AeroPod, PowerPod and Newton

Questions:
- The “cal wind” number is dimensionless in the Newton display. If the “cal wind” shows +2.1, is that the same as a +2.1 km/h "offset"?...so when riding on a wind free day I will see a (false) +2.1 km/h headwind?
- If the cal wind shows -4.0, but I don’t do a “cal wind” before a ride, how much error will this cause the wind measurement in percent (%)?
- When is it recommended to do another “cal wind”?...when when the number is above 0.1 or 1.0 or 10.0 or 100.0 ?
- Is the “cal wind” temperature depended? If so, at what temperature difference is it recommended to do another “cal wind”?

Background:
I have always seen +/- 2-5 “cal wind” number after a ride when I do “cal wind” before a ride. Then I found that the Newton needs some time to cool down to outside temperature, so I started to do my cal wind after a few km's, but still saw "large" cal wind offset numbers after a ride. Then I started to do the cal wind after a ride, and found this a bit better, but then I saw “large” offset numbers before the next ride a few days later.

It's winter in my country. I store my Newton in the refrigerator a few hour before a ride, because the Newton needs 20-40 minutes to cool down to 0* Celsius from 24*C indoor temperature. Some days ago I did a test and did my "cal wind" outdoor in my garage (wind free) short after a long ride at around 0*C. After 10 minutes it still showed 0.0. I did a 10km ride, and it still showed 0.0-0.1. The next day I saw a +3 "cal wind" offset before the ride. It was -4*C outside. The Newton comes from the +5*C refrigerator environment. I ride for a few km's, stop and see the cal wind now is 0.0...perfect. I ride for 30km`s and then see the cal wind is around -3.6? I reset the cal wind to 0.0, ride another 10km's and now see a 0.0-0.2 cal wind number. I get inside and download the ride files. Inside it's 24* Celsius. After 20minutes the cal wind is +7.2-8.4.......

The cal wind number is a "pressure" value.

So, cool your unit down to the ambient temperature and do a cal wind offset. Don't bother doing another one until there is a significant change in the seasonal temperature. Don't worry about the changes throughout the ride. Newton handles this automatically. And even if you see a +3 or -3 at the end of the ride, Newton has taken the temp change into account.

The only time I do another wind cal is when it is consistently 10°C higher or lower. Then I will do another offset and leave it alone. So for me luckily that means I do a wind cal in May and don't do another one until almost November.

Don't chase the numbers.

racerfern wrote:The cal wind number is a "pressure" value.

So, cool your unit down to the ambient temperature and do a cal wind offset. Don't bother doing another one until there is a significant change in the seasonal temperature. Don't worry about the changes throughout the ride. Newton handles this automatically. And even if you see a +3 or -3 at the end of the ride, Newton has taken the temp change into account.

The only time I do another wind cal is when it is consistently 10°C higher or lower. Then I will do another offset and leave it alone. So for me luckily that means I do a wind cal in May and don't do another one until almost November.

Don't chase the numbers.

Thanks for the feedback.
"Don't chase the numbers" Isn't this just what we do?....chasing the (wattage) numbers while riding, or else we don't need the Ibike Newton

I really miss the practical information in the Ibike manuals, like "the cal wind number is in pascal, not km/h", "Do only another wind cal if above 3.0", "Ibike take care of wind offset changes while riding", "Do another cal if temp 10*c or more"....
As long as users don't know what -7.4 in the cal wind window is and the consequences of large offset numbers, users will chase the optimal settings (not the numbers).