Physics Measuring Instruments

Buret is a graduated glass tuble with a top at one end, for delivering volumes of liquid. Since, it is graduated, it is most suitable for reading a meniscus.

Graduated cylinder is measuring cylinder used to measure the volume of liquid or gas. It has a narrow cylinderial shap. Each marks as line/graduations in cylinder represents the amount of the liquid or gas that has been measured. Thus, it can be used to make precise measurements for the volume of gas collected over wales.

A thermometer is the standard instrument used to measure temperature.

In 1643 Torricelli made an instrument for measuring atmospheric pressure. This device is called a barometer. This barometer can be either mercuric or aneroid barometer. 

Rainfall is measured by a precise instrument called Rain gauze. It determines the depth of precipitation that occurs over a unit area. Thus, it measures rainfall. One liter of rainfall per meter squared is equivalent to one millimeter of measured precipitation. A funneled aperture of 150-170 cm is found in standard rain gauges. They are designed as a simple passive collector. A graduated measuring glass is used for determining the amount of precipitation.

Temperature is measured based on the freezing and boiling points of water. In 1948 the Centigrade scale renamed it the "Celsius" temperature scale and most countries use the Celsius scale. Indian, and several other countries, use the Fahrenheit system of temperature measurement mainly because from the British time only Fahrenheit thermometers were available in India. It is only after the invasion of Chinese thermometers that we have flat ones that show both centigrade/ Fahrenheit scale.

Degree of the heat of our body is known as temperature. The instrument which is used to measure the temperature is known as a thermometer. Thermometers are of two types:

• Clinical thermometer and Laboratory thermometer. They have different markings, but they work in the same way.  In the thermometer, a glass tube is filled with mercury. Mercury is used to measure temperature because it changes from a solid to liquid very easily.

The instrument which is used to measure the temperature is known as thermometer. Thermometers are of two types:

• Clinical thermometer and laboratory thermometer. Clinical thermometer is used for measuring the temperature of body and laboratory thermometer is used for measuring the temperature of atmosphere. They have different markings, but they work in same way.  In the thermometer, glass tube is filled with mercury. Mercury is used to measure temperature because it changes from a solid to liquid very easily.

Rain gauge can accurately measure the rainfall without any loss due to evaporation. It is an instrument used for determining the depth of precipitation that occurs over a unit area. Thus, it measures rainfall. One litre of rainfall per meter squared is equivalent to one millimeter of measured precipitation. A funneled aperture of 150-170 cm is found in standard rain gauges. They are designed as a simple passive collector. A graduated measuring glass is used for determining the amount of precipitation.

To measure the minimum and maximum temperature in a day, Six’s thermometer is used.  It consists of a U-shaped capillary tube having bulbs at both ends. Mercury is filled in the bend of the U-tube. One of the bulbs is completely filled with alcohol and the other bulb is partly filled with alcohol. Alcohol is the thermometric liquid in case of Six’s thermometer. Change in temperature is recorded due to expansion and contraction of alcohol.

Stevenson screen is used for providing shelter for meteorological instruments, particularly wet and dry bulb thermometers. It is kept 1.25 meters above the ground by legs. It is done so to avoid strong temperature gradients at ground level. Stevenson screen has sides to encourage the free passage of air. For reflecting heat radiation, it is painted white. It was invented by the British engineer and meteorologist Sir Thomas Stevenson.

A device which is used to measure atmospheric pressure is known as Barometer. There are two types of barometers:- mercury and aneroid.

Atmospheric pressure is balanced by a column of mercury in case of a mercury barometer.

Aneroid barometer also called non-liquid barometer. Because of its smaller size and convenience, it is widely used in portable instruments and in aircraft altimeters.

• Thermogram is an instrument which is used for creating images based on heat radiation emitted from any object. It has many applications ranging from medical settings to weather stations. Hence A is the correct option.
• The thermometer measures the temperature of the human body.
• Isotherms are the lines joining various points on the map having the same temperature during a given period. Hence B and C are incorrect.

A Thermogram is a modern instrument that continuously measures and records the temperature and is used in weather stations. It provides information in form of a graph called thermograph.

Thermographs are a good alternative to the digital collection of data. The thermographs are equipped with mechanical or quartz clockwork. Easily it can be switched from weekly recording to daily or monthly recording. They will be delivered with writing pens and a recording paper.

To measure the minimum and maximum temperature in a day, Six’s thermometer is used.  It consists of a U-shaped capillary tube having bulbs at both ends. Mercury is filled in the bend of the U-tube. One of the bulbs is completely filled with alcohol and the other bulb is partly filled with alcohol. Alcohol is the thermometric liquid in case of Six’s thermometer. Change in temperature is recorded due to expansion and contraction of alcohol.