保定市分析仪厂

影响直读光谱仪分析质量的7个因素

7 factors affecting the analysis quality of a direct reading spectrometer

1、氩气

1. Argon gas

吹氩的主要作用是试样激发时赶走火花室内的空气，减小空气对紫外光区谱线的吸收。主要是因为空气中的氧气、水蒸气在远紫外区具有强烈的吸收带，对分析结果造成很大的影响，且不利于激发稳定，形成或加强扩散放电，激发时产生白点。另外，样品中的合金元素在高温情况下可能会与空气中成分发生化学反应生成分子化合物，从而会有分析光谱对我们所需的原子光谱造成干扰。因此必须要求氩气的纯度达到99.999％以上。另外，氩气的压力和流量也对分析质量有一定影响，它决定氩气对放电表面的冲击能力，这种激发能力必须适当，过低，不足以将试样激发过程中产生的氧气和它形成的氧化物冲掉，这些氧化物凝集在电极表面上，从而抑制试样的继续激发；氩气流量过大，一是造成不必要的浪费。二是对光谱仪也有一定的损伤。因此氩气压力和流量必须适当。据实践证明，氩气的压力和流量，应根据不同材质进行调节，对中低合金钢的分析，输入光谱仪的氩气压力应达到0.5—1.5MPa，动态氩的流量为12～20个读数，静态氩的流量为3～5个读数。

The main effect of argon blowing is to drive away the air in the spark chamber when the sample is excited and to reduce the absorption of ultraviolet spectrum lines by the air. The main reason is that the oxygen and water vapor in the air have a strong absorption band in the far ultraviolet region, which has a great influence on the analysis results, and is not conducive to the excitation of stability, forming or strengthening the diffusion discharge and producing white spots when excited. In addition, the alloy elements in the sample may react with the components of the air to produce molecular compounds at high temperature, and the analytical spectra will interfere with the atomic spectra we need. Therefore, the purity of argon must be above 99.999%. In addition, the pressure and flow of argon also have a certain effect on the quality of the analysis. It determines the impact of argon on the discharge surface, which must be appropriate and low enough to flush out the oxygen produced during the sample excitation and the oxide formed by it, and these oxides are agglutinated on the surface of the electrode, thus inhibiting the test. The argon flow rate is too high, which causes unnecessary waste. The two is a certain damage to the spectrometer. Therefore, the pressure and flow of argon must be appropriate. According to practice, it is proved that the pressure and flow of argon should be adjusted according to different materials. The analysis of middle and low alloy steel is that the argon pressure of the input spectrometer should reach 0.5 to 1.5MPa, the flow of dynamic argon is 12~20 readings, and the flow of static argon is 3~5 readings.

2、狭缝

2, slit

光谱仪采用了一个复杂而又敏感的光学系统。光谱仪的环境温度，湿度，机械振动，以及大气压的变化，都会使谱线产生微小的变化而造成谱线的偏移。气压和湿度变化会改变介质的折射率，从而使谱线发生偏移，湿度的提高不仅会使空气的折射率增大，而且会对光学零件产生腐蚀作用，降底了仪器透光率，湿度一般应控制在55%-60%以下。温度对光栅的影响主要改变光栅常数，使角色散率发生变化，产生谱线漂移。这些变化会使光谱线不能完全对准相应的出射狭缝，从而影响分析结果。因此光学系统每天至少调整一次，若室内温度控制恒定．即使天气变化不大，每周也要调整狭缝二次。

The spectrometer uses a complex and sensitive optical system. The environmental temperature, humidity, mechanical vibration and atmospheric pressure change of the spectrometer will cause a slight change in the spectrum and cause the deviation of the spectrum. The change of air pressure and humidity will change the refractive index of the medium and make the spectral line offset. The increase of humidity will not only increase the refractive index of the air, but also cause corrosion to the optical parts, reduce the transmittance of the instrument, and the humidity should be controlled below 55%-60%. The influence of temperature on grating mainly changes the grating constant, resulting in the change of the role dispersion, resulting in spectral line drift. These changes will make the spectral line not completely aligned to the corresponding exit slit, thus affecting the analysis results. Therefore, the optical system should be adjusted at least once a day. If the indoor temperature is kept constant, even if the weather changes little, the slit should be adjusted two times a week.

3、入射窗的透镜

3. The lens of the incident window

通向各室的透镜，特别是通向空气室的透镜，由于试样激发时吹氩，使得试样曝光时产生的灰尘被吹至透镜上而阻止了光线的透过，影响测定结果的准确性。因此要经常清洗，一般一周两次，使其保持清洁，保证所有光线通过透镜而进入光室进行测定。特别提醒的是，清洗透镜后要多激发几个废样，等强度稳定后再进行标准化操作，否则对分析质量造成影响。

The lenses that lead to the chambers, especially the lenses that lead to the air chamber, can blow the dust on the lens to prevent the transmission of the light and affect the accuracy of the results as the sample is stimulated by blowing argon. Therefore, it should be cleaned regularly, two times a week to keep it clean, and ensure that all rays pass through the lens and enter the optical chamber for determination. It is particularly reminding that after cleaning the lens, several waste samples should be excused, and then the standard operation should be carried out after the strength is stabilized, otherwise, the quality of the analysis will be affected.

