Hi Jon, In chemistry, the boiling point is measured in the vapour phase. When there is liquid present on a thermometer in the vapour, you measure the boiling point of the liquid. When you try to measure the boiling point in the liquid phase you have to cope with problems as 'boiling delay' (i don't know the exact english word for it). Clean liquids tend not to boil at temperatures far above boiling point. A little disturbance causis the start of boiling with a little explosion. (try the experiment with a little bit of water in a clean glass in the microwave....) Boiling the liquid and measuring the vapour temperature above until it stabilises must be easy to automate?! Leo van Loon SBB simpeltronics Netherlands tel +31 (0481) 450034 fax+31 (0481) 450051 mail sbb.simpeltron@tip.nl url http://www.sbb-simpeltronics.nl SBB simpeltronics ontwikkelt technische projecten voor basisschool en basisvorming. SBB simpeltronics develops technical projects for children in primary and secondary education. -----Oorspronkelijk bericht----- Van: PHXSYS Aan: PICLIST@MITVMA.MIT.EDU Datum: zaterdag 21 maart 1998 17:04 Onderwerp: HOW TO MEASURE BOILING POINT >Hello everyone, > >I have a challenge! > >I need some ideas for measuring the boiling point of various fluids. The >specific gravity of one fluid is approx 1.03, very close to water. The >accuracy I am looking for is +/- 3 %. I am looking for creative options, the >simplier the better. > >The boiling points may be as high as 500 degress F. A very small sample of >fluid will be tested 3-10 ml. I believe I will use a small electric heating >probe (hot wire) to quickly raise the temperature. The tesing time should be >between 30-60 seconds. The higher the boiling point the longer the test. > >Can I look for the presence of vapor is a closed system; measure the current >of the probe and watch for reaction at boiling point, measure pressure changes >or pulsations as the fluid boils? > >I would appreciate any code snippits that help. Thanks in advance. > >Jon > >