Length doesn't show zero with no fiber attached - Fiber QuickMap™

Without a fiber connected to the Fiber QuickMap™, the length reading should be 0 ft or 0 m. It's very unlikely, but it may read 1 ft or 1 m. You can "calibrate" it to 0 ft or 0 m.

Let's make sure you are the right screen first.
Press TEST so that the length reading is reported.
It should of course show 0 but in this case it shows 1. 

Press and hold down  for 5 seconds to see 0CAL appear.
Press and hold down the  for one second to start the calibration process.  




When you see done, press TEST to verify that it now shows 0 ft or 0 m when no fiber is attached.