mesurment is essentially an act or the result of a cointative comperision between a given quantity and a quantity of tha same kind selected as unit
the result of mesurment is expressed by a number reprasantation a ratio of the unknown quantity to thne addopted unit of mesurment the physical embodiment of the unit of mesurment as well as thet of its sub mulktipole or multiple value is nreffered to as a studered . the device used for comparing the unknown quantity whit the unit of mesurment or a stantard quantity is knoiwn as a mesurment instrument
two types of mesurment are ussed to obtain thje walue of unknown quantity which are direct mesurmentr anmd inderict mesurment
in electricalliy engineering practice defraction method of direct mesurment are most widelly ussed begin the most simple and least time consuming through there accuracy is not more than 0.2 to 10% . direct mesurment have the advantages of introducin
g a s,,maller error then that obtain in inderict mesurment . in direct mesurment ythe maxximum possible error of mesurment dependss uponb the accuracy class of the mesurring iinstrument ussed 
the international standurds are defined on the basses of internatuional aggraiment accracyu with presnt day the technological and syntific method international menthod are chequed and evoluate regurlly against abslute mesurmkent in the term of fundamental units the in ternational standurd are maintained at the international bueoro of wait and mesurment are nt available to tyhe ordinarry usser of mesurring instrument for the purposs of claibration and comnparision 
primnary standart of nabslute standard of such accuracy that they csn be used as tha ulrtimate referece standards the primary standard with fundamerntal units and sum of the drived electricatal and mechnicl uniot are indepenf are clallibrated by abslute mesurment eachj of the national laboratry the result of these mesurmenbts are comnpare against each othere leading to a word average figure for the primarry standurd are nt available fr use outside the national laboratries one of the main function of the priomarry standurds is the varification and callibration of secondarry standurds thwe primarry standurds are fwe in numbers.
n+ following are the source of errors
insufficient knowledge of vprocess paramneters and design conditions
poor design
poor mainaenance
change in process parameters, irregularations, upset,etc.
certain design limitations
errors caused by the person oprating the instrument or equipment.
mesurment is the process of comparing an unknown quality with an accept standard quanbtity. it iunvolves connecting a mesuring binstrument into system reeponding on the various type og the mesurring since it is very difficult to define the true value the term expected value is used anty messurment is affected by many variables, thererfore the result rarely reflect the expected value foir exampole distreubs the circuit causing, ,df some factors that affect thge mesurment is affected some factors bthet affect the mesurment are related to trhe poersonb using the instrument. the degree to which in trerspof the errorsd of mesurment.
errtors id bthe devations from the true value tujh s dur joi hota hu tokkda tookda rhta bhu is lifre y gandu pachori h m.c sabse bada bhadwa h is karan y gandu khlata h to the principlle i beg to say thert i lost bmy mobile i want mobile so plz give me some mobilke from which i can buy some of the mobile like underv b connecting a messuring instrument into the catagorrty through which it gets immit and that flow through the massive round of bablaough by thata gift of godv ut\ self that conclude a buccut and fronbdudr u sdtkiswted 
accuracy of the erlement that include the moist essantiol ways that itself may conclude the various errors called the essentiol vays through the most conduc tive element accuracy bthe metals and the variouis elementy the metals like the most essential; elements arfe conclude the amount the accuracy of tyhe instrument can be given by the following expressions
percentage of true value
