Examples of Accuracy and Precision in Chemistry
The importance of accuracy and precision in chemistry is necessary to overcome errors in result and match the required set of parameters and standards.
To match these conditionalty’s one has to go through the entire analytical process and follow appropriate validation, suitable calibration leading to results that are traceable to International standards.
For a chemical analyst, accuracy becomes a reliable tool to cross check if the intended standards are matched with or not.
Measurements affect the daily lives of everyone and so we need to have sound accurate and reliable measurements which are essential to the function of modern society.
The role of chemical analysts remained same over the years but the instruments of measurements have changed over the years and have made the accuracy and precision in chemical analysis more potent.
For example when it was de-coded that carrots can help in preventing night blindness, it was an chemical analyst who segregated the various chemical components of carrot and identified the exact active component as beta-carotene and this could be exemplified with only accuracy and precision analysis of how much a person needs this yellow pigment per day to help prevent the blindness.
The issue of accuracy and precision sometimes leads to interesting and some dramatic consequences.
The quality of the balance we use to measure mass is important in a measurement and when speak about high quality measurement, what exactly we meant by that?
For chemist Faisclough- Baity, these two terms mean completely different things and for him accuracy relates to how close a measurement is to its true value while precision relates to how close repeated measurements are to each other whether they are accurate or not!
A set of measurements could be accurate or could be precise and sometimes can show both the characteristics and in some rare cases won’t show any of these.
But instruments fine tuned would definitely yield measurements that are both accurate and precise.
Let us now find out why it is important for us to know uncertainties in our measurements and to worry about precision and accuracy?
In most of the cases our lives, huge cash or our jobs could be at risk if we fail to do a proper measurements fo these and don’t know what we want these to do?
Similarly the dosage of drugs must be measured with utmost care and within known limits to avoid doing harm to us instead of drugs giving good result.
The amount of fuel loaded in a fighter aircraft is very critical as it has to go for specified sorties and return within a specified time frame and that calls for a very very precise measurement of the sorties and also impending enemy engagement in air.
The impure water that we intake could put all our lives in risk and so a accurate measurement is made to find the amount of bacteria and harmful planktons before a even more precise amount of anti bacteria treatment is carried out before released for human consumption.
The dosage of anesthesia given to a patient undergoing a general anethesia surgery is again speaks a volume of how accuracy and precision takes into account for our safety.
The amount of anesthesia required, the duration of surgery, the body weight, the blood – body weight ratio and blood type are all taken into account.
To assess the precision and accuracy of a different values the calculations must contain at least as much uncertainty as is present in the measured values we use to obtain these results and this means that when perform calculations we may not accept all of the digits appearing in calculator display as that definitely would make the calculations very clumsy and huge, but we do make arrangements to make these simpler on us.
The advent of significant numbers is one such action we undertake to make our calculations friendlier and closer to accuracy and more than most occasions we have a precise reading.
Examples of accuracy and precision may include the utilisation of this technique in forensic analysis which might be utilised for a speedy conviction of a guilty and or error leading into a situation where a guilty goes scot-free.
> In commerce the technique is used to match and set standards for different commercial goods to prevent sub-standards supply and also high cost involved in replacement and eventual loss to customers.
> This technique is used for better distribution of potable water and also used for detection of contaminants.
> Incorrect medication due to less precise formulation could lead to disaster and so this technique is utilised for better combination of active ingredients in a tablet.
> The changes in soil profile and analysis of this help us change the pH at right moment before a particular crop is cultivated.
> The pH of water is balanced with precise inputs from a chemical analyst to start any kind of pisci-culture practice.
> Geographical areas with less or no active salts like iodine can lead to health hazards like hyper and hypo thyroid diseases and to prevent such things we again need accurate and precise readings to identify the areas.
> We need precise and accurate readings of the collected samples to identify and help prevent the spread of vector borne killer diseases.
> The geographical areas with arsenic level higher in water needs these accurate and precise inputs to not only identify but also prescribe a proper dosage of anti-arsenic chemicals.
For any kind of analysis, the implications have to be taken care of before devising a sampling method and that leads a long way in getting the right amount and correct result.