Temperature reading Edge 1030 Plus

The temp. sensor inside the unit is affected by solar heating.  I ride a tandem and have two units on the bike, a 1030 Plus for me and a 830 for my wife.  When the sun is directly in front of us, my unit reads 5-10 degrees (F) higher than her unit, as my unit is exposed to the sun and her unit is in the shade.  When the sun is behind us both of our units read identically.  When riding on a climb where the wind speed is low and the unit is directly under full sunlight I've seen the unit report temps. that are 10-15 degrees higher.  The same goes for if you are taking a break and parked your bike.  Lastly, the internal electronics within the unit generate heat and that heat causes a higher reading.  In a nutshell, the temperature reading will be mostly accurate when the airspeed is high and under overcast conditions.  Under a full sun the readings will always be higher than the true ambient temp.  The temp. sensor is not defective in any way.  It's reading the true temperature.  There are just external factors outside of Garmin's control to correct the error.

I believe the effects from solar heating is far greater than any base temp. error.  So even if Garmin would to correct the base temp. error we would still see huge temp. deviations from the true ambient temp.  Also, as I have mentioned earlier the unit itself gives off heat from the internal electronics.  So your 'lab' measurement result should only be accurate if you had taken the measurement immediately after turning on the unit.  If you had waited a few minutes the unit would be warming up and create a false result.  In theory Garmin could attempt to offset the internally generated heat.  Perhaps they are already did but it's still not enough.

Do you know if CIQ is still reading the temp. once every 10min?  I want the real-time reading and I wasn't able to include temp. under HMs DIY due to this quirk.  And also CIQ doesn't pass over Di2 battery status.  So I ended up having two non-CIQ fields on my 1030 Plus in addition to my custom HMs DIY field.  It would be nice to integrate all of the data fields that I want into HMs DIY.  Thanks.

I'm very sorry but I think you are completely missing the point. Any temperature device if exposed to radiated heat will see a temperature elevation as a result of that exposure. That's exactly how they are meant to respond. Any internally generated temperature is so small as to be totally insignificant and a mere fraction of any measured value. The baseline accuracy IS important otherwise you may as well be measuring potatoes, or perhaps I've been misunderstanding these things for the past 40 years in the calibration industry.

As regards CIQ I have no idea but can see no reason why the refresh rate should be any different to the referenced temperature. 

v1sionmaster said:

Any temperature device if exposed to radiated heat will see a temperature elevation as a result of that exposure.

That means: you‘ll never get the „right“ temperature, because the device allways is exposed to sun or/and wind or/and rain…
So what…  (I support Pdlpsher )

v1sionmaster said:

Any internally generated temperature is so small as to be totally insignificant and a mere fraction of any measured value.

I suggest to make a test: at home - „lab conditions“ - turn on your Edge and watch what will happen with temperature. 
Btw: a fully turned on backlight lets the temp raise by about 2 °C. (Edge 1030)

v1sionmaster said:

As regards CIQ I have no idea but can see no reason why the refresh rate should be any different to the referenced temperature. 

Read out temperature for IQ apps is a backgroung process. These events can not occur more often than every 5 minutes.

I've only just started using CIQ in the last few weeks and I'm happy to defer to anyone who knows more about that! :-) :-) Strange because I've watched the temperature change on the field in real-time in 0.1 F increments. I didn't KNOW what the background refresh is so I can only go on what I see in front of me.

I have never said that the radiated temperature doesn't mask the actual temperature measured in shadow. 

Are you certain that what you observe is related to the internal temperature warming up of the device? There are circuits in many temperature measuring devices that need a short while to stabilise - particularly those using thermocouples and resistance thermometers. I've just used a surface temperature probe (a Comark certified to NPL Standards) to measure the temperature of the Edge and I detect no temperature rise in 5 minutes. My backlight is set at 30% and I wonder how many users operate at 100%  beyond the standard timeout period.

Garmin units used to have internal temperature sensors that are used for calibration of the unit's oscillator frequency which is essential for the proper operation of the GPS. That contributes to the rather slow response (thermal mass).

There are soooooooo many threads in these forums about the temperature accuracy of the different edge devices. My previous Edge 1000 was always within 1 to 2 degrees F in the lab. Before that my 810 was a little further adrift at 2 to 3 F.

The times when the device is stationary in direct sunlight will most definitely result in a greenhouse type effect and the temperature will soar. Once you start riding again the temp gradually comes down to the surrounding air temperature value. Just as a thermometer does. It is under those riding conditions that the temperature will most accurately reflect the true temperature value. At that point the value ought to be able to be within much closer tolerances than many people observe and report widely here. The error on my 1030 plus is +6f and consistent in that terror compared to the Edge 1000's of devices on the bikes of 3 of my riding partners (all of which are within 1 F of each other in the same location on the same ride when moving and when later reviewed I the trends on Strava or Garmin Connect.

The significance of that error is important (or not)  to different users, none of whom can be criticised for expecting better from their devices when it has quite clearly been possible before. The Edge 1030 received a temperature correction so it was deemed necessary by Garmin. Garmin have acknowledged the error on the 1030 Plus and will hopefully resolve it. In the meantime the Edge 1040 is due out this month - my local bike shop has them on order already.

Accuracy is important to me - it's as simple as that :-) It is to many others too as witnessed by the number of posts on the subject. End.....

I did a test with all my Edges (I keep them all!  )

I tried to have clean "labor" conditions:
Went to the basement - no sun, no wind, no rain   - constant room temperature.

All Edge devices rest for 2 hours in that place - turned off - to bring all of them to the room-temperature.

Then turned on all devices with no backlight for the first 20 minutes.

After 20 minutes I switched on backlight to full on all devices.

Result:

Note: Edge 1030 Plus is the stablest, but about 1,5 to 2,0 °C too high.

The older models are strongly influenced by the backlight. Only the Edge 1030 PLUS might have an internal correction here.

Great collection there! I've had the 800, 810, 1000 and 1030 plus :-) Your findings with the 1030 plus certainly demonstrates that an error occurs, and I doubt any Garmin temperature sensor will be batch selected for accuracy so different devices MAY show different errors ;-)

I found that when tested through the range 40F to 80F (4.4F to 26.6 C) that the Garmin showed +5F to +6F (2.7C to 2.3C) high.

If they do have any internal correction, that would lean towards the use of a Thermocouple (CJC error). Resistance thermometers would have to have a software fix to create an offset based on know error.  A class B RTD should have an accuracy of +/- 0.3 C. The overall system accuracy is a compound of the uncertainty of the probe, the uncertainty of the measuring unit and the uncertainty of the calibration.  I would NEVER expect to have anything better than +/- 3F.

The 1030 data is very revealing as that unit had a temperature correction update from Garmin - it looks as though they got pretty close :-)

You have certainly gone to a lot of trouble with this! Thank you. For my part, I could only make direct checks between the 1030+ and certified reference thermometers. The error was linear through the range with less than 0.5 F shift at any intermediate point. So that should allow an offset to be created should Garmin decide to do anything. I'm told that they will but without a timescale. Let's see what the Edge1040 brings ;-)

My other main cases with Garmin are in relation to the 3D map display and the Auto Sleep.

Thanks for that test, very interesting as I have had all of those garmin devices myself and have to say the one I found showing the correct temperature outdoors and indoors was the 1030 the plus is always +4/5 of the actual temperature.

thanks again

Muriel

I believe that somewhere in the 1030's history there was a temperature correction rolled out - shame they can't do it for the 1030 plus MAYBE it will come in the second part of the 6.3 rollout - but maybe not ;-)