|
Zanzibar effect
who has got caught out by the Zanzibar effect when calibrating
things..me for one |
Zanzibar effect
On 22/08/2020 07:27, Jim GM4DHJ ... wrote:
Zanzibar effect I bet more people get caught out by assuming that last digit in a digital display means that the measuring equipment is accurate to that resolution or not understanding that (+/-1%. +2) may mean an inaccuracy in measurement of 10%, or more, in what they are trying to measure. This is assuming that the £5 multimeter from China was even checked for correct reading in the first place. -- mailto : news {at} admac {dot} myzen {dot} co {dot} uk |
Zanzibar effect
On 22/08/2020 10:40, alan_m wrote:
On 22/08/2020 07:27, Jim GM4DHJ ... wrote: Zanzibar effect I bet more people get caught out by assuming that last digit in a digital display means that the measuring equipment is accurate to that resolution or not understanding that (+/-1%. +2) may mean an inaccuracy in measurement of 10%, or more, in what they are trying to measure. This is assuming that the £5 multimeter from China was even checked for correct reading in the first place. very true I never have the last digit on on my ham rigso on for that reason and the fact that I calibrated them myself...tee hee....near enough is good enough for me..... |
Zanzibar effect
On 22/08/2020 10:54, Tim Streater wrote:
On 22 Aug 2020 at 10:40:05 BST, alan_m wrote: On 22/08/2020 07:27, Jim GM4DHJ ... wrote: Zanzibar effect I bet more people get caught out by assuming that last digit in a digital display means that the measuring equipment is accurate to that resolution or not understanding that (+/-1%. +2) may mean an inaccuracy in measurement of 10%, or more, in what they are trying to measure. This is assuming that the £5 multimeter from China was even checked for correct reading in the first place. That's prolly because most people have never come across the concept of errors in measuring equipment. I will be honest up to until one of my multimeters told me my PSU was giving 14.1 volts and another said 13.8 volts I never questioned any multimeters.....but now I am on Zanzibar time as I adjusted them all to match the one I thought was accurate...tee hee...near enough is good enough for me.... |
Zanzibar effect
In article ,
alan_m wrote: On 22/08/2020 07:27, Jim GM4DHJ ... wrote: Zanzibar effect I bet more people get caught out by assuming that last digit in a digital display means that the measuring equipment is accurate to that resolution or not understanding that (+/-1%. +2) may mean an inaccuracy in measurement of 10%, or more, in what they are trying to measure. This is assuming that the 5 multimeter from China was even checked for correct reading in the first place. I can remember the BBC sending back a large delivery of Avo 8s which were all out of spec ;-( -- from KT24 in Surrey, England "I'd rather die of exhaustion than die of boredom" Thomas Carlyle |
Zanzibar effect
On 22/08/2020 12:38, Jim GM4DHJ ... wrote:
I will be honest up to until one of my multimeters told me my PSU was giving 14.1 volts and another said 13.8 volts I never questioned any multimeters.....but now I am on Zanzibar time as I adjusted them all to match the one I thought was accurate...tee hee...near enough is good enough for me.... Multimeters also give inaccurate results if the internal batteries are close to end of life. -- mailto : news {at} admac {dot} myzen {dot} co {dot} uk |
Zanzibar effect
On 22/08/2020 12:35, Jim GM4DHJ ... wrote:
very true I never have the last digit on on my ham rigso on for that reason and the fact that I calibrated them myself...tee hee....near enough is good enough for me..... You have NOT calibrated them yourself unless you have a calibrated source as a comparison. -- mailto : news {at} admac {dot} myzen {dot} co {dot} uk |
Zanzibar effect
On 22/08/2020 12:45, charles wrote:
In article , alan_m wrote: On 22/08/2020 07:27, Jim GM4DHJ ... wrote: Zanzibar effect I bet more people get caught out by assuming that last digit in a digital display means that the measuring equipment is accurate to that resolution or not understanding that (+/-1%. +2) may mean an inaccuracy in measurement of 10%, or more, in what they are trying to measure. This is assuming that the £5 multimeter from China was even checked for correct reading in the first place. I can remember the BBC sending back a large delivery of Avo 8s which were all out of spec ;-( 40+ years ago I worked in a calibration lab and can remember every single expensive Philips multimeter being out of spec, even when straight from their factory. -- mailto : news {at} admac {dot} myzen {dot} co {dot} uk |
Zanzibar effect
On 22/08/2020 12:49, alan_m wrote:
On 22/08/2020 12:35, Jim GM4DHJ ... wrote: very true I never have the last digit on on my ham rigso on for that reason and the fact that I calibrated them myself...tee hee....near enough is good enough for me..... You have NOT calibrated them yourself unless you have a calibrated source as a comparison. I know that but near enough is good enough |
Zanzibar effect
On 22/08/2020 12:45, charles wrote:
