A hygrometer is an instrument used to measure relative humidity.
A psychrometer is an example of a hygrometer.
A psychrometer uses two thermometers to measure relative humidity, one measures the dry-bulb temperature, and the other measures the wet-bulb temperature.
Humidity is the measure of the amount of moisture in the air.
Hydrometer operates based on the Archimedes principle that a solid body displaces its own weight within a liquid in which it floats.
A pyrometer is an instrument that measures temperature remotely by measuring the intensity of radiation from the object, without having to be in contact.
It has two categories - optical pyrometers and infrared/radiation pyrometers.
The specific gravity of milk is determined using the lactometer, an instrument which sinks to a definite point in pure milk.
It consists of a test-tube and a meter blub.
The most abundant proteins in bovine milk are caseins and some of the whey proteins, namely beta-lactoglobulin, alpha-lactalbumin, and serum albumin.