[Shop-talk] IR temperature meter

[Elton E. (Tony) Clark]

*I have a little IR temperature meter which I use around the shop checking
AC in and out temps, motor temps, etc . . one day I was outside checking the
wall temp to see how my insulation was working, it was about 50 degrees
ambient and . . . I aimed the meter at the clear blue sky:  It read minus 15
degrees!!!!!!       Is it really measuring something?  Is that a default?
HELP!!!!!*

*Tony*