Alcoholmeters; Refractometers; Antifreeze testers; Apparatus for testing gas, liquids and solids; Diagnostic apparatus for identifying refrigerant type and purity in automobile air conditioning systems; 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; Fiber optic instruments, namely, transceivers; Instruments for measuring milk quality parameters; LED microscopes; Liq...