com www.GOALias.blogspot.com www.GOALias ... - fun learning

www.GOALias.blogspot.comclinical thermometer. Record yourobservations as in Table 4.2.Is the body temperature of everyperson 37°C?The temperature of every person maynot be 37°C. It could be slightly higheror slightly lower. Actually, what we callnormal temperature is the average bodytemperature of a large number of healthypersons.The clinical thermometer is designedto measure the temperature of humanbody only. The temperature of humanbody normally does not go below 35 o Cor above 42 o C. That is the reasonthat this thermometer has the range35 o C to 42 o C.Boojho got a naughty idea. Hewanted to measure the temperatureof hot milk using a clinicalthermometer. Paheli stopped himfrom doing so.CAUTIONDo not use a clinical thermometer formeasuring the temperature of anyobject other than the human body.Also avoid keeping the thermometer inthe sun or near a flame. It may break.4.3 L4.3 LABORATORYTHERMOMETERHow do we measure the temperature ofother objects? For this purpose, thereare other thermometers. One suchthermometer is known as the laboratorythermometer. The teacher will show youDifferent types of thermometersare used for different purposes.The maximum and minimumtemperatures of the previousday, reported in weatherreports, are measured bya thermometer called themaximum-minimumthermometer.this thermometer. Look at itcarefully and note the highest andthe lowest temperature it canmeasure. The range of alaboratory thermometer isgenerally from –10°C to 110°C(Fig. 4.4). Also, as you did in thecase of the clinical thermometer,find out how much a smalldivision on this thermometerreads. You would need thisinformation to read thethermometer correctly.Let us now learn how thisthermometer is used.Activity 4.4Take some tap water in a beakeror a mug. Dip the thermometerin water so that the bulb isimmersed in water but does nottouch the bottom or the sides ofthe container. Hold thethermometer vertically (Fig. 4.5).Observe the movement of mercuryin the thermometer. Wait till themercury thread becomes steady.Fig. 4.4 A laboratory thermometer38SCIENCE