In article , alan_m wrote: On 22/08/2020 07:27, Jim GM4DHJ ... wrote: Zanzibar effect I bet more people get caught out by assuming that last digit in a digital display means that the measuring equipment is accurate to that resolution or not understanding that (+/-1%. +2) may mean an inaccuracy in measurement of 10%, or more, in what they are trying to measure. This is assuming that the £5 multimeter from China was even checked for correct reading in the first place. I can remember the BBC sending back a large delivery of Avo 8s which were all out of spec ;-( I got a NATO issue one up ra barras in Glasgow |
Zanzibar effect
In article , Tim Streater
wrote: On 22 Aug 2020 at 12:46:46 BST, alan_m wrote: On 22/08/2020 12:38, Jim GM4DHJ ... wrote: I will be honest up to until one of my multimeters told me my PSU was giving 14.1 volts and another said 13.8 volts I never questioned any multimeters.....but now I am on Zanzibar time as I adjusted them all to match the one I thought was accurate...tee hee...near enough is good enough for me.... Multimeters also give inaccurate results if the internal batteries are close to end of life. I remember from school there being a certain type of battery that had a very precise voltage and well defined, so it was used to calibrate against. Can't remember what it was called, though. Anyone? Reference cell -- from KT24 in Surrey, England "I'd rather die of exhaustion than die of boredom" Thomas Carlyle |
Zanzibar effect
"alan_m" wrote in message
... 40+ years ago I worked in a calibration lab and can remember every single expensive Philips multimeter being out of spec, even when straight from their factory. Were they all out spec by the same amount, or was there a spread of readings for the same test source? Digital meters which quote an unfeasible number of digits of precision are probably only useful (in the last digit or so) for comparing two different voltages in quick succession to see how one differs from the other, and measured near-simultaneously so thermal drift is less likely to be an issue. My Uni-T multimeter quotes voltages in the 0-2V range to 3 decimal places. I might trust it to show a difference of 10 mV between two signals, without necessarily knowing whether a reading of 1.318 V was correct compared with a known-good reference cell. I might trust that a change in the final 3rd digit was valid if I got a consistent reading over several seconds that then changed by +/- 1 mV and remained consistent over several seconds when something happened. For example, comparing a battery voltage with and without a load applied. But I wouldn't go so far as to say that the change was 1 mV as opposed to "a few mV". |
Zanzibar effect
"Jim GM4DHJ ..." wrote in message
... who has got caught out by the Zanzibar effect when calibrating things..me for one What is the Zanzibar effect? I can't find anything on Google so it's evidently not a widely-known term. |
Zanzibar effect
On 22/08/2020 14:58, NY wrote:
"Jim GM4DHJ ..." wrote in message ... who has got caught out by the Zanzibar effect when calibrating things..me for one What is the Zanzibar effect? I can't find anything on Google so it's evidently not a widely-known term. Zanzibar effect The famous story of the retired sea-captain on the island who takes his time from the watchmaker in town only to find out that the watchmaker uses the sea-captains cannon shots at 12 noon each day to set his own clocks! [Attributed to Harrison (MIT) by Petley.] -- mailto : news {at} admac {dot} myzen {dot} co {dot} uk |
Zanzibar effect
"Chris Hogg" wrote in message
... On Sat, 22 Aug 2020 14:58:08 +0100, "NY" wrote: "Jim GM4DHJ ..." wrote in message ... who has got caught out by the Zanzibar effect when calibrating things..me for one What is the Zanzibar effect? I can't find anything on Google so it's evidently not a widely-known term. Zanzibar time : https://tinyurl.com/suqbk29 Basically, a circular calibration process. A calibrates his instrument against an instrument owned by B, who unbeknown to A, calibrates his instrument against A's. Interesting that googling for the phrase as quoted "zanzibar effect" does not produce any matches. Lots of matches for the country of that name, but nothing else. Even googling for "zanzibar time" or "zanzibar effect time" doesn't produce any matches. I can understand the problem of circular calibration, but I'd never have been able to discover or even guess what it was from the phrase, assuming I hadn't already heard of it. |
Zanzibar effect
On 22/08/2020 17:45, NY wrote:
"Chris Hogg" wrote in message ... On Sat, 22 Aug 2020 14:58:08 +0100, "NY" wrote: "Jim GM4DHJ ..." wrote in message ... who has got caught out by the Zanzibar effect when calibrating things..me for one What is the Zanzibar effect? I can't find anything on Google so it's evidently not a widely-known term. Zanzibar time : https://tinyurl.com/suqbk29 Basically, a circular calibration process. A calibrates his instrument against an instrument owned by B, who unbeknown to A, calibrates his instrument against A's. Interesting that googling for the phrase as quoted "zanzibar effect" does not produce any matches. Lots of matches for the country of that name, but nothing else. Even googling for "zanzibar time" or "zanzibar effect time" doesn't produce any matches. I can understand the problem of circular calibration, but I'd never have been able to discover or even guess what it was from the phrase, assuming I hadn't already heard of it. https://metrology.wordpress.com/stat...-traceability/ |