4、激发台

4, excite table

清洗激发台的内表面，主要是避免残留内壁的粉尘放电影响分析结果。通常每激发100—200次应清理一次。电极与激发面之间的距离，必须按极距要求调整好，如果与激发面的距离太大，试样不易激发，如果电极与激发面的距离太小，曝光时放电电流太大，以至于与仪器各参数不相匹配，使测定结果与实际结果之间有差异，影响测定的准确性。因此必须将电极与激发面的距离调整准确，清洗激发台和电极后一定要重视这个问题。

Cleaning the internal surface of the excitation station is mainly to avoid the analysis of the dust inside the wall. Usually 100 to 200 times per excitation should be cleaned up once. The distance between the electrode and the excitation surface must be adjusted according to the requirement of the polar distance. If the distance from the excitation surface is too large, the sample is not easy to excite. If the distance between the electrode and the excitation surface is too small, the discharge current is too large to match the parameters of the instrument so that there is a difference between the result and the actual result, which affects the measurement. The accuracy of the set. Therefore, the distance between the electrode and the excitation surface must be adjusted accurately. After cleaning the excitation stage and electrode, we must pay attention to this problem.

5、工作曲线的校正

5. Correction of the working curve

光电直读光谱仪法虽然不受感光板限制，但工作曲线绘制成后，经过一段时间曲线也会变动。例如：透镜的污染、对电极的玷污、温湿度的变化、氩气的影响、电源的波动等，均能使曲线发生变化。原始曲线图中A的位置，经过一段时间后，曲线可能漂移到B的位置．为了使用曲线进行分析必须设法将曲线B恢复到曲线A的位置．为此必须对工作曲线进行标准化。在进行曲线标准化必须注意以下几点：

Although the photoelectric direct reading spectrometer is not restricted by the sensitive plate, the curve will change after a working curve is drawn. For example, lens pollution, fouling of electrodes, temperature and humidity changes, argon effects, power fluctuations and so on, all can make the curve change. In the original curve, the position of A, after a period of time, may drift to the position of B. In order to analyze the curve, we must try to restore the curve B to the position of the curve A. Therefore, the working curve must be standardized. In the standardization of curves, we must pay attention to the following points:

(1)在清洗样品激发台后必须先激发10次以上或通氩气一个小时后才能做日常标准化工作。

(1) after cleaning the sample, it must be activated more than 10 times or argon for one hour before the standardization work can be done.

(2)标准化的样品要均匀，制样要仔细，样品的表面平整，纹路清淅。分析间隙准确，样品架保持清洁。

(2) the standardized sample should be uniform, the sample should be careful, the surface of the sample should be smooth and the texture should be clear. The analysis clearance is accurate and the sample frame is kept clean.

(3)标准化频率是根据分析样品的多少来定，一般情况一天必须标准化两次。

(3) standardized frequency is determined according to the number of samples analyzed, and the general situation must be standardized two times a day.

6、控制试样

6. Control sample

在实际工作中，由于试样和标准样品的冶金过程和某些物理状态的差异，常常使工作曲线发生变化，通常标准样品多为锻造和轧制状态，而日常分析为浇铸状态。为了避免试样因冶金状态变化给分析结果带影响，常常应使用一个与分析试样冶金状态和物理状态都一样的控样，来控制分析结果，控样的元素含量应位于工作曲线含量范围内，并与分析试样的含量越接近越好。同时，控制样品的元素含量应当准确可靠，成份分布均匀，外观无气孔、砂眼、裂纹等物理缺陷。

In practical work, the working curves often change because of the metallurgical process and some physical state differences between the sample and the standard sample. Usually the standard samples are mostly forging and rolling, and the daily analysis is the casting state. In order to avoid the influence of the metallurgical state of the sample to the analysis results, a control sample which is the same as the metallurgical and physical state of the sample should be used to control the analysis results. The content of the sample should be in the content range of the working curve, and the closer the better the content of the sample is. At the same time, the element content of the control sample should be accurate and reliable, with uniform distribution of components and no physical defects such as porosity, sand holes and cracks.

7、样品

7. Sample

光谱分析结果的好坏，很大程度取决于样品，要注意样品的制备和处理技术。由于气孔偏析原因没有得到平整的表面或样品没有放置好，以及操作错误引起的误差，都会给

The quality of the spectral analysis depends largely on the samples, and the preparation and processing techniques of the samples should be paid attention to. Because of the reasons for porosity segregation, no smooth surface or sample is not placed, and errors caused by operation errors will be given.