Radiation Screens

[Richard]

Up till recently i had had my max-min gauge and a digital sensor in where it was in all day shade,where it was well away from any radiated heat as in buildings,bare ground etc,it also was where it had good wind flow,i had always thought that this would have given a close to accurate reading, it wasn't till the max-min gauge went into a new radiation screen that i not only noticed a two to three difference in temp from where it was originally positioned but there was now same difference between the digital sensor and gauge,i then placed the censor inside the screen to see what would happen and it too dropped 2-3 deg.This surprised me,i thought that digital sensors were designed to be able to be placed any where where its shady and be accurate,clearly not , most people that buy those cheaper weather stations are not getting a true reading if they are not in a screen.

[Tornado Tim]

most people that buy those weather stations are not getting a true reading if they are not in a screen.

Most cheaper weather stations..... around $200... ie Lacrosse, WH1080 etc, most of the Radiation shields are not UV treated and the shields are far to small and the gaps are too big between the plates.
Which means it lets in the sun and when it heats up the plastic the plastic radiates back into the shield making the temps High.
Even a DIY shield made out of plastic bowls is much better..... They compare well to the Davis and Viasala stations.

Of note: I see NIWA has put a Viasala WXT520 Weather Station up in the Auckland Islands, will be good indicator of whats to come when the Low pressures become more polar orientated.

[NZstorm]

Of note: I see NIWA has put a Viasala WXT520 Weather Station up in the Auckland Islands, will be good indicator of whats to come when the Low pressures become more polar orientated.

Met Service have that AWS on Enderby Island 93929 which is in the Auckland Islands.

On the topic of temperature, it would be the hardest met parameter to measure accurately.

[Nev]

Sorry for getting a little O.T. here, but yes, MS have been running its AWS on Enderby Island on the northern Auckland Islands since late 1991. However, NIWA's new EWS (or CWS? - Compact Weather Station) is inland from Smith Harbour in the centre of the main island, and will probably give a better indication of local environmental conditions, including (for what it's worth) sunshine hours.