英国mickleBK干燥记录器TheBK6andBK10Recordershaveindependentlyoperatingtracksallowingteststobemadeatdifferentstarttimes. Pairsoftracksoperateatthesamespeed,andawiderangeoftraveltimesareavailable.Travel timesof6,12,24and48hoursareallconsideredasstandard. Atimescaleon the front coverisgraduatedtosuit the instrument s drying time ranges. Eachpairoftrackshasitsownindividual operatingswitch.BK10TheRecordersdefinestagesinthedryingprocessas:-Stage1 Apearshapedimpressioncorrespondingtothetimetakenforevaporationofthesolvent.Stage2 Thecuttingofacontinuoustrack,correspondingtoasol-geltransition.Stage3 Aninterruptedtrackcorrespondingtothesurface-drytime.Stage4 Theneedlenolongerpenetratesthefilm,correspondingtothefinaldryingtime. Brassweights,eachweighing5grams, maybeusedtoapplygreater pressureon theneedles and thusrecordthethrough-drying propertiesof alkyds,varnishesand paints. The BKDrying Recorders willgiveusefulinformationaboutthegelationtimesof many twocomponentsurfacecoatingmaterials,andaboutthepropertiesofsuchfilms.