17-11-2015, 02:43 PM
The best part of 50 years ago I had to demonstrate to a Factories Inspector that my workshop was an earth-free area with the earth leads of soldering irons, test equipment, etc. all lifted.
He went away satisfied but I wondered if he ever investigated the working environment of a field engineer who constantly walked through front doors in the course of a day, each one revealing its own unknown hazard zone ...
As one colleague discovered the hard way the wallpaper on an outside wall of an old house, after being subjected to a torrential downpour which had leached through the porous salt laden brickwork, could be surprisingly earthy right behind the TV he was working on ...
After I left the retail trade I worked on a cable network in the City. I wonder what a Factories Inspector would have made of a special receiver comprising a modified ITT-KB VC100 chassis with a three-core mains-lead, an earthed special multi-band VHF tuner and mains isolation on the IF connection between tuner and chassis.
Add to this that the top of a metal filing cabinet was a common place for one of these to be sited and you really had to have your wits about you ...!
He went away satisfied but I wondered if he ever investigated the working environment of a field engineer who constantly walked through front doors in the course of a day, each one revealing its own unknown hazard zone ...
As one colleague discovered the hard way the wallpaper on an outside wall of an old house, after being subjected to a torrential downpour which had leached through the porous salt laden brickwork, could be surprisingly earthy right behind the TV he was working on ...
After I left the retail trade I worked on a cable network in the City. I wonder what a Factories Inspector would have made of a special receiver comprising a modified ITT-KB VC100 chassis with a three-core mains-lead, an earthed special multi-band VHF tuner and mains isolation on the IF connection between tuner and chassis.
Add to this that the top of a metal filing cabinet was a common place for one of these to be sited and you really had to have your wits about you ...!
