High frequency infrared carbon* analyzer selection method

How to choose a cost-effective instrument that meets the requirements of users. At present, there are many types of high-frequency infrared carbon-sulfur analyzers on the market. The high-frequency infrared carbon-sulfur analyzer is an advanced analytical device capable of rapidly determining carbon content and sulfur content. This article will be discussed in four aspects. After more than two decades of development, high-frequency infrared carbon-sulfur analyzer technology has matured. China began importing high-frequency infrared carbon-sulfur analyzers in the late 1970s.

Applicable principles of optional instruments:

Do not cause unnecessary waste. Therefore, it is recommended that users should make inspections before buying equipment, and do not make the purchased instruments unable to meet their own needs in order to save costs. Targeting high-end, middle- and low-end instruments has the current market carbon There are many brands of sulfur instruments and users should follow the applicable principles when purchasing carbon and sulfur instruments.

What oxygen oxygen method is selected:

The conversion of sulphur to CO2 and SO2 gas: then the combustion of carbon-sulfur analyzer is extremely important. The analysis principle of high-frequency infrared carbon-sulfur analyzer is to make carbon through high-frequency induction combustion: here, the important thing is to control the oxygen method to ensure two points. (Oxygen effect: Oxygen acts as the auxiliary gas during the entire analysis process. The concentration of CO2 and SO2 gas is used to detect the concentration of the infrared light, and the carrier gas is used).

1, to ensure that the sample when the combustion of oxygen is fully supplied, so that the sample of carbon and sulfur can be effectively converted to CO2 and SO2 gas.

2, accurate flow control to ensure the accuracy of the test.

The basis for the determination of sample data:

Three aspects of accuracy as the basis for the determination, the determination of sample data can be from the stability and accuracy of the instrument.

Instrument stability:

Instrument stability, long-term stability is the most effective basis for testing the instrument.

The method is to select 7 samples of the same kind of sample for continuous measurement and calculate according to the formula. Therefore, it can only reflect the stability of the instrument at one moment. Usually the instrument can satisfy C≤0.5%, S≤1.5%.(C:0.1%- 1%, S: 0.01%-0.1%). The criterion for determining the stability is based on the relative standard deviation (RSD) because it is a continuous measurement data. One day or one week or even one month. The basis of long-term stability is the quality of reproducibility. The long-term stability reflects the overall performance of the instrument. Reproducibility refers to the data of the same sample measured at different time periods. Good or bad, usually the stability of a good instrument can at least do one day data changes will not be bad, this time period may be an hour.

Instrument accuracy:

If the linearity is not allowed, the measured sample value must be inaccurate. Calibrate the instrument with a high content of the calibration steel. The linearity will directly affect the accuracy of the analysis. The linear concept refers to the instrument manufacturer's data when it leaves the factory. Calibration. Corresponding low-level steel measurement values ​​should be within the allowable error range, usually from low to high in the measurement range, smoothed by a formula into a straight line, the accuracy of the instrument is usually judged by the linearity, high frequency Infrared carbon-sulfur analyzer uses the reference statutory value. The linear reference function, the determination of the good or bad can be taken within the measurement range, optionally with several different content of standard steel.

Instrument accuracy:

The user needs to understand that the sensitivity of the detector and the accuracy of the instrument are different concepts. There are usually two ways to calibrate the instrument, but this accuracy is not suitable for routine analysis. The accuracy of the instrument is usually the focus of the manufacturer's publicity, usually the detector The sensitivity is very high, but the accuracy of the instrument is also affected by other factors, the use of gas calibration instruments usually advertised with higher accuracy, the use of solid calibration instruments usually advertised with relatively low accuracy, but more solid instrument calibration Suitable for daily use by users, one is gas calibration, and the other is solid calibration.

Pay attention to the reliability of the instrument:

The other indicators of the instrument are not talked about. Accuracy refers to the performance of the instrument's analytical data. The instrument's reliability index is a very important indicator in the actual application of the instrument. Reliability in the daily use of the instrument The aspect is very important, accuracy, stability, accuracy, accuracy, etc. are the branches of the instrument, and reliability is an important indicator to measure the failure rate of the instrument. If the reliability of the instrument is not good, if the stability is, then the reliability is the instrument. The foundation.