His knowledge of astronomical instruments was legendary, especially of optical and electronic devices and of image converters.
He died unexpectedly on 13 March 1984 during a business trip to the Calar Alto Observatory in AlmerĂa, Spain.
In his honour Rudolf Pressberger named his self built observatory in Klosterneuburg-Kierling “Purgathofer-Sternwarte”, and also the asteroid 5341 was named “Purgathofer”.