Zanzibar effect
On 22/08/2020 18:05, Jim GM4 DHJ ... wrote:
On 22/08/2020 17:45, NY wrote: "Chris Hogg" wrote in message ... On Sat, 22 Aug 2020 14:58:08 +0100, "NY" wrote: "Jim GM4DHJ ..." wrote in message ... who has got caught out by the Zanzibar effect when calibrating things..me for one What is the Zanzibar effect? I can't find anything on Google so it's evidently not a widely-known term. Zanzibar time : https://tinyurl.com/suqbk29 Basically, a circular calibration process. A calibrates his instrument against an instrument owned by B, who unbeknown to A, calibrates his instrument against A's. Interesting that googling for the phrase as quoted "zanzibar effect" does not produce any matches. Lots of matches for the country of that name, but nothing else. Even googling for "zanzibar time" or "zanzibar effect time" doesn't produce any matches. I can understand the problem of circular calibration, but I'd never have been able to discover or even guess what it was from the phrase, assuming I hadn't already heard of it. https://metrology.wordpress.com/stat...-traceability/ more to it than that but can't find the better story at the moment.... |
Zanzibar effect
On 22/08/2020 17:45, NY wrote:
"Chris Hogg" wrote in message ... On Sat, 22 Aug 2020 14:58:08 +0100, "NY" wrote: What is the Zanzibar effect? I can't find anything on Google so it's evidently not a widely-known term. Zanzibar time : https://tinyurl.com/suqbk29 Basically, a circular calibration process. A calibrates his instrument against an instrument owned by B, who unbeknown to A, calibrates his instrument against A's. Interesting that googling for the phrase as quoted "zanzibar effect" does not produce any matches. Lots of matches for the country of that name, but nothing else. Even googling for "zanzibar time" or "zanzibar effect time" doesn't produce any matches. I can understand the problem of circular calibration, but I'd never have been able to discover or even guess what it was from the phrase, assuming I hadn't already heard of it. "Zanzibar effect" (with the quotes) gives (me) this as the first result: https://metrology.wordpress.com/stat...-traceability/ "The famous story of the retired sea-captain on the island who takes his time from the watchmaker in town only to find out that the watchmaker uses the sea-captains cannon shots at 12 noon each day to set his own clocks! [Attributed to Harrison (MIT) by Petley.]" Without the quotes it's a bit further down the list. But I agree it's not easy to find. -- Max Demian |
Zanzibar effect
"Jim GM4 DHJ ..." wrote in message
... On 22/08/2020 17:45, NY wrote: "Chris Hogg" wrote in message ... On Sat, 22 Aug 2020 14:58:08 +0100, "NY" wrote: "Jim GM4DHJ ..." wrote in message ... who has got caught out by the Zanzibar effect when calibrating things..me for one What is the Zanzibar effect? I can't find anything on Google so it's evidently not a widely-known term. Zanzibar time : https://tinyurl.com/suqbk29 Basically, a circular calibration process. A calibrates his instrument against an instrument owned by B, who unbeknown to A, calibrates his instrument against A's. Interesting that googling for the phrase as quoted "zanzibar effect" does not produce any matches. Lots of matches for the country of that name, but nothing else. Even googling for "zanzibar time" or "zanzibar effect time" doesn't produce any matches. I can understand the problem of circular calibration, but I'd never have been able to discover or even guess what it was from the phrase, assuming I hadn't already heard of it. https://metrology.wordpress.com/stat...-traceability/ Yes, there are references out there. It's strange that none of them (as far as I can find) seem to be findable by Google. Was there anyone else who's read this thread who had never heard of it and yet was able to find out what it meant? Am I just crap at being able to "drive" Google? |
Zanzibar effect
"Chris Hogg" wrote in message
... I can understand the problem of circular calibration, but I'd never have been able to discover or even guess what it was from the phrase, assuming I hadn't already heard of it. I've been familiar with the phrase for many decades. At some time in the past I wanted to be able to link to it on occasions such as this, so did a Google search but don't now remember the search terms. I saved the link in my 'favourites' list. Despite doing physics to A level and then elec eng at university, I've never heard of it before today, either by name or as a story, though I've heard many times of circular calibration. The sea captain and watchmaker could also be an example of a systematic error getting gradually worse. If the watchmaker is accurate and the sea captain takes a couple of seconds to adjust his clock in sync, that error (plus a similar error on the watchmaker's part when he syncs to the captain's time) will affect the watchmaker's new time - and so on repeatedly. |
