base689 0 #26 November 11, 2003 > What you call sensitivity is really the resolution. Yes yes yes, you are right. I did not want to write down an essay on electronic measurements. > Now you have an altimeter showing the altitude typically +- the altitude resolution. Yes, I agree. > The accuracy is the maximum deviation between the true altitude and the altitude measured by your altimeter. Yes, I agree (it is more or less what I wrote...). > The accuracy is worse than the resolution. Yes, in the sense that accuracy is a greater number than resolution. > What is important for the user is the resolution (what is the smallest altitude change I can measure) Yes, I agree. But resolution is important only to a limited extent (=alti watch feels if you climb 1 m higher, but you are NOT sure to be at an actual "readout"+-1 m!!!!). > and the accuracy (How much can I trust the displayed altitude). Yes, I agree again. But my post was meant to alert our friends that an alti watch that has got a resolution of 1 m is NOT "precise" within 1 m, i.e.: an alti watch with 1 m resolution can be as accurate (=precise) as another alti watch whose resolution is 5 m. I.e. again: having a 1 m resolution alti watch does NOT mean that you are "precise" within 1 m. My actual experience with my 5 m resolution Suunto is that within 100 m of range my Advizor is accurate within +-5 m (same as resolution), having once (for example) read 80 m of height of a brdige (zeroed on top, went down the bridge and read -80m) that months later I measured with a laser rangefinder to be 85 m actual height. My message wanting to be: my friends skydivers/BASE jumper, be careful: an alti watch with 1 m resolution does NOT mean that you get readouts accurate within +- 1m!!!!!!!!!!! Reasonable accuracy for those sort of instrument is about 5 m!!!! please, don't come and tell me: "That object is 81 m high!!! I swear!!!". A counter proof showing the "5m accuracy" story can be the one of taking measurement with the "1 m resolution" wonder of a certain object on 10 different days, with zeroing just at the top of the object (or at the bottom) at the very beginning of each measurement. Just my 0.02€Stay safe out there Blue Skies and Soft Walls BASE #689 - base_689AT_NO_123_SPAMyahoo.com Quote Share this post Link to post Share on other sites
Jonsmann 0 #27 November 11, 2003 Sorry pal, not trying to beat on you! You happened to stumble onto one of my "issues". I used to train engineers for a living, and most of my students didn't understand the concepts of sensitivity, resolution etc. So I made it a habit to give a lecture at any given opportunity! - Jacques Quote Share this post Link to post Share on other sites
base689 0 #28 November 11, 2003 > Sorry pal, not trying to beat on you! No worries, mate!!!!!!! Stay safe out there Blue Skies and Soft Walls BASE #689 - base_689AT_NO_123_SPAMyahoo.com Quote Share this post Link to post Share on other sites
