Will this keep track of cumulative verticle decent for a week or so?
JAMES R Hi Daren,
This altimeter keeps track of altitude by use of barometric pressure. It will be accurate only if the altitude is calibrated daily to a known altitude like a USGS marker. Weather changes over a week of time, without calibration, will result in error of 200 feet or so. It keeps track of maximum altitude and change of altutude by use of a bar graph display. Each time you reset the altitude thru calibration the graph erases and starts fresh. The answer to your question is yes, it will keep track over long periods of time, but the longer you go without reseting the less accurate it is.