Some of our temperature and humidity sensors live in a nice (blue) Ikea cup for protection against direct exposure to weather / rain. However, good rain protection does not necessarily mean good sun protection: With direct sun light on the cup, it acts like a green house so you have to shadow it.
Ja, der hängt nicht optimal oder der Wetterschutz ist nicht geeignet. Der Sensor mit Becher war am Anfang im Süden, da ich dachte die Temperatur am Flugloch sei interessant, da waren die Ausreisser noch extremer. Osten wäre vermutlich eine gute Option, da sollte nur mäßig Sonne sein, Kabel ist aber zu kurz oder ich müsste die Box mit der Solarzelle umsetzen zwischen zwei Beuten.
There is another of-the-shelf-weather-enclusure, a bit less expensive (starting at 10€) and available at german distributors: TFA Dostmann 98.1114.02 Protective Cover for Outdoor Transmitter
Ok, my Ikea-cup as weather protection is not good, but the
luftdaten-info AirRohr seems to be same sh… suboptimal regarding direct solar radiation.
My dust sensor is mounted on the balcony. The balcony is on the south side of the house but has a small wall on the right and left side. The sensor is mounted on the right side. So morning sun can reach the housing up to noon directly. Aaaand unfortunately you can see this very nicely in the data:
This data are from today (2019-02-27), eo February, no “Jahrhundertsommer” only wrong measurements due to greenhouse effects:
And not only today, faultily data the last days also!
Of course! Both are housing with only the bottom open. Ther is no circulation or exchange with the surrounding air possible. And where shall warm air float to, after it started floating up? And both housings are “dark”.
(My test-setup between AirRohr and a weather-housing hasn’t made it so far to an outdoor or “evenly sun-flooded” position.)
I think we are talking about different thinks. (1) an official and “good” semi-professional weather station. And (2) a sensor placed on an easy reachable place without too much effort for additional hardware. So in case you must / like to place it on the bee hive or your balcony wall, take the dark side of the force ahm, balcony!
If you put it in blue plastic cup, I don’t care anyhow – if I know that’s the case (I want to know.). but I still challenge that for a “proper” weatherhousing (10euro)!
but if the air around your hive is widely heated through the big wall next to you, why don’t you want to know this “main” temperature but instead the probably cold corner behind your hive?
I don’t know if I understand the question corret. I fear that a sensor – eavenin a proper weather housing directly mounted on a hive with direct sun radiation will pick up a too high temperatur becaus the underground is heated up and the 5 cm away sensor will measure too high values. So it would be better to place the sensor in the shadow.
[edit: sorry, I misunderstood the idea of "on the top of a (netal-plated) roof. I understood it like “in front of the hive in direct sunlight”]
But that’s exactly whats supposed to happen! Please have a look at some DWD temperature-readings from ten days in the last summer:
White line = air temperature (2m),
brown line = temperature in 5cm.
One is supposed see when the sun heatens the ground much more than the air during a day with sunlight – and that the ground cools the 5cm-air-temperature much more down during the night.
But the DWD “sees” this temperature above a green lawn, whereas in most cases the roof of a hive is made of folded galvanized sheet steel resulting in much higher temperatures - you won’t touch this in summer. Furthermore, a temperature taken there only says something about a 1/4 m² sheet of metal, these readings would have no use.
jep, sorry, I wasn’t really aware about the above&metal-part.
i would prefer a spot on the ground probably a meter in south orientation to the hive, measured 5cm above “natural soil” with no vegetation.
in addidation we could think about a custom level like “50cm above (green?) soil”, or just as “at the hive’s entrance” and I would not care about sunlight as long as the device is in a proper housing.
[edit: The 5cm-reading is above “natural soil, no vegetation”, but the 2m-reading is “above lawn”.]
Ja, das Ding ist Mist. Viel zu wenig Luftaustausch möglich, dafür stehen zu Lamellen zu eng beinander und sind zu lang. Ist eher ne Limodose aus Plaste, aber mit Schlitzen.