The true value of a measurement is the value towards which independent measurements tend, when performed by different competent persons, and using different methods. Note the word "Tend".
Accuracy is the amount by which your measurement differs from the true value.
Accuracy :D
Accuracy
Precision -- the degree to which the result of a measurement, calculation, or specification conforms to the correct value or a standard
Depends on you
Definition of Precision: Referring to how close a group of measurements are to each other. Accuracy: Refers to how close the measurement is to the true or accepted value. If the volume of the water was 20 L and I measured it wrong one and got 19, measured it again and got 19, and then measured it a third time and got 19, that would be a PRECISE measurement, since you got the same result three times in a row. It's INACCURATE because it isn't the CORRECT measurement. Hope that helped!
Accuracy :D
False
Accuracy
Precision -- the degree to which the result of a measurement, calculation, or specification conforms to the correct value or a standard
Depends on you
Approximation
This value is variable, for each type of measurement.
It's signature figures
Definition of Precision: Referring to how close a group of measurements are to each other. Accuracy: Refers to how close the measurement is to the true or accepted value. If the volume of the water was 20 L and I measured it wrong one and got 19, measured it again and got 19, and then measured it a third time and got 19, that would be a PRECISE measurement, since you got the same result three times in a row. It's INACCURATE because it isn't the CORRECT measurement. Hope that helped!
A measurement close to true size is referred to as Precision Measurement.
Accuracy in measurement and instrumentation refers to how close a measured value is to the true or known value. It is a measure of systematic error, which denotes how well the instrument or measurement device is calibrated and free from biases. The accuracy is usually expressed as a percentage of the measuring range or as a specified number of units.
When measuring, there are two types of deviation, accuracy and precision. A measurement is close to the accepted value when it his highly accurate.