Zanzibar effect
On 22/08/2020 18:45, NY wrote:
"Jim GM4 DHJ ..." wrote in message ... On 22/08/2020 17:45, NY wrote: "Chris Hogg" wrote in message ... On Sat, 22 Aug 2020 14:58:08 +0100, "NY" wrote: "Jim GM4DHJ ..." wrote in message ... who has got caught out by the Zanzibar effect when calibrating things..me for one What is the Zanzibar effect? I can't find anything on Google so it's evidently not a widely-known term. Zanzibar time : https://tinyurl.com/suqbk29 Basically, a circular calibration process. A calibrates his instrument against an instrument owned by B, who unbeknown to A, calibrates his instrument against A's. Interesting that googling for the phrase as quoted "zanzibar effect" does not produce any matches. Lots of matches for the country of that name, but nothing else. Even googling for "zanzibar time" or "zanzibar effect time" doesn't produce any matches. I can understand the problem of circular calibration, but I'd never have been able to discover or even guess what it was from the phrase, assuming I hadn't already heard of it. https://metrology.wordpress.com/stat...-traceability/ Yes, there are references out there. It's strange that none of them (as far as I can find) seem to be findable by Google. Was there anyone else who's read this thread who had never heard of it and yet was able to find out what it meant? Am I just crap at being able to "drive" Google? don't ask me... |
Zanzibar effect
On 22/08/2020 18:34, Max Demian wrote:
On 22/08/2020 17:45, NY wrote: "Chris Hogg" wrote in message ... On Sat, 22 Aug 2020 14:58:08 +0100, "NY" wrote: What is the Zanzibar effect? I can't find anything on Google so it's evidently not a widely-known term. Zanzibar time : https://tinyurl.com/suqbk29 Basically, a circular calibration process. A calibrates his instrument against an instrument owned by B, who unbeknown to A, calibrates his instrument against A's. Interesting that googling for the phrase as quoted "zanzibar effect" does not produce any matches. Lots of matches for the country of that name, but nothing else. Even googling for "zanzibar time" or "zanzibar effect time" doesn't produce any matches. I can understand the problem of circular calibration, but I'd never have been able to discover or even guess what it was from the phrase, assuming I hadn't already heard of it. "Zanzibar effect" (with the quotes) gives (me) this as the first result: https://metrology.wordpress.com/stat...-traceability/ "The famous story of the retired sea-captain on the island who takes his time from the watchmaker in town only to find out that the watchmaker uses the sea-captains cannon shots at 12 noon each day to set his own clocks! [Attributed to Harrison (MIT) by Petley.]" Without the quotes it's a bit further down the list. But I agree it's not easy to find. that is not the full story ... |
Zanzibar effect
On 22/08/2020 20:04, NY wrote:
"Chris Hogg" wrote in message ... I can understand the problem of circular calibration, but I'd never have been able to discover or even guess what it was from the phrase, assuming I hadn't already heard of it. I've been familiar with the phrase for many decades. At some time in the past I wanted to be able to link to it on occasions such as this, so did a Google search but don't now remember the search terms. I saved the link in my 'favourites' list. Despite doing physics to A level and then elec eng at university, I've never heard of it before today, either by name or as a story, though I've heard many times of circular calibration. The sea captain and watchmaker could also be an example of a systematic error getting gradually worse. If the watchmaker is accurate and the sea captain takes a couple of seconds to adjust his clock in sync, that error (plus a similar error on the watchmaker's part when he syncs to the captain's time) will affect the watchmaker's new time - and so on repeatedly. somebody else was involved as well...a third party |
Zanzibar effect
On 22/08/2020 18:34, Max Demian wrote:
On 22/08/2020 17:45, NY wrote: "Chris Hogg" wrote in message ... On Sat, 22 Aug 2020 14:58:08 +0100, "NY" wrote: What is the Zanzibar effect? I can't find anything on Google so it's evidently not a widely-known term. Zanzibar time : https://tinyurl.com/suqbk29 Basically, a circular calibration process. A calibrates his instrument against an instrument owned by B, who unbeknown to A, calibrates his instrument against A's. Interesting that googling for the phrase as quoted "zanzibar effect" does not produce any matches. Lots of matches for the country of that name, but nothing else. Even googling for "zanzibar time" or "zanzibar effect time" doesn't produce any matches. I can understand the problem of circular calibration, but I'd never have been able to discover or even guess what it was from the phrase, assuming I hadn't already heard of it. "Zanzibar effect" (with the quotes) gives (me) this as the first result: https://metrology.wordpress.com/stat...-traceability/ "The famous story of the retired sea-captain on the island who takes his time from the watchmaker in town only to find out that the watchmaker uses the sea-captains cannon shots at 12 noon each day to set his own clocks! [Attributed to Harrison (MIT) by Petley.]" Without the quotes it's a bit further down the list. But I agree it's not easy to find. that is not even the watchmaker involved ...that shop is on some Spanish island .... |
