GRAVIMETRIC ANALYZER

PROBLEM TO BE SOLVED: To enable the measurement of a change in the weight of a microwave irradiated sample caused by the thermal cracking, attraction, desorption or the like to be measured by connecting a sample weight measuring instrument to a sample tray in the microwave irradiated box body through a strut penetrating the bottom plate of the box body. SOLUTION: A sample tray 3 is mounted to the tip of a weight measuring strut 5 penetrating a hole 21 in the bottom plate 31 of a box body to be located in the frontage of a microwave irradiated window connected to a microwave irradiated wave guide 19. An optical fiber thermometer unaffected by the microwave is used as a temperature sensor 10. A sample temperature sensor 7 of a non-contact type one measures temperature with an infrared ray generated from the sample 4. A high sensitivity balance is used for a sample weight measuring instrument 14 and connected to the sample tray 3 through a strut 5. The weight information of the sample 4 obtained from the weight measuring instrument 14 is sent to a recorder 16 so that the sample weight is recorded as time goes on. The same kind of existing product as a heater such as an electronic range may be used for a microwave oscillator 18 and the wave guide 19.