Techniques for Measurements

Measuring Techniques Techniques 1. If accuracy is desired desired for an an experiment, experiment, what measuring devices would you you use for for small volumes of liquid material like 60mL which is equivalent equivalent to 1! cup  — a "#0mL graduated  — cylinder, a 100mL, a standard measuring cup or a pint cup$

Given the question we must use any such material which could measure liquids. A 100 mL measuring device would be the most appropriate choice because it is closest to 60mL. The closer amount to 60mL will give more accurate results.

". %ow many many times would would you &e multiplying multiplying your your errors when measuring measuring ! cups in a regular regular standard cup compared to using a large quart cup$

Quart are larger than cups! one quart ma"es up # standard cups $% o&. 'rrors should be multiplied (our times! because measuring big amounts with small measuring tools will give bigger errors. '. (hy does plastic shortening shortening like like margarine margarine or &utter weigh weigh less less per cup cup than a melted on on or than cooking off$ (hat makes the volume of the plastic shortening$ If consistent amount of fat is desired to maintain the proportion of this ingredient in a recipe, would you measure its volume or its weight$ (hy$

)utter contains around %0* (at while margarine contains up to %0* vegetable (at. +preads that contain less than %0* (at by weight and have more water. Tubs Tubs o( butter or margarine have air whipped in them! ma"ing only stic"s should suitable (or ba"ing. ,lastic shortening weighs less per cup than i( melted because a solid material will be denser than liquid material when the materials are similar! or almost identical. -eighing is better than using volumes (or recipes. -eight is constant! but the way a cup is (illed (i lled changes each time.

!. (hy would itit &e all right right to stir the the no)sift or pre)sifted flour flour *as indicated indicated in the la&el+ in the &ag  and fill the cup &y spoonfuls$ xplain on the &asis of deviation of weights o&served in the class exercise. (hat deviations in weight per cup are allowed as tolera&le &ecause they are not significant$

The point o( si(ting (l our used to be to remove lumps and the occasional insect! although (lour is generally (ree o( those concerns nowadays. +i(ting loosens up (lour that has been sitting around in storage! aerating it can help your goods to have a lighter teture. )y moving around pre/si(ted (lour! or pouring it (rom one container or measuring device to another! the way it is pac"ed is altered. n a way you can say that the (lour was unsi(ted . ,roper si(ting is done straight into the measuring device.

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rom the eercise it was seen that the si(ted (lour was much lighter then the unsi(ted (lour. rom the eercise the (ollowing table shows the values and deviations obtained.

#. (hen would a weighing scale &e accurate and precise$ (hen is it precise &ut inaccurate$ -oes this also hold true for a thermometer, a timer or a clock$ xplain.

,recision is the closeness o( measured values to each other. Accuracy! on the other  hand! is how close a value is to the accepted value. -hen using a weighing scale! the values are accurate and precise when the values are close to the eact value being measured and the measured values (rom the trials done are close to each other. The values will be precise but inaccurate when the measured values have decimals because the values may be near to each other but the eact value was not ta"en. The measurement o( the actual temperature o( a liquid is ta"en with a thermometer. The accuracy and precision o( the thermometer are a((ect such measurement! but good technique is also important (or measurement. t is quite possible (or an instrument to be precise! but inaccurate. 2(ten times it is easy to get precise values (rom a thermometer! but the degree o( accuracy is o(ten dependent on the one reading the values.

6. (hat is the difference &etween a thermometer and a thermostat$

 A thermometer is used to measure the temperature o( a certain ob3ect! (ood or area. There are many di((erent types o( thermometers. A thermostat has a thermometer built into and is used to control the temperature in a certain place and maintain it. 4ou can control thermostats! but you cannot control thermometers.

. (hen an oven has a thermostat setting of 1  0 /, and the oven thermometer reads 16' 0 /, how should you reset the thermostat to have the two agree$ If the thermometer reads 11 0 /, how should the thermostat &e reset$ xplain differences in &aking time on the &asis of the facts suggested in this exercise$

 A thermostat senses the temperature o( a system so that the system5s temperature is maintained at a certain point. The thermostat does this by switching heating or cooling devices on or o((! regulating the (low o( a heat trans(er (luid as needed. A thermostat is a control unit (or a heating or cooling system! they use a variety o( sensors to measure the temperature. The output o( the sensor then controls the heating or cooling apparatus. The output is not proportional to the di((erence between actual temperature and the set temperature. The thermostat runs at (ull capacity until the set temperature is reached! then shuts o((. ncreasing the di((erence between the thermostat setting and the desired temperature does not shorten the time it ta"es to achieve the desired temperature. To reset the thermostat temperature we have to increase by 1# 0  to ma"e it by 1## 0 . . xplain why the two methods in exercise "2.' num&er " have equal product *soft)&oiled egg+.

The products in the eercise turned out the same because temperature and time are inversely proportional to each other. n the eercise the temperature in the top part o( the boiler was lower! and the egg was coo"ed longer. At the bottom o( the double boiler!

the egg was coo"ed (or a shorter period o( time because the temperature was higher. The higher the temperature given o((! the shorter time the egg is coo"ed (or and vice versa.

. Look up the proper use of the oven, the &roiler of a gas)fired oven and that of an electric range. -ifferentiate &etween oven &aking and pan &aking.

The oven is a "itchen appliance used (or roasting and heating. ood coo"ed in ovens o(ten include meat! casseroles and ba"ed goods and other desserts. An oven is (irst turned on preheated to a speci(ic temperature be(ore the (ood is added. )roiling is a great method (or getting grill/li"e results in the "itchen. )oth grilling and broiling are (ast and easy! and both use direct! high heat to brown and coo" (ood. 7ost (ood will be (inish coo"ing in 8/10 minutes. t may easily go (rom having a nice sear to a burn. 2nly the outer sur(aces o( the (ood is being coo"ed! which is why thin cuts o( meat! quic"/coo"ing (resh vegetables! and tender (ood are ideal (or broiling. An electric range is a stove that converts electrical energy into heat to coo" and ba"e. 'lectric stoves are not as great compared to gas stoves because it ta"es longer (or the heating element to ta"e e((ect! and a while (or it to cool down a(ter the heat has been reduced. 'lectric stoves require (lat/bottom pots! because the coo"ing sur(ace is shaped that way. onvection ovens and traditional ovens are di((erent (rom one another. onvection ovens ba"e 98 0  hotter than traditional ones. onvention ovens use a (an to blow the hot air to circulation in the oven! allowing the product to ba"e (aster and easily. onvection ovens are good (or treats li"e pies or coo"ies! but not (or ca"e.

References:

)rown! A. $9011&. :nderstanding (ood; ,rinciples and ,reparation $#th ed.! p. <&. -adsworth; engage Learning. ’

Luna! 7? $9008&. Guman s ntroduction to ood ,reparation. 7anila; 7erriam and -ebster! nc. 7easuring techniques. $9018&. @etrieved August 1#! 9018! (rom http;www.recipetips.com"itchen/tipst//1111measuring/techniques.asp