How to Determine Equipment Accuracy for Test Method Specs

Often, published test methods give guidance as to the type of test equipment needed to perform a test, but do not always clearly specify the accuracy requirements of test equipment to be used for that test. One might go on a research expedition to determine if other reference exist that provide the guidance on the needed test equipment specifications. So how do we know the appropriate test equipment accuracy for use in a test? For example, a test method might specify an instrument "with readability to 0.01 units". Does that mean the instrument needs to be accurate to 0.01 units? No! And it can be expensive to buy an instrument to meet an accuracy that is tighter than you really need. Conversely, it can be a waste of money and impart too much risk to get test equipment that is not accurate enough. Learn how to interpret test method specifications and determine the most appropriate test equipment, and subsequently the calibration needs of the test equipment.