Adaptation of the P.E. Model 295 Spectrophotometer to Constant

Adaptation of the P.E. Model 295 Spectrophotometer to Constant-Temperature Measurements We have adapted our Perkin-Elmer Model 295 Spectrophotometer, enabling experiments to be performed that require thermostat control. Considering the widespread use of this particular photometer, a description of the accessory required seems justified as i t is easily made and the cost is neelieible. The ohotometer thus modified can be used in undereraduate classes whose pr.,gramc include labL,ratnr, e x c r r i i t i m kinetic rtudws,or d s r maymesrtivity mtswremrnt.. w c h as rhr dr~nurnrratiwc w p w aciavs descrthed rermrly m r h l * .lor,rnul 1 All rhnt i% rrquirrd tu heacme tu the phm,metrr ir thedrillma oia6-nlm hole in the plasrlc I,aw plate trhnmzhu hirh the inlet tube frum rhr rhermustat will pas>..the h& ireinl: wnrrrrd with r m p m 1 0 the cu\,er hzddrr w I I The c u w t holrlrr isre figure,. the deiign of which a l h w effirienr tlcruof rhr t h r m w ~ barh t Ilquid, i.; mode wth.,ut diii~rultyfrum thin-wall Pyrex ruhme. hvnnvc~nr\vithnlaji-l,l~~u~nr rx. . p&tise; the measurements given enable this accesHory t o fit the photometer a i d permit t h l u s e of 12 X 75-mm Coleman-tvoe .. cuvets. The elass cuvet holder is minted with black matte m i n t excrpt ti,, luo "wlndows"on upposite bides 10 alltlw for hght tmnamlssion. The pwitlm of t h r ~ e \\:nd