lots of real and practical experience to share. What we’ve found is a lot of kit that looks a bit cheap at first actually performs better than their spec sheets. For example we’ve been testing a Chinese device recently that has been under 1M of water for weeks, dropped from 2M’s 50+ times according to MIL testing and it’s still alive and kicking, not even a screen crack. We also test branded equipment that in no way lives up to it’s spec sheet testing. We see devices where battery covers ping off on every drop, IP42 that’s meaningless and all kinds of MIL tests that can’t live up to their claims. Mould resistances on devices with micro-usb connectors is a particular favourite of mine right now!!
What i’d leave you with is that everything has caught up these days and it’s very hard to buy a poor piece of hardware on it’s own. So ask about a device, don’t rely on spec sheets, use resellers unbiased experience to work out what’s best for you.