When talking about rugged mobiles, design is left aside and the target is focused on performance. But not in those of the best camera or the most advanced microchip, but in the most demanding use to which a mobile can be subjected. It is true that many devices are waterproof and withstand extreme temperatures. But there is talk of fresh water and evaluating its resistance to cold temperatures on the one hand and hot temperatures on the other. However, the best rugged mobiles will face other much more severe tests.
The MIL-STD-810G military standards to which rugged mobiles are subjected, mention 12 tests . Some can be “approved” by conventional mobiles, others by devices that are supposed to be rugged, but few spend 12 hours with the same device. Something like the 12 labors of Hercules, but in a technological version.
To check to what extent mobile phones are forced, we have gone to the Crosscall testing laboratory, a firm that provides mobile phones to the French gendarmerie or the Madrid police, among others. There it is possible to see what the MIL-STD-810G standard is about. These tests were created by the US Army Test Laboratory for Equipment Development and seek to recreate extreme, hostile, and dangerous conditions that can occur in a real professional environment. And “real professional environment” is a very subjective thing: rescue personnel from Chamonix were able to use one of Crosscall’s devices, the Core-X5, at the South Pole in temperatures as low as -20°C .
Here the 12 tests, all passed by the same mobile (in this case a Core-X5) although obviously not at the same time.
1) TEMPERATURE SHOCK
Go from -40°C to 60°C in less than a minute (the change is repeated 3 consecutive times).
2) ANOTHER TEMPERATURE
More than 4 hours at a constant temperature of 60°C without showing any signs of surface deterioration. Its functional use (calls, sms…) is guaranteed at 71°C for 2 hours. For more time, you have to reduce the temperature.
3) LOW TEMPERATURE
Subject the device to a temperature of -51 °C for 4 hours, without showing any signs of deterioration of the surface. Its functional use (calls, sms…) is guaranteed at -40°C.
4) RAIN
Expose to adverse weather conditions for 30 minutes on each of its 6 faces, that is, 3 hours of adverse conditions (a flow of 10 cm/h, that is, drops of up to 4.5 mm in diameter with bursts of 65 km /h ).
Fresh water, salt water, thinner, gasoline or oil. Mobile phones are “bathed” in these liquids. PHOTO: BOBY
5) SALT FOG
A sodium chloride solution is sprayed onto the device. Spraying and drying are then alternated in cycles of 24 hours for 4 days at a temperature of 35°C.
6) POLLUTING FLUIDS
A solvent is sprayed for 24 hours.
7) VIBRATION
For 8 hours straight, the phone is subjected to prolonged exposure to strong shocks on each axis (X,Y,Z).
8) SHOCK TESTS
18 downloads are made, that is, 3 on each of the 6 faces on cement, wood, brick and marble.
9) ACCELERATION
Acceleration is carried out in all 6 directions, going from 0 to 72 km/h in 1 second.
10) RESISTANCE TO ALTITUDE (low pressure)
It lights up for one hour in a depressurized chamber at 57 kPa, which corresponds to using the phone at more than 4,000 meters.
11. SOLAR RADIATION (UV)
Expose to conditions that correspond to spending more than a week in areas of the world that are most exposed to UV rays (using xenon lamps to reproduce wavelengths of sunlight, from ultraviolet to infrared). This test is performed with a peak exposure of 1120W/m2 inducing a temperature with the potential to reach 49°C.
12) ICE/FROZEN RAIN
The device is exposed to 0 °C after spraying with water. The mobile is bathed in a stream of cold water for one hour at a temperature of around -10°C until a 13mm layer of ice forms on the phone. The ice is then kept there for another 4 hours. The phone should still work after unfreezing it.
To obtain the certificate of having passed these tests, it is necessary that they do not show any alteration in appearance, materials or functional characteristics after the test. To these we must add some extra tests that we have seen, such as submerging the mobile not only in fresh water, but also in sea water, oil and gasoline or applying a force of 200 kilos to see how much they bend.
