If one is actually interested in ('binary') continuity testing (rather than resistance measurement) - i.e. to determine 'what is connected to what by wires or other conductors (not components) (e.g. Harry's exercise) - whilst the buzzer/bell can be useful (if one has a lot to do), I suppose one would ideally have a means of adjusting the 'buzzer threshold' according to the circumstances of what one was dealing with - which would presumably be very easy to implement with anything 'electronic' (but not with a bell
).
I was out there staying in a motel, with no workshop facilities, little equipment and even less command of of the Italian language. I was asked if I would be willing to pick the job up on the Monday, spent an hour thinking about it, agreed and was on the plane on the Thursday. My passport had run out, when I agreed to go, so I spent Tuesday at the passport office with a letter from my employer expressing the urgency. The previous guy had arrived on site, taken one look at it and gone back home on the next flight. I was told it was one or two months, but I was still there 12 months later, when the job was finally abandoned for lack of funds.
I was told I would have the help of the Italian companies electrician as my assistant, that didn't happen - instead I had a willing 18 year relative of the owner as an assistant and another 14 year old relative, when he had finished school in the afternoon, helping. I had him/them buzzing the panels through, tracing it all out whilst I sat at a desk with the drawings, telling him the wire numbers to trace, from the relay/contactor number, in Italian and waiting for t\he buzz response. We got it down to a fine art, but it still took months.
The Italian company had basically been sold a massive pup, by Loewe, the German manufacturer of the process equipment. I was contracted to Davey/Loewe, the UK arm, to try to reassemble it all and get it working. The panels and the machinery had stood out in the open for years. The mechanicals were recoverable, but the control panels were obvious scrap, should have been scrapped and the Italians should have been told that, but Davey were making large sums of money out of the job, so they strung them along. I made my opinion known about the condition and was told to shut up. They had built a massive new building to house it all, a mezzanine floor for the high voltage incoming supplies, a long separate bay for all the control panels. I was just starting to study computers, processors in my spare time and thought what a wonderful opportunity to replace all of that relay logic with a CPU - a sort of predecessor to the modern PLC's, which I later became involved with.
It finally came to a stop, when the Italian government stepped in to stop the company spending out of the country and the company itself ran out of money - they went bankrupt soon after. Shame, it was a family business, employing lots of family and they were really nice people. A look on Googlearth, shows the entire place was later flattened and turned into an industrial estate, but the lunchtime trattoria just opposite is still there.