Link is not available again:
wget http://labs.picotech.com/debian/dists/picoscope/Release.gpg.key
--2016-04-18 09:37:33-- http://labs.picotech.com/debian/dists/picoscope/Release.gpg.key
Resolving labs.picotech.com (labs.picotech.com)... 94.136.50.31
Connecting to labs.picotech.com (labs.picotech.com)|94.136.50.31|:80... failed: Connection refused.