Hodgkinson, JaneJohnson, MarkDakin, John P.2012-12-102012-12-101998-01-01Jane Hodgkinson, Mark Johnson and John P. Dakin. Photothermal detection of trace compounds in water, using the deflection of a water meniscus. Measurement Science and Technology, 1998, Vol. 9 (8), pp 1316-13230957-0233http://dx.doi.org/http://dx.doi.org./10.1088/0957-0233/9/8/026http://dspace.lib.cranfield.ac.uk/handle/1826/4301Anovelphotothermaldetectorisdescribed,basedonaclosedcellsuitableforusewithlow-frequencymodulatedcontinuous-wavelightsources.Photothermalexpansioninaqueoussamplescausedthedeflectionofawatermeniscusheldacrossa200m-radiuspinhole.Displacementofthewatermeniscuswasmeasuredusingfibreopticinterferometry.Amercurydischargelamp(254nm)andalaserdiode(678nm)wereusedtodetecttoabsorptionby2ppbanthraceneand0.5ppmpotassiumpermanganateinaqueoussolution,respectively.Thetechniquewasusedtodetectdifferencesbetweenabsorptioncoefficientsinaqueoussolutionsdowntoapproximately20%ofthebackgroundabsorptionofthewateritself.Photothermal detection of trace compounds in water, using the deflection of a water meniscusArticle