Classes of accuracy represent characteristic of measuring means which is necessary for check of their compliance to state standards. Any errors or changes of parameters capable though so to affect device accuracy are provided in classes of accuracy. Classes of accuracy describe limits of deviations, admissible within the standard, from the reference size or value. Operating by accuracy classes substantially facilitates check of measuring funds for compliance to standards.
Instruction
1. In view of a variety of sizes and measuring instruments to offer some uniform way to index admissible errors it is represented impossible. Most often the class of accuracy is designated by the number equal to an admissible error which is expressed in percentage to real value of size.
2. In order that with definiteness to tell to what class of accuracy the device with which you deal belongs, you will need some reference books, or the Internet if it ""near at hand"" and also an opportunity to make some calculations.
3. Find in reference books or on the Internet summary tables with a complete description of the device considered by you, and it is better than family of devices. Find all main technical characteristics and parameters because, measuring everything manually, you risk to allow inaccuracy already at this stage. As a result, all inaccuracies by all means will affect a final error, and, respectively, and definition of a class of accuracy of the device.
4. Allocate those which will be necessary for calculation of direct operation of the device from all found parameters. Also separately note the parameters capable to affect indirectly results of measurements. They can not be useful, but it is just in case better that total technical characteristics were found.
5. Divide the sheet of paper into two parts. At the left write the ideal, expected results which have to turn out during the operation of the device under standard conditions. At the left write down the received results from your device under the conditions which are available for you. Try to be exact, use the calculator for calculation. Results in the left and right columns identical will not be. Your task is not to find a match, and with a bigger accuracy to take readings from the device and to write down them.
6. After you wrote down all data obtained from your device, subtract from them ideal standard results. Find an arithmetic average. It will also define a class of accuracy of your device, namely, percentage coefficient of its error.