Zanzibar effect
On 22/08/2020 20:46, Jim GM4 DHJ ... wrote:
On 22/08/2020 20:04, NY wrote: "Chris Hogg" wrote in message ... I can understand the problem of circular calibration, but I'd never have been able to discover or even guess what it was from the phrase, assuming I hadn't already heard of it. I've been familiar with the phrase for many decades. At some time in the past I wanted to be able to link to it on occasions such as this, so did a Google search but don't now remember the search terms. I saved the link in my 'favourites' list. Despite doing physics to A level and then elec eng at university, I've never heard of it before today, either by name or as a story, though I've heard many times of circular calibration. The sea captain and watchmaker could also be an example of a systematic error getting gradually worse. If the watchmaker is accurate and the sea captain takes a couple of seconds to adjust his clock in sync, that error (plus a similar error on the watchmaker's part when he syncs to the captain's time) will affect the watchmaker's new time - and so on repeatedly. somebody else was involved as well...a third party some sort of weather station I think ....who spilled the beans |
Zanzibar effect
On Sat, 22 Aug 2020 17:45:15 +0100, NY wrote:
I can understand the problem of circular calibration, but I'd never have been able to discover or even guess what it was from the phrase, assuming I hadn't already heard of it. Nor me. At first, I assumed it was to do with overpopulation (some may recognose the reference). -- My posts are my copyright and if @diy_forums or Home Owners' Hub wish to copy them they can pay me £1 a message. Use the BIG mirror service in the UK: http://www.mirrorservice.org *lightning surge protection* - a w_tom conductor |
Zanzibar effect
On Sat, 22 Aug 2020 18:34:24 +0100, Max Demian wrote:
"Zanzibar effect" (with the quotes) gives (me) this as the first result: https://metrology.wordpress.com/stat.../basic-theory- of-measurement-and-error/trueness-%E2%80%93-calibration-and-traceability/ "The famous story of the retired sea-captain on the island who takes his time from the watchmaker in town only to find out that the watchmaker uses the sea-captains cannon shots at 12 noon each day to set his own clocks! [Attributed to Harrison (MIT) by Petley.]" Rather nice that the story involves someone called Harrison. -- My posts are my copyright and if @diy_forums or Home Owners' Hub wish to copy them they can pay me £1 a message. Use the BIG mirror service in the UK: http://www.mirrorservice.org *lightning surge protection* - a w_tom conductor |
Zanzibar effect
On 22/08/2020 22:00, Chris Hogg wrote:
On Sat, 22 Aug 2020 20:53:08 +0100, "Jim GM4 DHJ ..." wrote: On 22/08/2020 20:46, Jim GM4 DHJ ... wrote: On 22/08/2020 20:04, NY wrote: "Chris Hogg" wrote in message ... I can understand the problem of circular calibration, but I'd never have been able to discover or even guess what it was from the phrase, assuming I hadn't already heard of it. I've been familiar with the phrase for many decades. At some time in the past I wanted to be able to link to it on occasions such as this, so did a Google search but don't now remember the search terms. I saved the link in my 'favourites' list. Despite doing physics to A level and then elec eng at university, I've never heard of it before today, either by name or as a story, though I've heard many times of circular calibration. The sea captain and watchmaker could also be an example of a systematic error getting gradually worse. If the watchmaker is accurate and the sea captain takes a couple of seconds to adjust his clock in sync, that error (plus a similar error on the watchmaker's part when he syncs to the captain's time) will affect the watchmaker's new time - and so on repeatedly. somebody else was involved as well...a third party some sort of weather station I think ....who spilled the beans Are you thinking of this version https://tinyurl.com/y6459kdn (Reference 11, bottom of second column)? There are probably several variants of the story. That's the baby...thanks...... |
Zanzibar effect
On 23/08/2020 05:57, Jim GM4DHJ ... wrote:
