Fenix 5 - temperature measurement

Oh, and being from Arizona, connecting my Tempe to my fenix (Phoenix) makes me smile. Maybe the next accessory will be called a Mesa or Chandler :D

As another AZ guy that uses a Tempe (in Phoenix and with a Fenix), I wonder if Garmin pronounces "Tempe" the same way as the city is pronounced here! :)

Is it just me, or does the temperature data make no sense? It's not even close to accurate during my workouts, about 10 degrees Celsius off. Also the changes in temperature during the workout make zero sense.

Will this be a software bug, or just inaccurate temp. sensor?

When worn away from the body (eg. mounted on my bike handlebars), I find it pretty accurate. When it's on my wrist, yes, it does get inflated by body temperature.

The exact purpose of it is to measure the temperature of the internal air pressure sensor. This info is used to calculate Elevation based on absolute pressure and the temperature at which it was measured by the internal sensor.
HTH

Elevation is based on pressure. Pressure is pressure is pressure. No need for temperature. However, elevation should by based on GPS.

Elevation is based on pressure. Pressure is pressure is pressure. No need for temperature. However, elevation should by based on GPS.

Elevation based on GPS is known to be quite bad. That's why GC uses "elevation correction" for non-baro devices as the default.

I see it myself when I wear a watch with a baro and one that uses GPS at the same time, and watch both. With an actual change that may be 40', the baro is pretty spot on, while on a GPS based device, it can show far more until elevation correction is done on GC. GPS can be a bit flaky when it comes to vertical distance.

Elevation is based on pressure. Pressure is pressure is pressure. No need for temperature.

All you have to do is google it to find out that the relationship between pressure and elevation does involve temperature.

Elevation is based on pressure. Pressure is pressure is pressure. No need for temperature. However, elevation should by based on GPS.

You are wrong.

Please explore the following calculator to clearly see the relationships between Elevation, Pressure and Temperature in calculating Mean Sea Level Pressure: http://keisan.casio.com/exec/system/1224575267

HTH

Elevation is based on pressure. Pressure is pressure is pressure. No need for temperature. However, elevation should by based on GPS.

As to your second point about using GPS for Elevation, you are also wrong.

Garmin's thoughts on the subject are as follows (https://support.garmin.com/faqSearch/en-GB/faq/content/QPc5x3ZFUv1QyoxITW2vZ6):

Understanding the accuracy of the GPS elevation reading
GPS heights are based on an ellipsoid (a mathematical representation of the earth's shape), while USGS map elevations are based on a vertical datum tied to the geoid (or what is commonly called mean sea level). Basically, these are two different systems, although they have a relationship that has been modeled.
The main source of error has to do with the arrangement of the satellite configurations during fix determinations. The earth blocks out satellites needed to get a good quality vertical measurement. Once the vertical datum is taken into account, the accuracy permitted by geometry considerations remains less than that of horizontal positions. It is not uncommon for satellite heights to be off from map elevations by +/- 400 ft. Use these values with caution when navigating.


A more detailed explanation can be found here: http://www.faculty.sfasu.edu/zhangy2/download/GPS_elevation.pdf

HTH

Why Garmin isn't adding an option (wearing/not wearing) to auto-correct the reading based on the body temperature so that we may have a more realistic reading of the air's temperature? I believe that some other watches are doing it...

Which watches would those be? I'm intrigued how this would work reliably.

Elevation is based on pressure. Pressure is pressure is pressure. No need for temperature. However, elevation should by based on GPS.

Apart from the other comments above, the temperature sensor in the barometer is there because the pressure sensitive components are also temperature sensitive; the raw reading needs to be compensated for the component temperatures to get a consistent pressure reading.

MrRene. You could just get a Tempe sensor. That's really best thing to do if you want the actual ambient temperature.