I was thinking about something that would functionally resemble a Stevenson screen in miniature. It's been years since I experimented with the idea. I did measure (with a decent thermometer) in paper and a plastic enclosure, but I forgot what the outcome was. The thick white paper thing I made was difficult to mount, I basically had it trailing from a cord held in the hand. Awkward and not practical. How far will I go to just have temperature registration, that is only accurate to 1 degree (in the FIT file), I said to myself, this is going too far. So for years I made cuts in the underside of the fabric of a light colored hat's visor and shoved a Tempe inside. The fabric of the cap would sweat soak in minutes, so the Tempe was measuring a kind of 'wet bulb' temperature. Compensating for the radiant warmth from my head, I reasoned. Never measured accurately if this was the case.

I like the idea of a modified white plastic cap. I wonder if a silver painted cap would be better, reflecting more.

If only I had more time to play with these ideas!

Just going back to visors, I have 2 piieces of the previous version of this cap   https://www.compressport.com/inter/en/caps/753-running-cap-for-summer-7640314045903.html and they have reflective aluminium stripes. But even these caps did not give me those results I wanted.

The miniature Stevenson screen was much better provided you wore at least a thick waistbelt, but ideally a small running backpack or a bigger hiking backpack. If not then I had to rely on the cap visor, but the total weight and size of this gadget was too big to combine it with a visor. And really awkward. :-)

Anyway even a mini Stevenson screen can be warmed up after a while in direct sunshine if it is behind your back and not in front of you , at least it is what I think. The total amount of air flowing through it seems to be too low compared to the total volume of the solid outer material. If it is iin front of you much higher amount of air can be streaming through. That means the necessity of a pretty long visor :-)

So for years I made cuts in the underside of the fabric of a light colored hat's visor and shoved a Tempe inside. The fabric of the cap would sweat soak in minutes, so the Tempe was measuring a kind of 'wet bulb' temperature. Compensating for the radiant warmth from my head, I reasoned. Never measured accurately if this was the case.

Using water/sweat is an interesting idea, but since the humidity of the air is changing too much from day to day, and typically even within a day, the cooling effect of the evaporation is also far from being constant. Anyway you may be right that the humidity has effects at least in the same direction, if it is less then both the evaporation around Tempe is bigger and from your head more sweat can come off, thus more radiant warmth.

I am just not sure how you could manage to have a naturally wet visor, because as I remember I never sweat so much that my whole cap including visor become soaked.

The cig app is only showing real-time. Someone has to develop a new app and a data field, also for getting the temperature stored in the activity file…

Yes, the Ruuvi is actually designing for stationary use, but I was looking for possible already available/usable alternatives for hiking.

Tisztul_A_Visztula said:

I am just not sure how you could manage to have a naturally wet visor

The caps are extremely cheap thin (polyester I guess) and in summer it is usually quite humid so evaporation isn't quick. That, and I do indeed sweat like a pig. I avoid the gym because I spent half the time wiping whatever poor appliance has the bad luck of being my choice for cardio. Sorry for being gross! 

BTW I store one Tempe outside and grab that for use during runs, so it is already acclimatised to the outdoor temperature. 

Well since I have just :-) 3 Tempe and I use one for both hiking and running, I leave it on the last place I mounted. And quite often I dont start my runs from our house.It is why I asked the developer of “Tempe field”  ciq df to add a delay parameter for the use of current data for min/max/avg.

Btw today I bought 5 plastic cream jars in 3 sizes to produce the new version.

I even read about insulators and later I am going to buy some en.m.wikipedia.org/.../Aerogel, if it is available in small pieces, too. Because it is quite expensive.

Tisztul_A_Visztula said:

I feel some new motivation to manufacture a Tempe shield ver 2.0.

Jeez! The cover part of the largest jar was ok, but  the bottom was so thick that it was prone to crack. After I bought  and ruined two of them I had to buy  the same volumetric jar, but from another pharmacy. It had smaller top and height which created a lot of problems during the manufacturing. So I swore to all gods that I would never fabricate a version 3 unless version 2 would be perfect and version 3 would be a simple replacement.

I had no patience to drill nice holes or cut  nice curves with scissors.

2 pics of the top half of the Tempe shield, 2 of the bottom part:

And the nice looking small basket Snow White is holding in her dainty hand ;-)

Pretty and elegant ;-) I like your design.

Much better to make than what I have in mind now; a variation of this weather station screen, but far smaller and with only 3 'layers'. Currently busy turning the house over looking for thin white thermo-plastic material that I can cut into round shapes, deform using hot water to make convex saucers, then cut the center out and hot-glue them with something I need to find, to act as spacers. Yoghurt containers come to mind. These deform in the dishwasher at 70 Celcius. Maybe spoons would work as a mold. Or is this a good excuse to get a 3D printer?