• Altimeter – An instrument used for measuring altitudes in aircraft.
• Ammeter – An instrument for measuring electric currents in amperes.
• Anemometer – An instrument for measuring the force and velocity of wind.
• Audiometer – An instrument for measuring the intensity of sound.
• Audiophone – An instrument for improving imperfect sense of hearing.
• Barometer – An apparatus used for measuring the atmospheric pressure.
• Calorimeter – An instrument used for measuring quantities of heat.
• Carburettor – An apparatus used in an internal combustion engine for charging air with petrol vapour.
• Cardiograph – A medical instrument for tracing heart movements.
• Chronometer – An instrument kept on board ships for measuring accurate time.
• Crescograph – It is used for measuring growth in plants.
• Dynamo – The origin of electricity in a dynamo is the transformation of mechanical energy into electrical energy.
• Galvanometer – An instrument for measuring electric currents of small magnitude.
• Hydrometer – An instrument used for measuring the specific gravity of liquids.
• Hydrophone – An instrument for recording sound under water.
• Hygrometer – An instrument for measuring humidity in air.
• Lactometer – An Instrument for measuring the relative density of milk.
• Manometer – An instrument for measuring the pressure of a gases.
• Mariner's compass – An apparatus used by sailors to know the direction. The needle always points north-south.
• Microphone – An instrument used for converting sound waves into electrical vibrations and to magnify the sound.
• Microscope – An instrument used for magnifying minute objects by a lens system.
• Odometer – An instrument by which the distance covered by wheeled vehicles is measured.
• Phonograph – An instrument for reproducing sound.
• Photometer – It is an instrument for measuring the intensity of light; a device for comparing the luminous intensity of sources of light.
• Polarimeter – An instrument used for measuring optical activity.
• Pyrometer – An instrument for recording high temperatures from a great distance.
• Radar – It is an abbreviated form of Radio, Angle, Direction and Range. It is used for detecting the direction and range of an approaching plane by means of radio microwaves.
• Rain Gauge – An apparatus for recording rainfall at a particular place.
• Radiometer – An instrument for measuring the emission of radiant energy.
• Refractometer – An instrument to measure refractive indexes.
• Seismometer or Seismograph – An instrument for recording earthquake shocks.
• Sextant – An instrument used for measuring the altitude of the sun and other heavenly bodies.
• Spectrometer – An instrument for measuring the energy distribution of a particular type of radiation.
• Speedometer – An instrument which indicates the speed at which a vehicle is moving.
• Spherometer – An instrument for measuring curvature of surfaces.