Liquid Handling

ThermometersThermometerBRAND thermometers – premium instruments for measuringtemperature.These high quality thermometers are manufactured in a singlecasting for a long service life. The dark amber stain is integratedwith the glass surface, and is particularly resistant to chemical andphysical corrosion.Note!At temperatures above 150 °C, the thermometer mustbe carefully preheated approximately to the temperatureto be measured before immersion in the fluid.Temperature and DensityGOLDBRANDPrecision thermometers,suitable for official certificationor officially certified (theofficial certificate is valid for15 years).The accuracy is within thePTB* approved error limits.SILBERBRANDGeneral-purpose thermometersfor routine applications.The accuracy remains withintwice the PTB* approved errorlimits.* PTB (Physikalisch-TechnischeBundesanstalt): German FederalInstitute of Physics and MetrologySolid-stem thermometer,yellow coatedThe vivid yellow coating on theback of these thermometersclearly contrasts the mercurycolumn and graduations.Enclosed-scalethermometerBRAND also carries thermometerswith opal glass scales.Error limits forthermometersThe following error limits areaccording to "Eichordnung EO14-1", the German FederalWeights and Measures Regulations.For thermometers calibratedfor total immersion containingnon-wetting thermometricliquid (e.g., mercury andmercury-thallium alloy) and forthermometers containing wettingthermometric liquid (e.g.,toluene, pentane and petroleum).Official error limits for thermometers containingnon-wetting thermometric liquids, for the subdivisions:Temperature rangefrom °C/to °C0.05 °C 0.1 °C 0.2 °C 0,5 °C 1 °C 2 °C 5 °C-58 / -10 – ± 0.3 ± 0.4 ± 0.5 ± 1 ± 2 ± 5-10 / 110 ± 0.1 ± 0.2 ± 0.3 ± 0.5 ± 1 ± 2 ± 5110 / 210 – – ± 0.4 ± 0.5 ± 1 ± 2 ± 5210 / 410 – – – ± 1 ± 2 ± 2 ± 5410 / 610 – – – – ± 3 ± 4 ± 5Official error limits for thermometers containingwetting thermometric liquids, for the subdivisions:Temperature rangefrom °C/to °C0.5 °C 1 °C 2 °C 5 °C-200 / -110 – ± 3 ± 4 ± 5-110 / -10 ± 1 ± 2 ± 4 ± 5-10 / 110 ± 1 ± 2 ± 3 ± 5110 / 210 – ± 3 ± 4 ± 5Calibration / Temperature correction (approximation)Unless marked otherwise,thermometers are calibrated"for total immersion".This means that the meniscusof the mercury column is levelwith the surface of the liquidbeing measured.If part of the mercury columnis visible above the liquidsurface, a correction may benecessary.Equation for correction:t k= t + (t-t') n6250Example:Temp. reading: t = 160 °CImmersion point: t x = 85 °CEmerging mercurycolumn:Mean temperature: t' = 32 °CLength in °C(on scale): n = 160-85 = 75Corrected temp.: t k= 161.5 °Cwww.brand.de229