One of the more unusual requirements as presenter at Moodle Moot Au 2010 was to have my netbook tested for electrical safety. I was worried this would be a long and slow process, with my having to find an electrician in the basement of the conference centre. But there were three technicians from Jim’s Test & Tag Australia, each with test equipment, next to the conference registration desk.
The technician first examined the power supply, then attached two electrodes, pressed a button on the test unit, waited a few seconds and looked at a screen. They then pressed another button and a label was printed to be attached to the lead. As my power supply has a removable mains cable, this process had to be repeated for that cable and also for my 3G router, which has its own plug-pack. Even so the whole process only took a couple of minutes.
This all seems a little excessive, as laptops use double insulated external power supplies. These are designed to an international safety standard. Even if there was a failure in the unit, my laptop itself is encased in insulating plastic. About the worst which would happen is the computer would be destroyed by excessive voltage, without harming the operator. But better to be safe than sorry, and at international conferences there is an assortment of equipment brought along with electrical connections of uncertain origin. While I may feel safe from my laptop, I don't know about the one the person next to me brought along.