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EU Regulations cause headache for myself and UK MET


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Posted
  • Location: Sheffield South Yorkshire 160M Powering the Sheffield Shield
  • Weather Preferences: Any Extreme
  • Location: Sheffield South Yorkshire 160M Powering the Sheffield Shield

The EU in it's wisdom has banned mercury. Doesn't sound to bad. However I found out this morning after breaking my Maximum thermometer that I can't buy a replacement legally.  Well I can but not one with the required accuracy and although i can import this may get seized by customs.

 

Thank you EU.

 

 

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Posted
  • Location: Longlevens, 16m ASL (H)/Bradley Stoke, 75m ASL (W)
  • Weather Preferences: Hot sunny summers, cold snowy winters
  • Location: Longlevens, 16m ASL (H)/Bradley Stoke, 75m ASL (W)

I'm not surprised in the least

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Posted
  • Location: Cheddington, Buckinghamshire
  • Weather Preferences: Winter: Cold & Snowy, Summer: Just not hot
  • Location: Cheddington, Buckinghamshire

It's been banned for years.

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Posted
  • Location: Sheffield South Yorkshire 160M Powering the Sheffield Shield
  • Weather Preferences: Any Extreme
  • Location: Sheffield South Yorkshire 160M Powering the Sheffield Shield

Well I was able to buy a mercury thermometer fairly recently. I think the ban has been coming in stages.

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Posted
  • Location: Cheddington, Buckinghamshire
  • Weather Preferences: Winter: Cold & Snowy, Summer: Just not hot
  • Location: Cheddington, Buckinghamshire

Banned since 2007 it seems. There are mercury alternatives though.

 

Whenever I've taken observations from a weather station, it wasn't using a mercury thermometer. So it's not causing a problem for the Met Office.

Edited by Nick L
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Posted
  • Location: Sheffield South Yorkshire 160M Powering the Sheffield Shield
  • Weather Preferences: Any Extreme
  • Location: Sheffield South Yorkshire 160M Powering the Sheffield Shield

Banned since 2007 it seems. There are mercury alternatives though.

I've bought three or four since 2007 so no the ban has only recently come into play.

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Posted
  • Location: Cheddington, Buckinghamshire
  • Weather Preferences: Winter: Cold & Snowy, Summer: Just not hot
  • Location: Cheddington, Buckinghamshire

I've bought three or four since 2007 so no the ban has only recently come into play.

 

Why does it need to be mercury anyway? Like I said, there are alternatives which do the job just as well.

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Posted
  • Location: Sheffield South Yorkshire 160M Powering the Sheffield Shield
  • Weather Preferences: Any Extreme
  • Location: Sheffield South Yorkshire 160M Powering the Sheffield Shield

Why does it need to be mercury anyway? Like I said, there are alternatives which do the job just as well.

Accuracy so I'm told.

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Posted
  • Location: Edmonton Alberta(via Chelmsford, Exeter & Calgary)
  • Weather Preferences: Sunshine and 15-25c
  • Location: Edmonton Alberta(via Chelmsford, Exeter & Calgary)

what's wrong with digital thermometers???

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Posted
  • Location: Sheffield South Yorkshire 160M Powering the Sheffield Shield
  • Weather Preferences: Any Extreme
  • Location: Sheffield South Yorkshire 160M Powering the Sheffield Shield

what's wrong with digital thermometers???

Interesting you should mention that. been looking at those most are far too inaccurate +/- 3c which is no good. I found some on an American site nist certified +/- 0.1C. Question is will they ship to UK.

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Posted
  • Location: just south of Doncaster, Sth Yorks
  • Location: just south of Doncaster, Sth Yorks

From memory we started using ert (electircal resistance thermometers) in UK Met in the, could have been late 60's certainly by the 70's. Mercury ones were still used for a time, cannot remember how long. I also seem to remember that the NPL (National Physics Laboratory) which checked all met equipment, T, and P for example used mercury for their accuracy checks. Maybe an e mail to them, if such a thing still exists. Grass and concrete thermometers, again I think, may have been mercury but possibly like some others used alcohol coloured liquid?

not sure if any of that helps?

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Posted
  • Location: Cromdale, Highland
  • Location: Cromdale, Highland

what's wrong with digital thermometers???

I run a Davis VP2, alongside a conventional Met-Office set-up within a Stevenson screen. I find that the Davis thermometer gives fairly accurate readings in the mid-range. However, once we get into the extremes of hot or cold weather, its accuracy drops off by a 1 or 2 degrees and regular calibration becomes essential.

