Compass calibration scale

[vashon100]

Did a compass calibration today. Previously there were no related issues in 70 flights, but compass sensor meter showed long yellow bars for both compasses. After the calibration (done in an appropriate area), both compasses now show green. However, the greens are really short bars.

I'm guessing this is indicating the reading is just barely in the green region. It sounds like the very long yellow bars were indicating meter was just below the green level (ie high yellow). Is that the way to interpret?

 

[Flawless]

The bars show the current level of interference. The closer to zero, the better.

Just be aware that if you calibrated while the bars were yellow, you've just told the compasses that whatever interference was present is "normal".

If you move away from whatever was causing the interference (doesn't have to be magnetic, just ferrous metal or electromagnetic) then the calibration is going to be wrong again.

You need to ensure that you're in a location as free from interference as possible before calibrating.

 

[vashon100]

The bars show the current level of interference. The closer to zero, the better......

Now, I'm a little confused. What does the color mean if a long green bar would be bad rather than "excellent"?

Is the color associated with the health of the compass which is different than the bar length (ie number) which is a measure of interference?

 

[Keule]

It is better to have a short green bar than a long green bar. (Green is excellent) The more the bar goes to the right, the color changes to yellow or even red. (Red = Bad/Poor)

In the image below, compass1 indicates to be better than compass 2.

 

[vashon100]

Ok, got it. Thanks to both of you for the info.

When looking at this: DJI Mavic Compass Calibration Guide - Mavic Help .......it says to do a calibration "when compass interference values are out of whack"

Can someone give me an example of what that means? Is it when a person thinks there are no effects around to give the reading it does? Like a situation where everywhere you fly you get long bars.

 

[Keule]

Can someone give me an example of what that means?

This:

 

[vashon100]

Ha! Thought it was referring to a more subtle scenario.

 

[locoman]

Good to know that short line is better. Mine have always been on the green short side. Thought that meant an ok, but weak signal, though I have never had a compass issue. Also, when I start up the MP, 90% of the time I get the screen requesting to calibrate the compass, which I will do, even if it is the same location I launched from the previous flight.

 

[msinger]

When looking at this: DJI Mavic Compass Calibration Guide - Mavic Help .......it says to do a calibration "when compass interference values are out of whack"

Can someone give me an example of what that means?

It means you should calibrate the compass if the bars are not green and you know your Mavic is definitely not near a magnetic metal source.

 

[vashon100]

It means you should calibrate the compass if the bars are not green and you know your Mavic is definitely not near a magnetic metal source.

Good to hear, that was my situation.

 

[vashon100]

...... Also, when I start up the MP, 90% of the time I get the screen requesting to calibrate the compass, which I will do, even if it is the same location I launched from the previous flight.

Does it present itself by the word calibrate in a box? If so, that is just the button to initiate a calibration, rather than a need for calibration.

 

[msinger]

Does it present itself by the word calibrate in a box? If so, that is just the button to initiate a calibration, rather than a need for calibration.

Good point.

FYI, here's the "Calibrate" button you're referring to:

 

[Turn11]

If you move away from whatever was causing the interference (doesn't have to be magnetic, just ferrous metal or electromagnetic) then the calibration is going to be wrong again.

I understand there is a difference between an underground electrical cable for an outlet and an underground cable that supplies football field flood lights. The last was an extreme, I understand that.

How close to interference before it starts to be a problem. General rule of thumb, I know it is not an exact science.

 

[Cut.Aussie]

Assuming the electrical cable is carry AC power then it’s not an issue.

The issue is with something like the DC cable between the north and south islands of New Zealand that even screws up ships compasses.