very cheap Weston pile for sale in France AOIP  - Page 1
Forum section: electronics / general

author: Overspeed
author_rank: Frequent Contributor
timestamp: October 18, 2024, 07:48:48 am
content: HelloPerhaps that can be interesting for 30 Euro there is two samples for salehttps://www.leboncoin.fr/ad/collection/2847215844RegardsOS

author: Gyro
author_rank: Super Contributor
timestamp: October 18, 2024, 08:00:33 pm
content: At a specified output of 1,0191V, they will be Unsaturated Weston Standard cells. Being unsaturated, they will display very low temperature coefficient, however on the downside, their output voltage decays with time and, depending on how old they are, may have dropped below the level where they can be calibrated (around 1.0183V). They drop by around 80uV per year.Saturated cells, by comparison, are around 1.01860 at 20'C and have higher temperature coefficient (about -40uV/'C) but maintain a constant voltage until their rated capacity has been exhausted. Until this happens, they seem to have an extremely long life.Both types can be damaged by excessive current draw but depending on age, and how long ago commercial production ceased, unsaturated cells are probably of decorative / hazardous waste value by now. They will need periodic calibration at least.EDIT: I see that the cell is marked 1.0155V, that puts it in the hazardous waste category (it's not very attractive).

author: Overspeed
author_rank: Frequent Contributor
timestamp: October 19, 2024, 07:33:49 am
content: HelloI agree on your comment , that more a collectable artefact than a ''usable'' equipment included with a manufacturing year shall be in the 70's or perhaps also a sample to make reverse engineering .Regarding ''toxic waste'' even a classic mercury barometer is now a ''toxic waste'' and a lot of things are now '' classified '' dangerous . That the same with asbestos , a funny fact is most of the greatest French wines have been filtered by using asbestos up to the 70's .RegardsOS

author: Gyro
author_rank: Super Contributor
timestamp: October 19, 2024, 10:55:00 am
content: Quote from: Overspeed on October 19, 2024, 07:33:49 amIn the case of Weston cells, it's Mercury and Cadmium compounds (not just metallic form), a double whammy. [Edit: The seller has a disposal (and shipping, if he's honest) problem.]Wartime gas masks had Asbestos fibers in their filters. We shudder at such things these days.

author: Overspeed
author_rank: Frequent Contributor
timestamp: October 19, 2024, 07:04:30 pm
content: Helloa standard cell is small the quantity of chemical as the cell is small , so ok that toxic and the seller shall ...I link a complete documentation on Weston cells and Clark cells , there is drawing with main dims of a Weston cell .Weston cell stay a historic device as voltage reference .RegardsOS

author: bastl_r
author_rank: Regular Contributor
timestamp: October 19, 2024, 10:20:27 pm
content: Quote from: Gyro on October 19, 2024, 10:55:00 amHow could all these great scientists become so old when they were not protected and warned against such dangerous chemicals?Without this, fortunately late realization, we would probably still be working with stone tools today.

author: trobbins
author_rank: Frequent Contributor
timestamp: October 19, 2024, 10:55:41 pm
content: It certainly does take time for a population's mindsets to take on board modern safety practices. Perhaps it is that many older people don't like and don't want to accept change, along with a few gung-ho younger folk who defer to some of those older folk.

author: Overspeed
author_rank: Frequent Contributor
timestamp: October 20, 2024, 07:18:29 am
content: Quote from: trobbins on October 19, 2024, 10:55:41 pmHelloA bit out of the metrology subject but ......It s also a bit surprising to see heavily polluted areas by dangerous chemicals stay without cleaning as the '' petardage '' done after WWI in France when they have destroyed WWI chemical weapon in open field .... with as result a land destroyed or some test site as Monronvilliers ( near Reims ) where you can crop heavy metal and radioactive metal in the field ... as the nuclear test range was in use since the 50's without too much control . In UK Windscale nuclear plant is another case ... .https://www.francebleu.fr/infos/environnement/meuse-la-place-a-gaz-de-la-foret-de-spincourt-ou-les-vestiges-toxiques-de-la-grande-guerre-1620648928In some place in France and Belgium you can reach 17 kilogram of Arsenic per cubic meter of soil not included other product as mercury , The Baltic sea is polluted by 43000 tons of military crap most are chemical weapons ... examples are numerous.The actual problem seems to make lot of noise on details but avoid to solve massive existing problems.RegardsOS

author: Conrad Hoffman
author_rank: Super Contributor
timestamp: October 21, 2024, 05:11:14 pm
content: Because unsaturated cells degrade and it's been so long since they've been manufactured, IMHO,nonecan be considered good today. Saturated cells, OTOH, can go a hundred years or more, so if you can find any, and temperature control them, they can be an excellent low noise reference.

author: tggzzz
author_rank: Super Contributor
timestamp: October 21, 2024, 06:46:44 pm
content: Quote from: Conrad Hoffman on October 21, 2024, 05:11:14 pmExcept, to everybody's amazement...https://www.eevblog.com/forum/metrology/1000-my-(hi)story-of-the-weston-cell-of-the-volt-and-of-being-a-volt-nuts/msg4246351/#msg4246351

author: Conrad Hoffman
author_rank: Super Contributor
timestamp: October 21, 2024, 08:45:41 pm
content: Yes, quite a few appear to be good, but track them for a longer period of time and they tend to wander more than they should. I had a half a dozen Eppley and other cells and all succumbed to instability quite a few years ago, in spite of near perfect storage conditions.

author: guenthert
author_rank: Frequent Contributor
timestamp: October 22, 2024, 07:44:15 am
content: Quote from: Conrad Hoffman on October 21, 2024, 05:11:14 pmHow 'bout saturated cell(s) in a temperature controlled case, which isn't powered most of the time, i.e. the temperature varies when not "in use"? I know sat. cells die at "high" temperatures (some 40°C), but how stable are they, if exposed to varying "room" temperature between measurements?

author: Conrad Hoffman
author_rank: Super Contributor
timestamp: October 22, 2024, 01:24:43 pm
content: Saturated cells can last a very long time if the initial construction was good. Even the Julie Research boxes, which ran at 37C didn't have much problem. I don't think there's much actual data on how long is long, because it's so long.

author: dseyst
author_rank: Contributor
timestamp: October 23, 2024, 07:50:21 pm
content: I have 14 unsaturated standard cells. Some of them are seemingly still good.The five best read as follows:3/31/22876649 1.018833876650 1.018860879590 1.019036879591 1.018976880173 1.01898510/23/24876649 1.018864876650 1.018863879590 1.019038879591 1.018948880173 1.018960There was an approximate 3 degree temperature difference from the readings taken in 2022 and the latest readings taken this morning.

author: bat
author_rank: Regular Contributor
timestamp: October 25, 2024, 09:17:40 am
content: I have a AOIP temperature sensor that we use to calibrate our PT100 & thermocouple sensors. Despite it's age, this AOIP sensor has incredible performances and over the years there is little to no temperature drift. It's calibrated every year for it's COFRAC accreditation.

author: Overspeed
author_rank: Frequent Contributor
timestamp: October 25, 2024, 01:11:39 pm
content: Quote from: bat on October 25, 2024, 09:17:40 amHelloI have a full batch of AOIP equipment as calibrator , data acquisition system , simulator and other stuff ..) quality is impressive except their plastic enclosures which feel / look a bit cheap but that work fine.RegardsOS

author: Overspeed
author_rank: Frequent Contributor
timestamp: November 03, 2024, 07:17:14 pm
content: Helloa set of pictures for a Tinsley autopsyRegardsOS