David Mery works in an office where the light is controlled by a single motion sensor that is relatively far from most of the desk-bound employees. When he wrote to the people managing his office to complain that one had to stand and flail about or lob a basketball at the sensor else work in the dark, particularly in the short days of winter (and sent this photo in to prove it), he received this illuminating explanation:
"The sensitivity of the sensors is set centrally for the whole building and is fine for most.
Oh well, David, there's always night vision goggles!
Here's a look at David's office with the lights on and the mal-positioned sensor:
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Comments (3)
Hi David,
I pity you as I was in the same type of office with exactly the same problem about 8 years ago, and this lasted for two or three years until a dreadful thing happened.
The firm was Thales in Crawley, and I designed electronic circuits.
We fixed up pieces of paper on the ceiling connected to a string to pull when the light went out, which was distracting when in the middle of a train of thought.
Writing to the maintainance department, they took no action, and desinging took much longer as a result.
I then found that a cooling fan positioned on a closer desk kept the light on.
Because of the noisy fan a collegue put thick carpet tiles round it (not my idea).
Unfortunately I forgot one day to switnh the fan off as it was on the other unused desk, when I went home. My colleauge did not either.
Late in the evening the security guy patrolling saw a fire starting from the desk; it was the fan, overheated due to the carpet tiles.
The place would have burnt down if he had not seen it.
Of course I got the blame and had to go to a diciplinary meeting with personnel, where I mentioned the other guy and his carpet tiles.
I was glad when it was time to retire after the way I was treated, and the dreadful dimly lit with no windows building.
Cheers,
Ray.
Posted by Ray Throssell | April 23, 2008 11:14 PM
@Karen, thanks for publishing this story.
@Ray, as these are motion and not heat sensors I haven't considered burning the place down :-) I have been tempted by a remote helicopter but have managed to resist temptation so far.
The ways these sensors are used is very much as if they are tools of a cult of technology for its own sake. They work great in places where people move and don't feel any affiliation to, such as staircases and corridors, but in city offices using a combination of one light switch per room and (education if needed and) trusting staff to use the switch has a much greater efficiency in term of productivity, morale and energy savings.
br -d
Posted by David Mery | April 24, 2008 10:33 PM
In a blog post here awhile back, I related this story from an expert witness who testifies in cases where automatic doors fail. It really underscores how lame David's maintenance department was in claiming they had a solution that was satisfactory for most everyone, and the diabolical challenge in adjusting sensor sensitivity: "Technicians had been called in almost on a monthly basis to make simple adjustments to the sensitivity of a door's control system. 'Somebody would complain that the door was "ghosting" or opening for pedestrians and vehicles simply passing by at a distance, so a technician would reduce the sensitivity or tilt the sensor downward,' he recalls. 'Then somebody else would complain that it wasn't opening every time a person wanted to pass through, and a different technician would come back and increase the sensitivity or tilt the sensor upward. The cycle would repeat all over again, until the adjustment was over-corrected and an individual was injured.' I assume they switched over to a manual door at that point!
Posted by Karen Field | April 24, 2008 10:46 PM