Some tips on where to place the device
NAM case is not fully waterproof. In the bottom there are holes which are necessary to let air flow out of device. Thus You can not place device where it can be reached by splashing raindrops. If You place it low over windowsill in heavy rain water can get inside case.
This is the reason You have to mount device while keeping it level (the HECA housing should face downwards). When level is maintained raindrops will flow to the bottom and drop on lower edges of case. If the case is crooked, waterdrops will run down the bottom and water can get inside the case. You don't have use some laser tools, spirit level will be enough.
We have tested devices both with protection sticker and without. Even in direct sunlight, without sticker temperature inside the case have not exceed allowed maximum for devices. But remember that was tested in Warsaw, Poland. If Your device will be placed in southern European countries that may not be true anymore. So, we recommend always to use protection sticker (added to each NAM).
The other topic are temperature readings in sunlight. It is quite obvious that device placed on sun will show much higher temperature. Ideally it would be to place it in Stevenson screen but any place with shadow will be OK. Any wall facing north is good location for NAM.
Always place protection sticker on NAM case and avoid placing device in sunny place.
In our opinion NAM provides most relevant information if it measures air used by us to inhale. So it does not make much sense to mount it on high wall, 10 meter over ground level. 2-3 meters over ground is optimal. Also choose place where thers no wind tunnels between buildings. We don't have mention ventilation outlets are also places to avoid?
If You place NAM where smoking is allowed - cigarette smoke may impact readings.