I am wanting to find out what a 'piladyne' is. This is not the correct
spelling. What I do know is that it is a measuring instrument that is
used in a forest. The context this is in is- "the forest worker's back
condition has revealed he was involved in the constant operation of a
piladyne". Please provide a brief outline on what it does and how it is used.

It is spelled pilodyn.  Check this link: http://www.krsis.dk/pilodyn.htm
 or this one: http://www.proceq-usa.com/products/pilodyn6j.php