BS 196-9:2010 pdf download – Methods of testing cement Part 9: Heat of hydration — Semi- adiabatic method 4.3 Platinum resistance thermometers, for the reference calorimeter and each test calorimeter, having a minimum range 19 °C to 75 °C. If the conductors of the electrical resistor are made of copper they shall have a sectional area not greater than 0,25 mm 2 in the part which passes through the stopper. If they are made of another metal the total thermal resistance per centimetre of conductor shall be greater than 0,10 K⋅mW -1 (thermal resistance equivalent to that of a copper conductor with a sectional area of 0,25 mm 2 and 1 cm in length). The thermal output of the thermometer shall not exceed 3 mW. Direct current supply, which constitutes a power input, shall be avoided if the thermal output exceeds 0,2 mW. It is advisable to ensure the accuracy of the overall temperature measuring and recording equipment. The temperature of the test sample shall be measured to an accuracy of ± 0,3 °C. Where the calorimeter is calibrated in situ with the conductors used for the tests of heat of hydration, the total sectional area of the conductors will be a maximum of 0,80 mm 2 (four wires 0,5 mm in diameter), but shall be such that the coefficient of heat loss of the calorimeter is less than 100 J⋅h -1 ⋅K -1 for a temperature rise of 20 K (see A.3.1.1). The protective sheath of these conductors shall be made of a material having a low thermal conductivity. 4.4 Mortar box, consisting of a cylindrical container fitted with a cover, having a volume of approximately 800 cm 3 , designed to contain the sample of mortar under test. The mortar box, discarded after each test, shall be impermeable to water vapour. This shall be checked in use by weighing the mortar box after each test (see 5.2.3). It shall be made of electrically counter welded tin plate of nominal thickness 0,3 mm; have a diameter of approximately 80 mm and a height of approximately 165 mm. Its height shall be designed to provide an air space of approximately 10 mm between the top of the mortar box and the stopper. The lid of the mortar box shall be fitted with a central thermometer pocket in the form of a cylindrical pipe, closed at its base. The internal diameter...
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