As promised, here are the FCC and
CE testing pictures:
Knut in a test chamber about to
be hit with 3 volts per centimeter in air. The test chamber is shielded room
covered in thousands of ferrite tiles. When the door to the test chamber is
closed, almost all radio waves are blocked from reaching the outside world.
(Sorry about the bad picture quality):
A prescan being
done on Knut to see what radio frequencies is being emitted by Knut when no
external interference is applied. The high peak on the left is 2.4 GHz (the
frequency of Wi-Fi)
shown here are the result of a 4 separate scans called presweeps. Presweeps
give the testing house an idea of how your device will perform for the rest of
the tests. Not unlike pressing the scan button on your car radio, the equipment
scans through a very large set of frequencies to see on what frequencies Knut
is producing a signal. The straight line in the middle of each graph is the
limit and if Knut exceeds a limit, Knut will likely fail subsequent tests. Knut
does exceed 1 limit at 2.4GHz but is allowed to because Knut is designed to
transmit at 2.4GHz.
This data is
not official FCC and CE testing data and I don't have access to the official
data until all tests are completely done. This picture is actually full
resolution. You need to save this picture to your computer to see it in full
Here is Knut
being viewed by a camera inside the test chamber. No one can be in the test
chamber during the test because intense radio waves are generated which are bad
for human health. A test would take a few minutes and then they would re-enter
the chamber and rotate Knut a different angle, and then run another test. Then
after a few more tests they would enter the chamber and rotate an enormous
Knut being shocked
with 4000 volts:
This actually went a lot better
than I thought it would. Knut messed up a little bit but recovered on its own
so it's still considered a pass. Knut had a moment of time traveling when it
suddenly reported that it was 2:16:36 PM when it was actually 1:57:43 PM. The
battery also indicated that it was empty but then recovered.
Internal Temp 1:56:44 PM 2/1/2013
Battery 1:56:59 PM 2/1/2013 99.39%
Internal Temp 2:16:36 PM 2/1/2013
Battery 1:57:43 PM 2/1/2013 0.32%
Internal Temp 1:57:44 PM 2/1/2013 73.4F
Battery 1:57:58 PM 2/1/2013 99.39%
Knut had to be field tested to
determine how it would act in the real world. It's difficult to test in the
real world in the middle of a snow storm. F2 Labs has an awesome inflatable
bubble to deal with this. Its kept inflated with 2 huge air pumps and its
always under positive pressure. The entrance to the bubble is 2 doors with an
air lock in between. If you open both doors, the whole bubble deflates and
breaks all sorts of expensive equipment inside. My ears popped a little when I
entered, but the people at F2 said that they don't notice that.
A view of inside the bubble. This
bubble is huge. You could easily play soccer in here. In fact a some grass is
growing on the left. On the left, closest to the camera is Knut on a
table.The table can rotate 360 degrees.
In the middle, very far away is a gigantic antenna. The antenna can slide up and
down. During the test they rotate Knut around and raise the antenna up and down
to see what radio waves Knut generates.
in another test chamber:
I had a lot more photos but somehow they disappeared... It's
very strange. I took many of various antennas and many additional shots of the first
chamber. They might have gone missing during the test that they applied 4000
volts to Knut because that was really the only time that my iPhone was exposed
to any strange interference.
Oh and also, Knut passed FCC today. CE has some additional tests that need to be done like drop tests, high and low humidity tests, high and low temperature tests and other tests that take weeks.