( ( Measurement ( of ( ( the luminescence ) ( with ( simple ( laboratory photometers ) ) ) ) ) ) ( ( may ( be ( ( attempted , ) ( though ( ( the light ) ( produced ( is ( at ( ( the ( lower limit ) ) ( of ( sensitivity ( of ( common photometers ) ) ) ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NP (NNP Measurement)) (PP (IN of) (NP (NP (DT the) (NN luminescence)) (PP (IN with) (NP (JJ simple) (NN laboratory) (NNS photometers)))))) (VP (MD may) (VP (VB be) (VP (VBN attempted) (, ,) (SBAR (IN though) (S (NP (DT the) (NN light)) (VP (VBD produced) (SBAR (S (VP (VBZ is) (PP (IN at) (NP (NP (DT the) (JJR lower) (NN limit)) (PP (IN of) (NP (NP (NN sensitivity)) (PP (IN of) (NP (JJ common) (NNS photometers)))))))))))))))) (. .)))
Measurement of the luminescence with simple laboratory photometers may be attempted, though the light produced is at the lower limit of sensitivity of common photometers.
(ROOT (S (NP (NP (NNP Producing) (NN light)) (PP (IN without) (NP (NN heat)))) (VP (VBZ is) (VP (VBN called) (S (ADJP (JJ luminescence))))) (. .)))