SCIENTIFIC, OPTICAL, ELECTRIC, WEIGHING, MEASURING, SIGNALING AND CHECKING APPARATUS AND INSTRUMENTS, NAMELY MAGNETIC SUSPENSION BALANCES, RECORDING MICROBALANCES AND CALORIMETERS, USED FOR MEASURING MASS CHANGES AND MATERIAL TRANSFER RESULTING FROM ADSORPTION, ABSORPTION, EXTRACTION, POLYMERIZATION, COATING AND DRYING OF SOLID OR LIQUID SAMPLE MATERIALS UNDER CONTROLLED ENVIRONMENTAL CONDITIONS