Altitude Calibration Question For 76cs

[+dhbaird]

Today I located 3 different benchmarks. While I was at the first of them I calibrated the altitude sensor on my 76cs for the height that was in the record books for that benchmark. I checked the altitude at the next 2 and it was within a foot or 2. Thought that was pretty good.

 

My question is how long does that calibration last. Did I lose it when I turned off the unit when I was done?

[rickertk]

Today I located 3 different benchmarks. While I was at the first of them I calibrated the altitude sensor on my 76cs for the height that was in the record books for that benchmark. I checked the altitude at the next 2 and it was within a foot or 2. Thought that was pretty good.

 

My question is how long does that calibration last. Did I lose it when I turned off the unit when I was done?

 

Probably not. However, it won't last particularly long. Barometric altimeters tend to drift with changes in the air pressure as weather systems come and go. If the 76cs is anything like the 60cs and VistaC (which I have), under the Setup>Altimeter menu, you have the chance to turn Auto Calibration on, which tries to regularly autocalibrate to GPS altitude to compensate for air pressure changes. Calibrating to a benchmark is a good way to measure the altitude of another location with fairly high accuracy, soon afterwards. If you measure the altitude of, say, your home, you can regularly calibrate to a reasonably well determined position.

Keith