( ( G Geiger ) ( ( ( counter instrument ) ( for ( measuring ( ( the intensity ) ( of radiation ) ) ) ) ) . ) )
(ROOT (S (NP (NNP G) (NNP Geiger)) (VP (VBP counter) (NP (NN instrument)) (PP (IN for) (S (VP (VBG measuring) (NP (NP (DT the) (NN intensity)) (PP (IN of) (NP (NN radiation)))))))) (. .)))
G Geiger counter instrument for measuring the intensity of radiation.
(ROOT (S (NP (NP (DT The) (`` `) (NN counting) ('' ') (NN instrument)) (NP (NN geiger) (NN counter))) (VP (VBZ is) (VP (VBN used) (S (VP (TO to) (VP (VB measure) (NP (NN radioactivity))))))) (. .)))