On a rare occasion, we get someone saying their wind speed is not registering, but the impeller is spinning, so I thought I'd address this...

If wind speed isn’t displaying on the unit there’s really only 3 possibilities: 

  1. the magnet in the impeller isn’t strong enough (anymore – sometimes they fail after several years), 
  2. the copper inductive coil (receiving sensor) on the PCB has broken, or there is some other electronic failure (sometimes temporary) in the unit.  (This would mean it needs to be sent to back to Nielsen Kellerman)
  3. The unit needs a hard reset: for this – remove the battery (or batteries if Kestrel 4000 series), hold the power button for approximately 30 seconds to discharge any capacitors on the circuit board, then reinsert the battery/batteries and proceed normally.

One of the easiest ways to test for the first 2 is to replace the impeller – if you do and it works again, it was likely the first problem, if not, it was the 2nd problem.   You can simply replace the impeller yourself, by pushing it out with your thumbs.

If you don't want to invest in a new impeller unless you know that’s the issue, you can test it by holding the Kestrel up to an iron core ac/dc adapter which is actually powering something (shown in the picture attached see below).  I used my Mac power source and worked fine, needs to be iron core ac/dc, or it won't work.