( ( ( Interpretation Calibration ) ( of ( particle concentration ) ) ) ( ( ( is necessary ) ( because ( ( ( the number ) ( of ( particles detected ) ) ) ( ( depends ( on ( the ( volume ( flow rate ) ) ) ) ) ( through ( ( the ( sensing region ) ) ( defined ( by ( ( the intersection ) ( of ( the ( two ( IR ( laser beams ) ) ) ) ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NP (NNP Interpretation) (NNP Calibration)) (PP (IN of) (NP (NN particle) (NN concentration)))) (VP (VBZ is) (ADJP (JJ necessary)) (SBAR (IN because) (S (NP (NP (DT the) (NN number)) (PP (IN of) (NP (NP (NNS particles)) (VP (VBN detected))))) (VP (VBZ depends) (PP (IN on) (NP (DT the) (NN volume) (NN flow) (NN rate))) (PP (IN through) (NP (NP (DT the) (JJ sensing) (NN region)) (VP (VBN defined) (PP (IN by) (NP (NP (DT the) (NN intersection)) (PP (IN of) (NP (DT the) (CD two) (NNP IR) (NN laser) (NNS beams)))))))))))) (. .)))
Interpretation Calibration of particle concentration is necessary because the number of particles detected depends on the volume flow rate through the sensing region defined by the intersection of the two IR laser beams.
(ROOT (S (NP (NP (DT The) (NN number)) (PP (IN of) (NP (NP (NNS particles)) (PP (IN of) (NP (NP (DT a) (NN substance)) (PP (IN in) (NP (DT a) (VBN given) (NN volume)))))))) (VP (VBZ is) (VP (VBN known) (PP (IN as) (NP (DT the) (NN concentration))))) (. .)))