4.1.4 Experimental procedures
(1)Preparation before measurement:arrange the instruments according to Figure 4.1.2,connect the circuit,set the digital multimeter at 200 mV DC voltage tap.
(2)Measure the thermo-electromotive force and calibrate the thermocouple thermometer.
①Measure the thermo-electromotive force at low temperature(cold water).
②Rise the water temperature and then measure the thermo-electromotive force.Turn on the electric furnace,heat the beaker,then measure the thermo-electromotive force and corresponding temperature according to the temperature setting schedule.(https://www.daowen.com)
③Cool down the water temperature,and measure the thermo-electromotive force.In order to eliminate the error caused by the thermal inertia of the mercury thermometer on the basis of step②,pour some cold water into the beaker to make the water temperature drop to the corresponding temperature measured in the temperature rising process.Then measure the thermo-electromotive force Et again at the same temperature to find the average thermo-electromotive force Et.
④Use the thermocouple thermometer to measure the temperature of water,and then calculate the absorption rate of microwave by water.
