One of the nurses looking after my wife in hospital was notorious for crashing electronic equipment as soon as she touched it. Her colleagues thought it was a hoot but not her boss and he banned her from even going near his computer. I thought the tale was a bit far fetched till I watched her take a blood pressure reading. As soon as she put her hand on the machine it crashed.
My mind went back a number of years to an incident when I was a newly qualified computer technician just starting off in business. A firm I looked after had a typist/secretary who couldn't use a computer. Before they dispensed with her services they asked me to have a look at what she was doing to see if there was a simple solution to the problem because apart from this, she was a very good worker. I detached a computer from their network and set her off typing a letter. In less than 10 seconds the monitor went funny with the picture distorted and the computer froze. The lady dissolved in tears and fled to the toilet. I switched the computer off and rebooted it and all worked properly again so the problem was either static electricity or a stray magnetic field. I eliminated magnets as I could find no trace of a gauss field but where was the static coming from?
When the lady returned red eyed from the loo I was about to give up and confess myself beaten when I heard a sharp crack as she sat down.
"It's always doing that" she said as she shook her hand where a spark had jumped from her to the metal of the chair.
The penny dropped. The young lady was wearing a silky looking blouse and a pencil skirt. I asked her if she had a slip on and with great trepidation asked her what her undies were made of. She told me that both her slip and undies were silky man made material like her blouse.
Now those among you that have done physics at school will remember the demonstration of rubbing a glass rod with a silk handkerchief and then picking up scraps of paper using static electricity. What was happening was the young lady's undies were rubbing against her slip and blouse and having the same effect. Her plastic soled shoes were insulating her till she sat down in the metal chair and the electrical potential was high enough to generate a spark to jump the gap.
I asked the young lady to wear cotton clothing and undies the following day and we repeated the test. No sparks and the computer behaved itself. A neat and cost free solution.
Now back to our nurse. Her uniform is mostly made of polycotton and there is no way to change that so I had to do a bit of oblique thinking. Every computer technician will be used to using a wrist strap to earth themselves while handling electronic components so maybe this was the answer. I took a wrist strap with me on my next visit to the hospital and showed the nurse how to use it. Two days later when I took my wife for her regular treatment session the nurse wasn't on duty but all her colleagues were full of the story about how she could use a computer and the other electronics in the unit without something horrible happening.
The moral of this tale is that if ever you have to open the case of your computer, before you touch anything inside, put your hand on a radiator or metal sink for a few seconds and make sure you have drained away all the static electricity we all carry as part of our daily lives. Not everyone carries as much as the nurse or the fashion conscious secretary in the story but you may be carrying enough to seriously damage some of the parts inside your computer and you could land yourself with a big bill to put things right.
My mind went back a number of years to an incident when I was a newly qualified computer technician just starting off in business. A firm I looked after had a typist/secretary who couldn't use a computer. Before they dispensed with her services they asked me to have a look at what she was doing to see if there was a simple solution to the problem because apart from this, she was a very good worker. I detached a computer from their network and set her off typing a letter. In less than 10 seconds the monitor went funny with the picture distorted and the computer froze. The lady dissolved in tears and fled to the toilet. I switched the computer off and rebooted it and all worked properly again so the problem was either static electricity or a stray magnetic field. I eliminated magnets as I could find no trace of a gauss field but where was the static coming from?
When the lady returned red eyed from the loo I was about to give up and confess myself beaten when I heard a sharp crack as she sat down.
"It's always doing that" she said as she shook her hand where a spark had jumped from her to the metal of the chair.
The penny dropped. The young lady was wearing a silky looking blouse and a pencil skirt. I asked her if she had a slip on and with great trepidation asked her what her undies were made of. She told me that both her slip and undies were silky man made material like her blouse.
Now those among you that have done physics at school will remember the demonstration of rubbing a glass rod with a silk handkerchief and then picking up scraps of paper using static electricity. What was happening was the young lady's undies were rubbing against her slip and blouse and having the same effect. Her plastic soled shoes were insulating her till she sat down in the metal chair and the electrical potential was high enough to generate a spark to jump the gap.
I asked the young lady to wear cotton clothing and undies the following day and we repeated the test. No sparks and the computer behaved itself. A neat and cost free solution.
Now back to our nurse. Her uniform is mostly made of polycotton and there is no way to change that so I had to do a bit of oblique thinking. Every computer technician will be used to using a wrist strap to earth themselves while handling electronic components so maybe this was the answer. I took a wrist strap with me on my next visit to the hospital and showed the nurse how to use it. Two days later when I took my wife for her regular treatment session the nurse wasn't on duty but all her colleagues were full of the story about how she could use a computer and the other electronics in the unit without something horrible happening.The moral of this tale is that if ever you have to open the case of your computer, before you touch anything inside, put your hand on a radiator or metal sink for a few seconds and make sure you have drained away all the static electricity we all carry as part of our daily lives. Not everyone carries as much as the nurse or the fashion conscious secretary in the story but you may be carrying enough to seriously damage some of the parts inside your computer and you could land yourself with a big bill to put things right.
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