Standard Practice for Using a Guarded-Hot-Plate Apparatus or Thin-Heater Apparatus in the Single-Sided Mode

Importancia y uso:

4.1 This practice provides a procedure for operating the apparatus so that the heat flow, Q′, through the meter section of the auxiliary insulation is small; determining Q′; and, calculating the heat flow, Q, through the meter section of the specimen.

4.2 This practice requires that the apparatus have independent temperature controls in order to operate the cold plate and auxiliary cold plate at different temperatures. In the single-sides mode, the apparatus is operated with the temperature of the auxiliary cold plate maintained at the same temperature of the hot plate face adjacent to the auxiliary insulation.

Note 4: In principle, if the temperature difference across the auxiliary insulation is zero and there are no edge heat losses or gains, all of the power input to the meter plate will flow through the specimen. In practice, a small correction is made for heat flow, Q′, through the auxiliary insulation.

4.3 The thermal conductance, C’, of the auxiliary insulation shall be determined from one or more separate tests using either Test Method C177, C1114, or as indicated in 5.4. Values of C’ shall be checked periodically, particularly when the temperature drop across the auxiliary insulation less than 1 % of the temperature drop across the test specimen.

4.4 This practice is used when it is necessary to determine the thermal properties of a single specimen. For example, the thermal properties of a single specimen are used to calibrate a heat-flow-meter apparatus for Test Method C518.

Subcomité:

C16.30

Referida por:

C1045-19, C1470-20, C1558-24, C1130-24, C1114-06R19, C1043-24, C0177-19E01

Volúmen:

04.06

Número ICS:

17.200.10 (Heat. Calorimetry)

Palabras clave:

guarded-hot-plate apparatus; heat flow; single-sided; steady state; thermal insulation; thin-heater apparatus;