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Elevation consistently inaccurate (reading too low)

I'm having issues with the Instinct reading lower elevation than it should, which results in considerably lower elevation gains than what you should be seeing. One might be tempted to blame this on sweat, poor weather conditions and what not, but that's actually not the case. I'm noticing this on a very short ride (roughly 11km). Start and finish elevation are typically within 5m of each other (which is IMHO fairly accurate). I've had three different devices prior to this one (cycling computers)

After looking more closely at the graphs, I've noticed that the Instinct just plain out ignores certain elevation gains, and instead chooses to think I'm riding a flat profile. It does so very consistently and given that the starting and ending point read the same elevation, I'm inclined to believe this is a sofware issue. Naturally, the watch mode is set to altimeter.

So my question is whether this is a known issue and whether I can expect a fix. Difference of 40m in 11km is pretty big in my opinion.

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0 7343754 over 4 years ago in reply to 7343754

Warning to those considering buying an instinct. If elevation is important to you then do not buy this watch

0 awsum140 over 4 years ago

Does anyone use the Instinct for skydiving? Given the problems with altitude/barometer I don't think it would be a very good idea. Mine shows me hiking/walking at -1640 feet. Guess I'm at the bottom of a coal mine. I've washed and soaked it, in fact it gets rinsed daily at least once a day, with no real effect. Currently on software version 10.0 with no change with this problem since I got the watch in March. Looking at some of the solutions mentioned, maybe try dancing with an eggplant on your head, under the light of a full moon while it's raining would work better. Very disappointed with the Instinct given Garmins' reputation.

0 darnich over 4 years ago in reply to awsum140

It is always a good thing to keep the sensor holes clean, however after rinsing the watch or washing your hands (especially now during the pandemic) make sure to get rid of the excess water that may be trapped inside. Each time after I wash my hands I take off the watch and gently slam it on my leg with the holes facing down to force any excess water out. I do have to calibrate the altimeter a few times each day but after the last update to v10 it is way more accurate.

0 trux over 4 years ago in reply to awsum140

awsum140 said:
Does anyone use the Instinct for skydiving?

I would not use any watch (or any altimeter) that is not certified specifically for skydiving, if your life depends on it. Regardless of the brand. Instinct's altimeter is very sensitive on external influences like dirt, moist, sweat, wind gusts, air flow due to fast descents (causing either direct increase of pressure, or oppositely underpressure due to Bernoulli's effect). So use it for logging your skydives, but do not rely on it for opening your shute!

0 awsum140 over 4 years ago in reply to darnich

Already do that. Somewhere, someone said to let it air dry. Given the hole size and potential air circulation versus the amount of water that can be trapped, that can lead to a few days of air drying. Just a poor design IMHO. The sensor belongs on the side, away from the wrist, to be effective. Possibly the software/firmware need adjustments to decide what constitutes a flight of stairs or change in elevation.

0 4906382 over 4 years ago in reply to awsum140

It's surprising that although it's a flawed design, Garmin decided to keep the exact same design on the new 400$ Instinct Solar

0 awsum140 over 4 years ago

I contacted Garmin and they determined there was a problem with the sensor, so I did an exchange of the watch. I had high hopes after a short walk, a mile, in the basement and the altitude showed properly. I finally got outside for a longer walk today and while it is better it still is pretty far off. Due to the CCP Virus I walk in out yard, we have over an acre, which has, at most, a six foot elevation change. It shows that I ascended eight flights of stairs but descended 36 flights. There are no stairs, at all, in the back yard where I walk. The altitude shows a 288 foot differential, from -167 feet to +121 feet. I don't skydive but if I did I sure as heck wouldn't rely on the Instinct for guidance on the way down. Garmin advertises that feature which would lead one to think that it is fairly accurate when determining altitude. In reality, it isn't even close. The inaccuracies with altitude make any of the readings of the watch fairly questionable in my mind since that shows problems either with hardware or software/firmware. I had high expectations given Garmin's reputation, but instead have deep disappointment.

0 oldschoolczar over 4 years ago

I really want to love this watch, but as a climber/hiker the elevation/ascent readings are what I'm most interested in. As a devout Garmin GPS watch fan, I'm a bit disappointed in the accuracy of the altimeter on this watch. I did a hike with 2650 vertical feet last weekend. At the end, it said I climbed 3350 vertical feet. It's off by more than 25%. That's totally unacceptable. At one point as I was climbing switchbacks I looked at my watch to see how far I'd climbed and it said 720 vertical feet. I looked at it again literally 20 seconds later as I've been keeping an eye on it and it read 900 vertical feet of ascent. I had probably climbed 10' at most to 730 vertical feet. It jumped 180 vertical feet in 20 seconds. I can't help but think this is due to sweat. It probably entered the sensor when I moved my arm/wrist up to look at the watch. FYI I had the barometer in 'altimeter mode". However, I often go on ~8-hr hikes/climbs so I think at that length I'm better oft using "Auto" mode since the weather can change over that length of time.

I estimated my vertical at 2650' from other information and topo maps. When I come back and use the Garmin Connect elevation correction, I'm within 50' of that for ascent/descent. It's almost perfect.

As mentioned above, I think Garmin should provide the option when tracking elevation to use the altimeter or to use GPS data. I honestly can't believe they haven't implemented this simple change! Should take a programmer a day to fix the code. I hiked for 3-4 years with my VivoActive HR and while GPS elevation information is not as accurate as horizontal, I find that it's MUCH better than what I get with the Instinct altimeter. I was always within ~5% of the published ascent values for mountains in my area. So why not offer the option to get +/- 5% accuracy rather than 25-30% accuracy. C'mon Garmin! You'll appease half of these complaints if you just did that simple firmware fix. Give people the option. PS Also add battery percentage instead of days... percentage is what data/measurement nerds (who buy these devices) want to see!

Lastly - how do you calibrate the barometer... not the altimeter, but the barometer!? It asks for elevation and "sea level barometric pressure". I put in my elevation at 5400ft asl, then I get a reading from my local weather station, and calculate the corresponding sea level pressure in my area from equations/calculators online and enter that for the "sea level pressure". Should be all good right? However, I go and look at my barometer reading and it's showing exactly what I just typed in for "sea level pressure". Why isn't it accounting for my altitude of 5400ft asl? I'm typically 2 in HG less than sea level pressure. The calibration scheme for the barometer is completely jacked up and needs some clarification. I have no idea of this thing is calibrated correctly. Maybe it doesn't mean "sea level pressure", but "local pressure".

0 oldschoolczar over 4 years ago in reply to oldschoolczar

I've noticed from review of the elevation profiles on all of my recent activities, that almost without fail about 15-20 mins into an activity I get an elevation drop of about 200'... like a straight drop of 200' +/- over 3-5 seconds. I can't only conclude that this is about when I start to get sweaty and this is almost entirely a design flaw / hardware issue. For someone who uses the altimeter as a navigation aid and needs to rely on it in the field, this is a dealbreaker for me. I'm going to see if Garmin will swap this out for another watch or if not, if one of these 3d-printed pieces will fix the problem.

0 awsum140 over 4 years ago in reply to oldschoolczar

I returned my original Instinct and got a replacement. While the GPS function works properly in the replacement, the barometer/altimeter still report false and misleading information. For example my morning walk on a relatively flat area shows I ascended 5 flights and descended 20 flights. The "stats" show an altitude change from -49ft to 203ft in an area that is about 100ft above sea level. Additionally the compass will not calibrate and is wildly off from day to day, generally indicating wet heading no matter which way it is facing. I've given up on the thought of anything close to accuracy from the Instinct.