Reasons for Deviation of Data Analysis of Carbon & Sulfur Analyzer
Carbon & Sulfur Analyzer is a special instrument for analyzing carbon and sulfur. It can get more accurate results through the analysis of combustion aid. However, some operational rasons may cause large deviations in the analyzed data. Let us look at what these factory are.
1. Weighing Standard Sample
If the sample is weighed differently, there is a difference in the quality of C and S contained in it, resulting in a difference in the area where the analysis result falls on the calibration curve of the instrument. This results in fluctuations in analytical results, especially around the upper and lower limits of the analytical instrument. The theoriectical basis of infrared analysis is the Lambert-Bill law, so the calibration curve usually shows an “S” shape, with the lower and upper ends of the curve deviating from the linear range indicated by the dashed line. In the case of a low-content sample(the lower end of the curve), when the sample is weighed at a higher weight, the corresponding point of absolute mass obtained is Ca. When the sample is weighed foe the weight comparison, the corresponding point for the absolute mass is Cb, which deviates from the linear relationship indicated by the dashed line, and therefore the result for the content is higher.
For high content samples, the opposite is true and lower analytical results will be obtained. In addition, different sample weights have a direct impact on high frequency induction combustion. The combustion temperature and condition of the carbon and sulfur meter are not only related to the power of the furnace design itself, but also to the amount of magnetically conductive material in the induction zone. The combustion teperature is not continuously constant, and as the substance melts and burns, the amount of induction gradually decreases.
2. Appropriate Sample Quality
For example, when analyzing some refractory substances(such as ferrosilicon), where a constant weight of flux is added and a constant amount of heat is generated, too much sample will result in incomplete combustion of the sample and incomplete release of carbon and sulfur from the sample.
3. Amount of Flux Added
Another factor that affects the stability of the analysis is the amount of flux added, whcih is significant when analyzing low content samples.
For example, when analyzing a sample with carbon and sulfur content less than 15ppm, add 1500mg of flux and 2000mg of flux respectively(C≤8ppm and S≤5ppm of carbon and sulfur in the flux). Since the amount of flux added is not involved in the calculation of the analytical results, a fluctuation in the amount of carbon and sulfur contained in 500mg of flux was introduced between the two analyses.
Assuming that the carbon and sulfur content in the flux is 3ppm and the sample is weighed at 500mg, a deviation of 3ppm is introduced due to the weight of the flux added.