Dan Marotta wrote on 9/18/2017 10:01 AM:
Your vario sink rate is an indicated rate, as is the airspeed indicator, so your
calculated glide ratio, /_in the airmass_/ should be a simple calculation. Having
said that, the air is too dynamic to care what your instantaneous glide ratio is
and, like thermals, and investments, past performance is no guarantee of future
performance. It's all "golly, gee-whiz" stuff at the end of the day.

Unless the vario manual declares the calibration is in "indicated" units, I've
always assumed it's calibrated in true rate-of-climb. I recall the old mechanical
(and maybe the thermistor flow sensor varios), flow driven vane-type varios did
read "indicated", but for decades, varios have used pressure sensors and I think
they are calibrated in "actual rate of climb".

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
- "A Guide to Self-Launching Sailplane Operation"
https://sites.google.com/site/motorg...ad-the-guide-1
- "Transponders in Sailplanes - Dec 2014a" also ADS-B, PCAS, Flarm

http://soaringsafety.org/prevention/...anes-2014A.pdf