On 22/08/2020 22:00, Chris Hogg wrote: On Sat, 22 Aug 2020 20:53:08 +0100, "Jim GM4 DHJ ..." wrote: On 22/08/2020 20:46, Jim GM4 DHJ ... wrote: On 22/08/2020 20:04, NY wrote: "Chris Hogg" wrote in message ... I can understand the problem of circular calibration, but I'd never have been able to discover or even guess what it was from the phrase, assuming I hadn't already heard of it. I've been familiar with the phrase for many decades. At some time in the past I wanted to be able to link to it on occasions such as this, so did a Google search but don't now remember the search terms. I saved the link in my 'favourites' list. Despite doing physics to A level and then elec eng at university, I've never heard of it before today, either by name or as a story, though I've heard many times of circular calibration. The sea captain and watchmaker could also be an example of a systematic error getting gradually worse. If the watchmaker is accurate and the sea captain takes a couple of seconds to adjust his clock in sync, that error (plus a similar error on the watchmaker's part when he syncs to the captain's time) will affect the watchmaker's new time - and so on repeatedly. somebody else was involved as well...a third party some sort of weather station I think ....who spilled the beans Are you thinking of this version https://tinyurl.com/y6459kdn (Reference 11, bottom of second column)? There are probably several variants of the story. That's the baby...thanks...... Think that is the true version....well the true made up version |
Zanzibar effect
On 22/08/2020 12:49, alan_m wrote:
On 22/08/2020 12:35, Jim GM4DHJ ... wrote: very true I never have the last digit on on my ham rigso on for that reason and the fact that I calibrated them myself...tee hee....near enough is good enough for me..... You have NOT calibrated them yourself unless you have a calibrated source as a comparison. just used radio 4 on 198 Kc/s Icom rigs drift off frequency because they use cheap variable resistors.... |
Zanzibar effect
On 22/08/2020 20:48, Jim GM4 DHJ ... wrote:
On 22/08/2020 18:34, Max Demian wrote: On 22/08/2020 17:45, NY wrote: "Chris Hogg" wrote in message ... On Sat, 22 Aug 2020 14:58:08 +0100, "NY" wrote: What is the Zanzibar effect? I can't find anything on Google so it's evidently not a widely-known term. Zanzibar time : https://tinyurl.com/suqbk29 Basically, a circular calibration process. A calibrates his instrument against an instrument owned by B, who unbeknown to A, calibrates his instrument against A's. Interesting that googling for the phrase as quoted "zanzibar effect" does not produce any matches. Lots of matches for the country of that name, but nothing else. Even googling for "zanzibar time" or "zanzibar effect time" doesn't produce any matches. I can understand the problem of circular calibration, but I'd never have been able to discover or even guess what it was from the phrase, assuming I hadn't already heard of it. "Zanzibar effect" (with the quotes) gives (me) this as the first result: https://metrology.wordpress.com/stat...-traceability/ "The famous story of the retired sea-captain on the island who takes his time from the watchmaker in town only to find out that the watchmaker uses the sea-captains cannon shots at 12 noon each day to set his own clocks! [Attributed to Harrison (MIT) by Petley.]" Without the quotes it's a bit further down the list. But I agree it's not easy to find. that is not even the watchmaker involved ...that shop is on some Spanish island .... sorry Sevilla..... https://www.google.com/maps/place/El...2!4d-5.9947404 |
Zanzibar effect
On 22/08/2020 20:04, NY wrote:
Despite doing physics to A level and then elec eng at university, I've never heard of it before today, either by name or as a story, though I've heard many times of circular calibration. Ditto. Another term I heard at university applied to the problem of machines measuring strain versus stress being in error by bending themselves, was 'a soft machine' whether this was a well known term or a joke by the lecturer relative to the jazz band...I do not know. -- Progress is precisely that which rules and regulations did not foresee, Ludwig von Mises |
Zanzibar effect
On 22/08/2020 22:30, Bob Eager wrote:
On Sat, 22 Aug 2020 17:45:15 +0100, NY wrote: I can understand the problem of circular calibration, but I'd never have been able to discover or even guess what it was from the phrase, assuming I hadn't already heard of it. Nor me. At first, I assumed it was to do with overpopulation (some may recognose the reference). Oh yes. Stand on Zanzibar, or Soylent Green... -- Karl Marx said religion is the opium of the people. But Marxism is the crack cocaine. |
Zanzibar effect
On 22/08/2020 18:45, NY wrote:
"Jim GM4 DHJ ..." wrote in message ... On 22/08/2020 17:45, NY wrote: "Chris Hogg" wrote in message ... On Sat, 22 Aug 2020 14:58:08 +0100, "NY" wrote: "Jim GM4DHJ ..." wrote in message ... who has got caught out by the Zanzibar effect when calibrating things..me for one What is the Zanzibar effect? I can't find anything on Google so it's evidently not a widely-known term. Zanzibar time : https://tinyurl.com/suqbk29 Basically, a circular calibration process. A calibrates his instrument against an instrument owned by B, who unbeknown to A, calibrates his instrument against A's. Interesting that googling for the phrase as quoted "zanzibar effect" does not produce any matches. Lots of matches for the country of that name, but nothing else. Even googling for "zanzibar time" or "zanzibar effect time" doesn't produce any matches. I can understand the problem of circular calibration, but I'd never have been able to discover or even guess what it was from the phrase, assuming I hadn't already heard of it. https://metrology.wordpress.com/stat...-traceability/ Yes, there are references out there. It's strange that none of them (as far as I can find) seem to be findable by Google. Was there anyone else who's read this thread who had never heard of it and yet was able to find out what it meant? Am I just crap at being able to "drive" Google? I had to Google it, but used the term 'zanzibar effect calibration' with no quotes. Perhaps your driving skills do need honing ;) |
