Settings Submenu .............................................................................. 30 
Language ..................................................................................... 30 
Units ................................................................................................ 31 
Time & Date ................................................................................. 31 
Pressure ........................................................................................ 33 
Reminder ...................................................................................... 34 
Backlight ...................................................................................... 35 
Battery .......................................................................................... 35 
Power off ..................................................................................... 36 
Navigation ................................................................................... 36 
Rounding ...................................................................................... 36 
Factory Settings ....................................................................... 37 
How to Measure ................................................................................... 38 
Application Examples ....................................................................... 40 
Maintenance.......................................................................................... 44 
Cleaning ........................................................................................ 44 
Changing the Filter .................................................................. 45 
Changing the Probe ................................................................ 46 
Calibration ..............................................................................................47 
Calibrating the HM40 Using HMK15 ................................. 48 
Accessories and Parts ....................................................................... 53 
Filters ............................................................................................. 54 
Chargers and Batteries .......................................................... 55 
Belt Clips and Battery Covers ............................................. 55 
Technical Data ......................................................................................56 
Relative Humidity and Temperature Measurement 
Performance ............................................................................... 56
 
Mechanical ................................................................................... 58