I think you are simply looking for the word #"accuracy"#...
Explanation:
#"Accuracy"# just reflects the closeness of the measured value to the #"true value"#, whatever this is. #"Precision"# refers to the repeatability of the measurement. An accurate measurement may be imprecise (i.e. irrepeatable), and a precise measurement may be inaccurate (i.e. it may suffer from a systematic error)... This will be explained better in your analytical text...