2. Calculation method for accuracy

Step 1: Calculate the standard deviation. Perform n (usually 10-20) repeated measurements on the same sample using this instrument to obtain a set of data X:... X. Calculate the standard deviation a using the following formula:

In the formula: X; The measured values of each experiment;

X is the average value of all test results;

. Number of trials.

Step 2: Calculate the relative standard deviation of technology, and adjust the price difference based on the time standard.

For example, a certain automatic calorimeter was tested for its calibration, and ten measurements were conducted using a rate gauge

The result obtained is as follows: 264762644426512646626507

26470265265264742650442651126419.

Q-26478 Allow

relative standard deviation

The accuracy of the automatic calorimeter is 0.12K.

3. Judgment of Guess

The general instrument manual specifies the accuracy distribution, and the grain calculated should be compared with it to make a judgment. Some national standards also provide explanations for the newly developed instrument grid, for example, GB lamp 213-1996 specifies it clearly. For non classical principle designed automatic soldier thermal instruments, as long as the grid area and accuracy meet the requirements, they can be used. The standard stipulates that the relative standard deviation of the results of 5 or more benzoic acid tests should not exceed 0.20K, indicating that the testing accuracy meets the requirements. So the automatic measurement or discussion of the upper tree can meet the national standard OB light 818-1996.

2、 Accuracy testing methods

Accurate smoke level indicates the degree to which the test results are close to the true values. Good grid quality of the instrument line does not necessarily mean good accuracy, but rather the presence of a system model in the instrument. Although the calibration is good, accuracy may not necessarily be good. In the absence of systematic errors, the accuracy of the results of the instrument with good accuracy is definitely good. The accuracy of the instrument can be checked using the buried statistical method, or a column label can be used

Inspect for quasi substances or standards

1. Mathematical statistics method

This method is actually to check whether there is a significant difference between the results of repeated measurements in different measurement ranges and the standard values of the standard. The selected standard sample is tested n times using a calibration instrument to obtain