Hello Rob, yes someone who has given thought yes if the calibration stamp is out of date then yes that would have to be re calibrated to confirm some outsource some do inhouse it all takes time.

as long its within the variables accepted the record will stand I cant make judgements about individual weather stations but can say data has to be correct to the above to go into the record books

Try to be patient folks

to confirm 

 

The point is, if it is an official station shouldn't it be regularly inspected and calibrated? Or do they only care if it's a record, and the rest of the time it can be as inaccurate was we like?

Hello Rob, yes someone who has given thought yes if the calibration stamp is out of date then yes that would have to be re calibrated to confirm some outsource some do inhouse it all takes time.

as long its within the variables accepted the record will stand I cant make judgements about individual weather stations but can say data has to be correct to the above to go into the record books

Try to be patient folks

to confirm 

No doubt you are correct, PL, but when shall we have a hot spell like this again? It is a bit of a meteorological disappointment, equivalent to finding you've left your condoms in the limousine as you make your way to the honeymoon suite...

Hello Rob, yes someone who has given thought yes if the calibration stamp is out of date then yes that would have to be re calibrated to confirm some outsource some do inhouse it all takes time.

Calibration is far less of an issue than exposure. The majority of erroneous temperature readings are down to where the thermometer is, not the thermometer itself. As had been discussed in this thread, changes to the exposure (e.g. grass v soil v knee-high weeds, surrounding buildings, trees, etc.) are what will likely be considered for yesterday's readings.

Sorry Rob did not answer this part usually has yearly calibration stamp on equipment with data card with inspectors number on the stamp

'

 

 

The point is, if it is an official station shouldn't it be regularly inspected and calibrated? Or do they only care if it's a record, and the rest of the time it can be as inaccurate was we like?

SR is part of the calibration.

Sorry folks I can see the other side of this as ive said for 4th time now it all takes time 

 

Calibration is far less of an issue than exposure. The majority of erroneous temperature readings are down to where the thermometer is, not the thermometer itself. As had been discussed in this thread, changes to the exposure (e.g. grass v soil v knee-high weeds, surrounding buildings, trees, etc.) are what will likely be considered for yesterday's readings.

 

No doubt you are correct, PL, but when shall we have a hot spell like this again? It is a bit of a meteorological disappointment, equivalent to finding you've left your condoms in the limousine as you make your way to the honeymoon suite...

It's a VAR moment, but yes that analogy works too 

Reminds me of the scottish temperature record that wasn't when the met office eventually decided someone had left a car too close to the station :-)

https://www.bbc.co.uk/news/uk-scotland-44725830

I recall that well. The media up here were all over it at the time as well.

To be fair Roger Procedures and Calibration are a must when entering into the record books we all want that info to be correct as possible a little time is not without reason prolong time I cant answer for I wish I could I would work late to clarify for what ever reason.

im sure we will know soon.

 

 

No doubt you are correct, PL, but when shall we have a hot spell like this again? It is a bit of a meteorological disappointment, equivalent to finding you've left your condoms in the limousine as you make your way to the honeymoon suite...

 

No doubt you are correct, PL, but when shall we have a hot spell like this again? It is a bit of a meteorological disappointment, equivalent to finding you've left your condoms in the limousine as you make your way to the honeymoon suite...

August?

August?

We can have another nice discussion about it.

 

Its apparently got a four start rating and was awarded a silver rosette last year. Still no mention from the MetOffice. This whole charade is a total embarrassment. I said it earlier, they need to stop spending money on their website and start to invest in the reporting network. 

Maybe this could be something to do with why the BBC's weather forecasting department terminated their decades-long association with the Met Office early last year and joined up with Meteogroup instead.

 

Its apparently got a four start rating and was awarded a silver rosette last year. Still no mention from the MetOffice. This whole charade is a total embarrassment. I said it earlier, they need to stop spending money on their website and start to invest in the reporting network. 

That doesn't necessarily mean much, as it happens. The star ratings are assigned based on the sensors etc you have, plus their exposire, and the rosette relates to how many days a year you've been uploading - heck, mine has a gold rosette, but it's in no way even close to being an official station!

The four star bit, for example, means the exposure of the instruments is one of these, quoting from the Met Office WOW site:

Exposure

• 5: Very open exposure: no obstructions within 10h or more of temperature or rainfall instruments.


• 4: Open exposure: most obstructions/heated buildings 5h or from temperature or rainfall instruments, none within 2h.


• 3: Standard exposure: no significant obstructions or heated buildings within 2h of temperature or rainfall instruments.

