Aerometer :
Instrument for measuring weight and density of air and gases.
Altimeter :
Instrument used in aircraft to measure altitude.

Ammeter :
Instrument used to measure electrical current flowing in a circuit.
Anemometer :
Instrument to measure the force and velocity of wind.
Audiometer :
Instrument to measure intensity of sound.
Barometer :
Instrument used to measure the atmospheric pressure.
Calorimeter :
Instrument used for measuring quantities of heat.
Cardiogram :
A medical instrument for tracing heart movements.
Crescograph :
Instrument for use in recording growth of plants.

Dynamo :
Instrument for transforming mechanical energy into electrical energy.
Fathometer :
Instrument used for measuring depth of the ocean.
Geiger Counter :
Instrument for recording the amount of radiation emitted by a source of radio-activity.
Hydrometer :
Instrument used for measuring the specific gravity of liquids
Hydrophone :
Instrument used for recording sound under water
Hygrometer :
Instrument for measuring the amount of water vapours (humidity) in the atmosphere.
Kymograph :
Instrument used to record graphically various physiological movements i.e.,blood pressure,heart beating, study of lungs etc. in living beings.
Lactometer :
Aparatus used for measuring the purity of milk.
Manometer :
Apparatus used for determining the pressure of a gas.
Odometer :
Instrument by which the distance covered by wheeled vehicles is recorded.
Oscillograph :
Instrument for recording electrical or mechanical vibrations.
Photometer :
Apparatus used to compare the illuminating power of two sources of light.
Pyrometer :
Instrument for recording high temperatures froma great distance.
Radiometer :
Instrument for measuring the emission of radiant energy.
Rain gauge :
Apparatus for recording of rainfall at a particular piece.
Refractometer :
Instrument to measure refractive indices.
Saccharimeter :
Instrument for determining the amount of sugar in a solution.
Sextant :
An optical instrument used for finding out the altitude of celestial bodies and their angular distances.
Sphygmomanometer :
Instrument used for measuring arterial bolld- pressure.
Spherometer :
Instrument for measuring curvature of surfaces.
Seismograph :
Instrument used for recording earthquake shocks.
Tachometer :
Instrument for determining speeds of aeroplanes and motor boats.
Thermostat :
Instrument used to regulate the temperature to a particular degree.
Transformer :
An electrical apparatus used to convert high voltage to low and vice versa