Apparatus for recording, transmission, processing and reproduction of sound, images or data; Computer-controlled apparatus for testing and measuring viscosity, porosity, expansion, surface tension or the like; instruments and apparatus for measuring or checking quantities of heat, sound or light (including exposure meters); microtomes; and the electrochemical properties of aqueous solutions, including these parameters: pH, ORP, TDS, salinity, conductivity, resistivity, dissolved oxygen, ion, turbidity, temperature; Electric control devices for physical or chemical analysis (for example, polarimeters, refractometers, spectrometers, gas or smoke analysis apparatus); instruments and apparatus for measuring or checking viscosity, porosity, expansion, surface tension or the like; instruments and apparatus for measuring or checking quantities of heat, sound or light (including exposure meters); microtomes; Electronic apparatus for testing the electrical conductivity of physical or chemical analysis (for example, polarimeters, refractometers, spectrometers, gas or smoke analysis apparatus); instruments and apparatus for measuring or checking viscosity, porosity, expansion, surface tension or the like; instruments and apparatus for measuring or checking quantities of heat, sound or light (including exposure meters); microtomes; Electronic apparatus for use in the treatment of aqueous systems, namely, for analysis of the system conditions for the purpose of applying the appropriate chemical treatment; Electronic navigational and positioning apparatus and instruments; Laboratory apparatus and instruments for extracting information as related to polarimeters, refractometers, spectrometers, gas or smoke analysis, and for measuring or checking viscosity, porosity, expansion, surface tension or the like; instruments and apparatus for measuring or checking quantities of heat, sound or light (including exposure meters); microtomes; Measuring apparatus, namely, sizers for physical or chemical analysis (for example, polarimeters, refractometers, spectrometers, gas or smoke analysis apparatus); instruments and apparatus for measuring or checking viscosity, porosity, expansion, surface tension or the like; instruments and apparatus for measuring or checking quantities of heat, sound or light (including exposure meters); microtomes; Scientific apparatus, namely, cellular mixed ester membranes for use in the science and research industry; Thermo-hygrometers