A measuring instrument for thermogravimetrically determining the moisture content of a material, which includes a base (12), configured as a balance, with a base surface (22), and a hood (14) pivotably connected to the base. The hood has a weighing chamber lid (50), weighing chamber walls (52-56) and a heating element (44). The hood consists of an electronics module (36) that includes the heating element and an electronic power unit, and of a mechanical module (48) that includes the weighing chamber lid and all of the weighing chamber walls. The mechanical module (48) is rigidly and reversibly coupled to the electronics module so that the heating element, protrudes from a main body (42) of the electronics module and rises through a corresponding opening (58) in the rearward weighing chamber wall (56), with the main body being pivotably connected to the base and surrounding the electronic power unit.