Described is a convection reducer. The convection reducer may be used in a thermogravimetric analysis apparatus to reduce convection in fluid surrounding a sample container. The convection reducer includes multiple baffle plates and at least one spine member. Each baffle plate has an edge with at least one slot and each spine member has multiple slots. Each slot in a baffle plate is received in a corresponding slot of the at least one spine member so that the baffle plates are arranged substantially parallel to each other along the at least one spine member. The reduction in convection results in undesired forces on the apparatus that may disturb the sample weight measurement.