Exposure guidelines are based on a multiple of the height h of the obstruction above the sensor height; the standard is a minimum distance of twice the height (2h). Thus for a raingauge at 30 cm above ground, a building 5 m high should be at least 9.4 m distant (5 m less 0.3 m, x 2), and a 10 m building should be at least 17 m from a thermometer screen (10 m less 1.5 m, x2)

https://wow.metoffice.gov.uk/support/siteratings

Hello Darren Yes and one of the problems you can have is that the screen can actually create its own micro climate it may be stated that the larger the bulk of a screen, the stronger the microclimate within the screen and the more the sensed temperature deviates from the real air temperature any design of a thermometer screen is a result of compromises. Hense calibration  Finding the optimal design is a serious challenge   I dont think folk realise what goes into these things.

of

 

That doesn't necessarily mean much, as it happens. The star ratings are assigned based on the sensors etc you have, plus their exposire, and the rosette relates to how many days a year you've been uploading - heck, mine has a gold rosette, but it's in no way even close to being an official station!

The four star bit, for example, means the exposure of the instruments is one of these, quoting from the Met Office WOW site:

Exposure

• 5: Very open exposure: no obstructions within 10h or more of temperature or rainfall instruments.


• 4: Open exposure: most obstructions/heated buildings 5h or from temperature or rainfall instruments, none within 2h.


• 3: Standard exposure: no significant obstructions or heated buildings within 2h of temperature or rainfall instruments.

Exposure guidelines are based on a multiple of the height h of the obstruction above the sensor height; the standard is a minimum distance of twice the height (2h). Thus for a raingauge at 30 cm above ground, a building 5 m high should be at least 9.4 m distant (5 m less 0.3 m, x 2), and a 10 m building should be at least 17 m from a thermometer screen (10 m less 1.5 m, x2)

https://wow.metoffice.gov.uk/support/siteratings

 

Hello Darren Yes and one of the problems you can have is that the screen can actually create its own micro climate it may be stated that the larger the bulk of a screen, the stronger the microclimate within the screen and the more the sensed temperature deviates from the real air temperature any design of a thermometer screen is a result of compromises. Hense calibration  Finding the optimal design is a serious challenge   I dont think folk realise what goes into these things.

Funnily enough I had a quick look earlier at the Davis range of weather stations on a certain online shop - I know they're good quality, but I was surprised to see that they apparently don't need to be in a Stevenson screen (so presumably the Met Office-approved instruments are something else - wonder what brand they use?)

Then you get fan-aspirated options, daytime only or 24-hour and yes - calibration rears its head. The shop says, and I quote:

"Recalibrating the temperature humidity sensor in the field requires a visit to site from someone with a certified accurate sensor. This would need to be a reference instrument with an annual certificate from a UKAS test house. If you need to do this then we consider that it is actually more cost-effective to replace the temperature humidity sensor with a fresh one."

This will, doubtless, be what's happening at Cambridge as we speak (well, maybe on Monday!)

If a national record is to fall everything has to be absolutely 100% certain. Brogdale passed the checks in 2003, it remains to be seen whether Cambridge does as well.

 

Its apparently got a four start rating and was awarded a silver rosette last year. Still no mention from the MetOffice. This whole charade is a total embarrassment. I said it earlier, they need to stop spending money on their website and start to invest in the reporting network. 

I must admit I thought you were joking when I read this earlier today. No idea that stars and rosettes were dished out for weather stations.

Hello Darren Im not allowed to say, as the calibration firm i worked for made me sign a non/disclosed letter it meant that I worked for 18 months and got paid 5 years money I cant talk about names or certain met equipment I could not turn that down as i got a another job part-time to take me to retirement.

I can confirm the equipment you mention as very good.

 

Funnily enough I had a quick look earlier at the Davis range of weather stations on a certain online shop - I know they're good quality, but I was surprised to see that they apparently don't need to be in a Stevenson screen (so presumably the Met Office-approved instruments are something else - wonder what brand they use?)

Then you get fan-aspirated options, daytime only or 24-hour and yes - calibration rears its head. The shop says, and I quote:

"Recalibrating the temperature humidity sensor in the field requires a visit to site from someone with a certified accurate sensor. This would need to be a reference instrument with an annual certificate from a UKAS test house. If you need to do this then we consider that it is actually more cost-effective to replace the temperature humidity sensor with a fresh one."

This will, doubtless, be what's happening at Cambridge as we speak (well, maybe on Monday!)

If a national record is to fall everything has to be absolutely 100% certain. Brogdale passed the checks in 2003, it remains to be seen whether Cambridge does as well.

The report on the BBC News at Six has a report from the site. TBH it doesn't really clarify things a great deal but there IMO is nothing obviously wrong. The 1.5m rule mentioned (by Retron earlier) could well be passed, but it is difficult to be certain from the angle shown.  

The discussion on here really shows how hard it is to get a precise temperature reading on any sort of instrument, but it makes me wonder, are even 'calibrated' thermos really capable of reading the 'correct' temperature at any given point. Does a ultra precise temperature even exist in the real world?