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Posted
  • Location: Cheddington, Buckinghamshire
  • Weather Preferences: Winter: Cold & Snowy, Summer: Just not hot
  • Location: Cheddington, Buckinghamshire

From memory we started using ert (electircal resistance thermometers) in UK Met in the, could have been late 60's certainly by the 70's. Mercury ones were still used for a time, cannot remember how long. I also seem to remember that the NPL (National Physics Laboratory) which checked all met equipment, T, and P for example used mercury for their accuracy checks. Maybe an e mail to them, if such a thing still exists. Grass and concrete thermometers, again I think, may have been mercury but possibly like some others used alcohol coloured liquid?

not sure if any of that helps?

 

I'm pretty sure the ones we used at uni were alcohol with red dye or something like that.

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Posted
  • Location: Skirlaugh, East Yorkshire
  • Location: Skirlaugh, East Yorkshire

I run a Davis VP2, alongside a conventional Met-Office set-up within a Stevenson screen. I find that the Davis thermometer gives fairly accurate readings in the mid-range. However, once we get into the extremes of hot or cold weather, its accuracy drops off by a 1 or 2 degrees and regular calibration becomes essential.

That's more to do with the sensor in the station. Although Davis list +/-0.5C, in reality it isn't:

 

http://www.sensirion.com/fileadmin/user_upload/customers/sensirion/Dokumente/Humidity/Sensirion_Humidity_SHT1x_Datasheet_V5.pdf

 

The Davis is the SHT11, so at 0C it could be as much as 1.2C out. I've replaced mine with a custom unit which uses the SHT15 sensor which is much more accurate. In typical UK temperatures its never going to be more than around 0.7C out at worst.

 

I must have got lucky with my SHT15 though, as when checking with a calibration probe from work it was exactly correct at 0C, 10C and 20C. My standard SHT11 Davis sensor was +0.6C, +0.4C and +0.5C out for reference.

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Posted
  • Location: Cromdale, Highland
  • Location: Cromdale, Highland

That's more to do with the sensor in the station. Although Davis list +/-0.5C, in reality it isn't:

 

http://www.sensirion.com/fileadmin/user_upload/customers/sensirion/Dokumente/Humidity/Sensirion_Humidity_SHT1x_Datasheet_V5.pdf

 

The Davis is the SHT11, so at 0C it could be as much as 1.2C out. I've replaced mine with a custom unit which uses the SHT15 sensor which is much more accurate. In typical UK temperatures its never going to be more than around 0.7C out at worst.

 

I must have got lucky with my SHT15 though, as when checking with a calibration probe from work it was exactly correct at 0C, 10C and 20C. My standard SHT11 Davis sensor was +0.6C, +0.4C and +0.5C out for reference.

Thanks for that, and very interesting too - a pity really that Davis, with such a sensor readily available, don't fit it in the first place.

Edited by speyweather
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Posted
  • Location: Skirlaugh, East Yorkshire
  • Location: Skirlaugh, East Yorkshire

Thanks for that, and very interesting too - a pity really that Davis, with such a sensor readily available, don't fit it in the first place.

 

From last September they have offered it as a replacement, its the part #7346.174.

 

I haven't seen any in the wild yet though and its probably going to be £150+ in the UK going by the fact the standard replacement is £120.

Edited by reef
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Posted
  • Location: East Devon
  • Location: East Devon

From last September they have offered it as a replacement, its the part #7346.174.

 

I haven't seen any in the wild yet though and its probably going to be £150+ in the UK going by the fact the standard replacement is £120.

 

That's interesting I didn't know that and would certainly like the higher spec sensor.. but not sure I'd pay that price for it (unless mine failed anyway and there were no much cheaper homebrew ones around). I think I have been lucky on the temperature front, the two SHT11 sensors I've had agree within 0.1c of each other, but my current one reads a bit high on humidity apart from not going above 97 or 98%. Dew-point is often up to 2C above the Exeter Airport MetO station.

 

I did get a custom SHT15 (actually SHT75) from Ebay to replace a failed sensor in my old (backup) ISS, which is usually 0.1c above the current SHT11 but think I was unlucky as its humidity doesn't go above 93%... and I since realised there was a better potential source of a homebrew sensor in the UK.

 

Another thing I want to do is solve the problem of the fan not running some of the time. Feeding a constant AC supply is unlikely to be practical with me so am thinking of carefully 'modifying' the radiation shield to make it less enclosed for when the fan ain't running.. but not sure how sensible that is and not sure what else I can do.

Edited by Evening thunder
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  • 2 months later...
Posted
  • Location: Sheffield South Yorkshire 160M Powering the Sheffield Shield
  • Weather Preferences: Any Extreme
  • Location: Sheffield South Yorkshire 160M Powering the Sheffield Shield

Well no luck on the digital side. Thought I found one bought it faulty on arrival but wouldn't do a 24 hour check. Replaced the Davis sensor with a sh15 unit which instantly fixed the humidity readings which were off. Time will tell with the temp sensor.

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