Sample Holder:

The sample holders range from flat plates to deep crucible of several capacities. The shape of the TG curve will vary as the sample will not be heated within identical condition. Commonly, it is preconditioning in which the thermocouple is placed on near the sample as probable and is not dipped into the sample since it might be spoiled because of sticking of the sample to the thermocouple on heating. So fact sample temperature is not recorded, it is the temperature at a few point in the furnace near the sample. Therefore it leads to source of error because of the thermal lag and partly because of the finite time taken to cause detectable mass change. If the sensitivity of recording mechanism is not sufficient to record the mass change of the sample then this will also cause error in recording the weight modify of the sample. If the composition of the sample holds is such in which it reacts either along with the sample, or product created or the evolved gases then this will cause error in recording the mass change of the sample.