On Tuesday, August 11, 2020 at 12:01:37 AM UTC-4, krasw wrote:
There seems to be a misconception about time constant of variometer. Many (all?) think that 2 sec time constant means that it takes 2 seconds after hitting thermal for variometer to show any lift. This is not true. Time constant means that within that time variometer needle reaches 100% of the pressure change signal. That does not mean that variometer needle does not start to show at least something (needle starts to rise) before that 2 secs.

What is the advantage of that 2 sec time constant, i.e. taking 2 seconds to reach 100% of the pressure change? Is the advantage that setting the time constant to a lower value (say, 1 sec or a half sec) means that the vario NEVER reaches 100% of the pressure change? i.e. you never get to know how good the thermal really is?

Ben Ethridge