Spark direct-reading spectrometer is
a high-precision instrument. In the actual operation, several points should be paid attention to, to avoid incorrect operation, which will cause errors in the analysis results, and even fail to test the results. .
1. Sample excitation and computer operation.
① For the sake of safety, the operation of the computer and the excitation sample must be operated by one person to the end.
② After the sample is placed, the computer's operation instructions can be used to excite the sample.
③ Pay attention to three points when stimulating post operation. The first point is to listen to the sound. The sample is not placed well. When there is a leak, the excitation sound is abnormal. The second point is to check the spot of the excitation discharge. The condensation discharge is good and the diffusion discharge (white point) is not good. The third point is to check whether there are micro cracks, pores and trachoma at the location of the excitation points, and whether the excitation points overlap, etc., and provide an important reference for data processing.
④ Each sample must be excited more than twice.
⑤ When operating the computer, record the furnace number, frequency and steel type, and record the name of the operator.
2. Data processing operations.
① The analysis data shall be based on the content of the standard steel, and shall be subject to the control of the positive and negative deviations of the standard steel.
② The selection and selection of data must be stable, and many factors must be considered, such as changes in iron value, changes in other elements, the amount of aluminum inserted, excitation spots, excitation sound, etc. Sometimes it is necessary to regrind the sample analysis and verification, sometimes Multiple firings are required to verify. At the time of verifying the analysis sample, it is also necessary to excite the standard steel with a close content to prove that the instrument
is in a normal working state.
③ If the standard steel addition and subtraction amount is too large, it must be standardized to correct the working curve of each element.
④ Pay attention to the positive and negative signs when processing data. Do not add or subtract errors or misread decimal points.
3. Standardized operation and trace operation of working curve.
① Standardized operation is performed once per shift. If the operator believes that the results of the stimulated standard steel analysis are stable, the standardized data from the previous shift can be used. When individual elements deviate too much during the analysis, standardization can be implemented to ensure the accuracy of the analysis results.
② During standard operation, it is best to use a new grinding wheel for grinding the standardized samples.
③ During the standardization process, check the number of the standardized sample and enter it as required. Do not enter carelessly.
④ After the standardization operation is completed, the coefficients and compensation values should be checked, and compared with the previous time, do not change too much.
4. Control the use of samples.
① The samples in the analysis furnace should use the same steel type as possible, and the control standard samples close to the content should be used.
② It is difficult for a control sample to meet the requirements of multi-element analysis, and try to make the content of the analysis sample close to the composition of the control standard steel.
③ In special cases, when individual elements are close to the edge specifications or exceed the standard requirements, an appropriate amount of standard steel should be selected for control.
④ The electric furnace should be contacted at any time to obtain the control standard steel in the spectrum. For rapid analysis in the furnace, it is better to use the pouring control standard steel.
⑤ For the finished sample, pay attention to the state of the sample (referring to the quenched and annealed state) and select an appropriate control standard steel.
5. Use of argon.
① Before changing the argon gas, let the gas in the bottle be empty for a while, so that the soil contaminated by the bottle mouth is blown clean.
② Before connecting the argon gas meter, test whether the bottle mouth is leaking. If the leak is found, replace it with another bottle. If there is no gas leak, fasten the meter head to the argon bottle. Slowly open the primary pressure valve on the bottle to gradually increase the pointer of the primary pressure gauge, and then slowly adjust the pressure of the secondary gauge head to rise to the specified reading: 0.15MPa gas source can be used (depending on different brands of instruments), and Regulation: Normal standby state: flow rate is 0.1-0.5L / min, large flow flushing before excitation is 5-8L / min, excitation flow rate is 3-5L / min
③ After each new argon exchange, the working curve must be re-standardized.
④ When the pressure in the bottle drops to 15 atm, new argon gas needs to be replaced; if the excited spots are found to be white spots during the work, another bottle of argon gas should also be replaced.