Question

Q) Write the problems caused if an uncalibrated machine is used for some analysis?

Answer 1

The result of any analysis will always be incorrect or it may be some blunder if the machine used for measurement is uncalibrated.Either its be pH meter or weight measurement or temperature measurement devices like thermocouple or pressure drop measuring devices like manometer,everyone has its own significance for practical purposes.

Let us understand it with an example.Suppose you are measuring weight of a particular reactant on beam balance and the the machine is in not well calibrated.So what will happen,it will show you the weigh of the sample different from its actual weight.Now you wanted to use that reactant for some reaction and you measured your weight based on the desired amount you wanted for reaction.Now as we know the concept of limiting reactant and excess from the reaction point of view,since the weight has been differed so the number of mole of components will also be different from the desired one.Once the reactant is consumed the product formed may not have desired composition as calculated on the basis of stoichiometric coefficients.And if the reaction is exothermic,then it is going to affect the reactor temperature as well,which might be crucial from the purpose of safety on an Industrial scale.

Example 2: Similarly it should be confirmed that the level of mercury in both the limbs of a U-tube manometer is leveled equal before the experiment and it should be free from air.Otherwise during the actual flow of liquid the pressure drop calculated through manometer will not be only due to actual flow rate of liquid but also due to the pressure diffrence already existing in the limb of manometer because of diffrence in height of the mercury before the start of the experiment.This is important to do because we calibrate venturimeter,orificemeter or other flow measuring devices based on the pressure drop observed.And once our calibration is wrong,our flow measuring devices will not depict actual flow rate and hence it could be very problemastic at industrial scale where we deal with large amount of flow rate either for liquid or gas and thus there can be pressure build inside the reactor because of incorrect flow rate.

So from above examples we understand,an uncalibrated machine will give a different measurement than actually it should give.Because of this basic calibration error,when we are going to process that material it will result further degradation in the quality of intermediate and end product as well.Also this will be a much threat from the safety point of view.