Zanzibar effect
On 22/08/2020 18:45, NY wrote:
"Jim GM4 DHJ ..." wrote in message ... On 22/08/2020 17:45, NY wrote: "Chris Hogg" wrote in message ... On Sat, 22 Aug 2020 14:58:08 +0100, "NY" wrote: "Jim GM4DHJ ..." wrote in message ... who has got caught out by the Zanzibar effect when calibrating things..me for one What is the Zanzibar effect? I can't find anything on Google so it's evidently not a widely-known term. Zanzibar time : https://tinyurl.com/suqbk29 Basically, a circular calibration process. A calibrates his instrument against an instrument owned by B, who unbeknown to A, calibrates his instrument against A's. Interesting that googling for the phrase as quoted "zanzibar effect" does not produce any matches. Lots of matches for the country of that name, but nothing else. Even googling for "zanzibar time" or "zanzibar effect time" doesn't produce any matches. I can understand the problem of circular calibration, but I'd never have been able to discover or even guess what it was from the phrase, assuming I hadn't already heard of it. https://metrology.wordpress.com/stat...-traceability/ Yes, there are references out there. It's strange that none of them (as far as I can find) seem to be findable by Google. Was there anyone else who's read this thread who had never heard of it and yet was able to find out what it meant? Am I just crap at being able to "drive" Google? When I search for "Zanzibar effect", the sea captain reference is the third item on the list, after the revolution on the island and the Wiki entry. |
Zanzibar effect
On 23/08/2020 09:29, Richard wrote:
On 22/08/2020 18:45, NY wrote: "Jim GM4 DHJ ..." wrote in message ... On 22/08/2020 17:45, NY wrote: "Chris Hogg" wrote in message ... On Sat, 22 Aug 2020 14:58:08 +0100, "NY" wrote: "Jim GM4DHJ ..." wrote in message ... who has got caught out by the Zanzibar effect when calibrating things..me for one What is the Zanzibar effect? I can't find anything on Google so it's evidently not a widely-known term. Zanzibar time : https://tinyurl.com/suqbk29 Basically, a circular calibration process. A calibrates his instrument against an instrument owned by B, who unbeknown to A, calibrates his instrument against A's. Interesting that googling for the phrase as quoted "zanzibar effect" does not produce any matches. Lots of matches for the country of that name, but nothing else. Even googling for "zanzibar time" or "zanzibar effect time" doesn't produce any matches. I can understand the problem of circular calibration, but I'd never have been able to discover or even guess what it was from the phrase, assuming I hadn't already heard of it. https://metrology.wordpress.com/stat...-traceability/ Yes, there are references out there. It's strange that none of them (as far as I can find) seem to be findable by Google. Was there anyone else who's read this thread who had never heard of it and yet was able to find out what it meant? Am I just crap at being able to "drive" Google? I had to Google it, but used the term 'zanzibar effect calibration' with no quotes. Perhaps your driving skills do need honing ;) OK for me, but perhaps the fact that people are now searching is an example of the Zanzibar effect !! |
Zanzibar effect
On 22/08/2020 18:34, Max Demian wrote:
On 22/08/2020 17:45, NY wrote: "Chris Hogg" wrote in message ... On Sat, 22 Aug 2020 14:58:08 +0100, "NY" wrote: What is the Zanzibar effect? I can't find anything on Google so it's evidently not a widely-known term. Zanzibar time : https://tinyurl.com/suqbk29 Basically, a circular calibration process. A calibrates his instrument against an instrument owned by B, who unbeknown to A, calibrates his instrument against A's. Interesting that googling for the phrase as quoted "zanzibar effect" does not produce any matches. Lots of matches for the country of that name, but nothing else. Even googling for "zanzibar time" or "zanzibar effect time" doesn't produce any matches. I can understand the problem of circular calibration, but I'd never have been able to discover or even guess what it was from the phrase, assuming I hadn't already heard of it. "Zanzibar effect" (with the quotes) gives (me) this as the first result: https://metrology.wordpress.com/stat...-traceability/ "The famous story of the retired sea-captain on the island who takes his time from the watchmaker in town only to find out that the watchmaker uses the sea-captains cannon shots at 12 noon each day to set his own clocks! [Attributed to Harrison (MIT) by Petley.]" Without the quotes it's a bit further down the list. But I agree it's not easy to find. Schrodingers cat effect ? |
Zanzibar effect
On Sun, 23 Aug 2020 06:39:09 +0100, "Jim GM4DHJ ..."
