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richard.soderberg@mi*.ki*.se* notes:
>This message describes an on-land incident where an Aladin air-x computer
>malfunctioned.
>Prior to the incident the computer logged some 40 dives.
>The dive computer and a cellular phone (Ericsson GH337) were stored in
>the same bag and possibly in physical contact.
>The telephone rang and at the same time the computer started logging a
>dive at 2m. No combination of "contact touching" could reverse this.
>I contacted the Swedish vendor, CBM who promptly replaced the whole
>system without making any trouble. They pressure tested the air-x and it
>appeared to log a depth exactly 2m too deep.
>During this "computer dive" I noticed that an active cellular phone would
>influence the depth displayed at a distance of 50 cm (about 20 inches).
>The effect was a decereasing depth as the phone got closer.

Celphones contain a fairly sohisticated computer.  In addition,
they contain a number of oscillators that produce outputs at a
wide range of frequencies.  I don't think that either dive
computers nor celphones are engineered to operate side-by-side,
or within an inch of each other.

I'm not surprised to hear that they interfere with each other.

I _am_ surprised to hear that the interference from one produces
repeatable, measurable results on the other.

This should be a caution to test all your electronic devices
next to your life-support computers, in a non-diving situation.
That's celphones, dive computers, hoseless pressure gauges,
metal detectors, O2 sensors, and CD players (I used to date this
chick that threatened to kill me if I didn't have her favorite
Bauhaus CD to listen to -- so a CD player was DEFINITELY
a life-support device.)

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