"measuring instrument"

means any appliance, equipment, instrument, apparatus or other thing or any combination thereof by means of which a measurement of physical quantity, expressed in any measuring unit or a mathematical function of measuring units, may be made, and includes any appliance, equipment, instrument, apparatus or other thing or any combination thereof by means of which a grading or counting in connection with the measurement of any physical quantity or a counting by means of gravitation may be effected;

[Definition substituted by section 1 of Act No 34 of 1975.]