wrote: snip just used radio 4 on 198 Kc/s Icom rigs drift off frequency because they use cheap variable resistors.... So, Crazy Jim, you don't use Hertz because he was a foreigner yet you use a French unit symbol for temperature (Kelvin) instead of the unit k (to represent kilo / thousand) when you could have just put three zeros on yer number, using a capital K when it should be a lower but can't put a capital at the beginning of a sentence. Or maybe Kc/s are a measure of frequency drift with temperature you invented? Cheers, T i m |
Zanzibar effect
On 23/08/2020 09:52, Andrew wrote:
On 23/08/2020 09:29, Richard wrote: On 22/08/2020 18:45, NY wrote: "Jim GM4 DHJ ..." wrote in message ... On 22/08/2020 17:45, NY wrote: "Chris Hogg" wrote in message ... On Sat, 22 Aug 2020 14:58:08 +0100, "NY" wrote: "Jim GM4DHJ ..." wrote in message ... who has got caught out by the Zanzibar effect when calibrating things..me for one What is the Zanzibar effect? I can't find anything on Google so it's evidently not a widely-known term. Zanzibar time : https://tinyurl.com/suqbk29 Basically, a circular calibration process. A calibrates his instrument against an instrument owned by B, who unbeknown to A, calibrates his instrument against A's. Interesting that googling for the phrase as quoted "zanzibar effect" does not produce any matches. Lots of matches for the country of that name, but nothing else. Even googling for "zanzibar time" or "zanzibar effect time" doesn't produce any matches. I can understand the problem of circular calibration, but I'd never have been able to discover or even guess what it was from the phrase, assuming I hadn't already heard of it. https://metrology.wordpress.com/stat...-traceability/ Yes, there are references out there. It's strange that none of them (as far as I can find) seem to be findable by Google. Was there anyone else who's read this thread who had never heard of it and yet was able to find out what it meant? Am I just crap at being able to "drive" Google? I had to Google it, but used the term 'zanzibar effect calibration' with no quotes. Perhaps your driving skills do need honing ;) OK for me, but perhaps the fact that people are now searching is an example of the Zanzibar effect !! I used the term on day one of the OP and it's unlikely that there are enough followers of this thread to influence the engine. https://trends.google.com/trends/exp...zibar%20effect |
Zanzibar effect
On 23/08/2020 11:02, Richard wrote:
On 23/08/2020 09:52, Andrew wrote: On 23/08/2020 09:29, Richard wrote: On 22/08/2020 18:45, NY wrote: "Jim GM4 DHJ ..." wrote in message ... On 22/08/2020 17:45, NY wrote: "Chris Hogg" wrote in message ... On Sat, 22 Aug 2020 14:58:08 +0100, "NY" wrote: "Jim GM4DHJ ..." wrote in message ... who has got caught out by the Zanzibar effect when calibrating things..me for one What is the Zanzibar effect? I can't find anything on Google so it's evidently not a widely-known term. Zanzibar time : https://tinyurl.com/suqbk29 Basically, a circular calibration process. A calibrates his instrument against an instrument owned by B, who unbeknown to A, calibrates his instrument against A's. Interesting that googling for the phrase as quoted "zanzibar effect" does not produce any matches. Lots of matches for the country of that name, but nothing else. Even googling for "zanzibar time" or "zanzibar effect time" doesn't produce any matches. I can understand the problem of circular calibration, but I'd never have been able to discover or even guess what it was from the phrase, assuming I hadn't already heard of it. https://metrology.wordpress.com/stat...-traceability/ Yes, there are references out there. It's strange that none of them (as far as I can find) seem to be findable by Google. Was there anyone else who's read this thread who had never heard of it and yet was able to find out what it meant? Am I just crap at being able to "drive" Google? I had to Google it, but used the term 'zanzibar effect calibration' with no quotes. Perhaps your driving skills do need honing ;) OK for me, but perhaps the fact that people are now searching is an example of the Zanzibar effect !! I used the term on day one of the OP and it's unlikely that there are enough followers of this thread to influence the engine. https://trends.google.com/trends/exp...zibar%20effect nice to be able to edumacate peoples .... |
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