Altimeter issues. Reset/Calibration possible?

[Stu_Barnes]

Well we have a potential winner here. lowest reading gets a free mug and t shirt.

It's official competition time.

Entries close on last day of Feb.

Ok so who won??

 

[Stu_Barnes]

Tough crowd, I’ll dig through 6 pages and find out who won the coveted Grenadier “lowest of the low” award

 

[Jeffrey]

I enjoyed the humor of this contest, but more so I’m pissed off that I paid good money for this piece of crap accessory that doesn’t work.

 

[Jackattack13]

I live at sea level in Carlsbad, CA and am regularly -80 to -110 ft below sea level. I hate that it cheapens the vehicle. Like people get in and say, ha! Looks like we are underwater. Should be a feature to quickly re-calibrate it. I would of saved the money if I knew it was going to be a decorative piece.

 

[Krabby]

 

[Tom109]

I’m in So. FL and having same issue: reads as being around -80ft, which is absurd. A lot of chatter on thus thread about the altimeter being barometric presure-based…but that strikes me as weird and incorrect. Does anyone on this forum have reference or proof that it’s barometric?

Driving through the Baltimore Tunnel yesterday, the altimeter showed -100ft while the GPS teltale
At the top of the screen showed two hash marks. It is definitely barometric.

 

[Zimm]

I’ve yet to be above water.

View attachment 7843648

Better watch out. After three years the IRS may declare you a hobby, and you'll lose your write offs.

 

[Zimm]

Tough crowd, I’ll dig through 6 pages and find out who won the coveted Grenadier “lowest of the low” award

Is this for elevation or worst commentary?

 

[Zimm]

Some people are a riot. Altimeters in vehicles are relative to conditions and are utilized for measuring CHANGES. My garmin NEVER matches my USGS maps in the woods. EVER. It was never intended as anything more than cool bling. Like switches on the roof.

 

[Zimm]

The fact the IG has altitude I think it is a fair question to ask if it can be calibrated. It doesn't seem that any of those who replied, answered that question. Who cares what the margin of error is for an airplane. I too live at sea level and feet matter. Also as a cyclist, elevation on a ride is important. Especially when you are riding in the mountains. It would be good to know you are getting accurate numbers. I am sure eventually someone will figure out if the altimeter can be calibrated. When they do, I hope my search to this question will also be answered.

I'm confused and curious. What good is an altimeter in a car going to do you for recording total elevation completed on a ride?

And being at sea level, to achieve 1 foot accuracy you would have to re calibrate it 10 times a day, meaning you would need to carry detailed maps with you anyway.

 

[Tom109]

@Zimm is right, barometric altitude is just a reference at best. The unit in the Gren is novelty, but it makes me happy and I like it.

 

[Zimm]

@Zimm is right, barometric altitude is just a reference at best. The unit in the Gren is novelty, but it makes me happy and I like it.

Oh yea. It's like my automatic mechanical watch. For accurate time, I look at my phone, but my watches give me warm fuzzies.

 

[Stu_Barnes]

The altimeter is linked into the GPS system of the Grenadier. Lose GPS and it goes out. —— on both the infotainment and the compass.

 

[Zimm]

I read this the other day on Aviation. It may help people understand the method of use of altimeters for people that don't really connect as to why it "off".
------------------------------------------------------------------------------
Now in aircraft, each of these quantities has different use:

• The geometric altitude from GPS is, together with a topographic map, used in EGPWS to alert pilots that they are flying too low. Compared to older GPWS that only used the radio altimeter this has the advantage that warning can be given when the aircraft is high enough above ground directly below, but approaching higher ground where it won't be.
  GPS is good for this, because when it works, it always gives the geometric altitude without need for setting that might be incorrect. However, it is a new technology that not all aircraft have and it might be unavailable for external reasons (that can't be mitigated by adding redundancy).
• The barometric altimeter is used for aircraft separation. Here, the exact altitude does not matter, what is important is whether the aircraft are at the same altitude or not. Barometric altimeter is excellent for this, because it is old technology, so all aircraft since the early days have it, and it is simple technology, so it is reliable.
  Above certain altitude (the ‘transition altitude’, 18,000 ft in the USA, but varies in other parts of the world), all aircraft have the altimeter set to the standard value of 29.92 inHg/1013 hPa. This high, there is no concern of separation from terrain, so everybody just uses the same setting to keep things simpler and errors less likely. The pressure altitude can easily differ from the geometric by couple thousand feet, but nobody cares, because it is only important to know whether the other plane is above, below or same altitude and this serves that purpose well.
  Below transition altitude, the altimeter setting from nearest airport is used, so the altimeter reading better approximates the geometric altitude for purpose of separation from terrain. However, the altitudes still only match at the altitude of the airport from which the setting is. Above (and below) the error increases. In cold weather, you can easily be 10% lower height (above ground) than the altimeter says. This is simply handled by adding sufficient margins to the published minimum altitudes.
• The height measured by radio altimeter is used in the GPWS and EGPWS systems to warn pilot of flying too close to the ground and for announcing the height during final approach so the pilot can better judge the landing without having to look at the instrument. However, due to terrain irregularities, radio height is not much use outside these two specific cases. Also, radio altimeters usually only indicate up to 1,500 ft–2,500 ft if installed at all (all airliners have it, but most GA planes don't).

 

[Zimm]

The altimeter is linked into the GPS system of the Grenadier. Lose GPS and it goes out. —— on both the infotainment and the compass.

Mmmm... Is this a barometric or GPS altimeter?

 

[Jean Mercier]

Mmmm... Is this a barometric or GPS altimeter?

I thought it was barometric, because at exactly the same places I am sometimes above, and sometimes below sea level!

 

[Zimm]

I thought it was barometric, because at exactly the same places I am sometimes above, and sometimes below sea level!

Me too. GPS isn't spot on either, but stu's comment about GPS and it appearing all the comments are 30m low everywhere, I got to wondering if it isn't a programming issue with the unit.

 

[Stu_Barnes]

it could be a wickedly over complicated combination unit.

 

[DaveB]

Oh yea. It's like my automatic mechanical watch. For accurate time, I look at my phone, but my watches give me warm fuzzies.

I have an Apple watch Ultra and the screen face is an analogue watch.
I prefer the look of an analogue dial and I don't need to know the time to the minute.

 

[Zimm]

it could be a wickedly over complicated combination unit.

Wasn't that 300 bucks? I'd be surprised for 300 bucks considering the markup on the smokers pack and premium sound. I would think there would be an autocalibrate function on it too.