1) Measuring instrument 
A hedonometer or hedonimeter is a device used to gauge happiness or pleasure. Conceived of at least as early as 1880, the term was used in 1881 by the economist Francis Ysidro Edgeworth to describe `an ideally perfect instrument, a psychophysical machine, continually registering the height of pleasure experienced by an individual.` More recently.....
hedonometer Used humorously, an apparatus for measuring pleasure.