A microcalorimeter for the determination of combustion heat based on the principle of differential heat flow

•Established a microcalorimeter based on the principle of differential heat flow.•The oxygen bomb is cleverly designed as a multilayer structure.•Soaking block and heater ensure calorimeter temperature fluctuation 0.001 ℃/24 h.•Differential connection of two 3D sensors composed of 960 pairs of thermocouples.•Calorimeter can achieve automatic collection and processing of data information.