分光不度计中杂散光的产生,危害及防护

本文分析了分光光度计中杂散光的产生和危害,并提出了具体防护方法及措施。     

检定721分光光度计杂散光问题探讨

通过对721分光光度计进行检定,讨论检定过程中遇到的杂散光问题和解决方法。     

浅析杂散光对分光光度计的影响

分光光度计是理化分析中最常用的仪器,杂散光是分光光度计检定中的一个重要指标,其大小对于分光光度计测量结果有很大的影响,决定仪器的合格与否。本人依据计量检定规程技术要求,结合实际工作出现的问题,对其进行了全面的总结和分析。     

滤色片对分光光度计杂散光的影响

杂散光是分光光度计检定中一个必检的重要指标,其大小决定仪器的合格与否.本文从理论上和实际中讨论滤色片的位置对杂散光大小的影响,为从事分光光度计检定和维修的人员提供一个参考.     

分光光度计中杂散光的产生、危害及防护

本文分析了分光光度计中杂散光的产生和危害 ,并提出了具体防护方法及措施     

紫外、可见分光光度计杂散光检定的建议

通过对现行检定规程JJG178—2007《紫外、可见、近红外分光光度计》杂散光检定方法介绍,指出并论证了因受现有杂散光标准物质的限制,其杂散光检定存在需要进一步完善之处。提出了紫外、可见分光光度计杂散光检定的建议.     

探讨钼锑抗分光光度法测定磷酸盐的最佳显色时间

本文利用722型分光光度计测定磷酸盐标准使用液经显色后吸光度随时间的变化，探讨钼锑抗分光光度法测定水中磷酸盐的最佳分光时间。     

杂散光对分光光度计测量结果的影响探讨

杂散光是分光光度计检定中一个必检的重要指标,其大小决定仪器的合格与否,而且,杂散光的偏差对于分光光度计测量结果有很大的影响。本人结合实际工作对杂散光的来源、杂散光对分光光度计测量结果的影响、杂散光的检测、如何减小杂散光对分光光度计测量结果的影响等方面进行了分析。     

杂散光对紫外、可见分光光度计测量结果的影响及检定方法

影响紫外、可见分光光度计测量误差的因素很多,杂散光是误差主要来源之一。本文分析杂散光对该仪器测量结果准确性的影响,介绍杂散光的检定方法,以及减小杂散光的措施。     

试谈《计量标准考核规范》实施要点

依照《计量标准考核规范》的原则要求的4大项14个小项,根据忠于规范,便于操作,易于掌握的原则,逐项制定出实施要点,以增加透明度和考评员及计量人员的可操作性。     

Simple spectral stray light correction method for array spectroradiometers

A simple, practical method has been developed to correct a spectroradiometer's response for measurement errors arising from the instrument's spectral stray light. By characterizing the instrument's response to a set of monochromatic laser sources that cover the instrument's spectral range, one obtains a spectral stray light signal distribution matrix that quantifies the magnitude of the spectral stray light signal within the instrument. By use of these data, a spectral stray light correction matrix is derived and the instrument's response can be corrected with a simple matrix multiplication. The method has been implemented and validated with a commercial CCD-array spectrograph. Spectral stray light errors after the correction was applied were reduced by 1-2 orders of magnitude to a level of approximately 10(-5) for a broadband source measurement, equivalent to less than one count of the 15-bit-resolution instrument. This method is fast enough to be integrated into an instrument's software to perform real-time corrections with minimal effect on acquisition speed. Using instruments that have been corrected for spectral stray light, we expect significant reductions in overall measurement uncertainties in many applications in which spectrometers are commonly used, including radiometry, colorimetry, photometry, and biotechnology.     

Determination of stray light at the PTB goniophotometer facility

For improved luminous flux measurements, the Physikalisch-Technische Bundesanstalt (PTB) was equipped with a new robotic goniophotometer. In order to characterize this instrument, to reduce the combined measurement uncertainty, and to determine the respective uncertainty components, the influence of stray light on the measurement results was investigated. Considering the specific structure of the robotic goniophotometer, stray light was measured on-line by means of a purpose-built “back-looking” photometer. By this means, the influence of the luminous intensity distribution of each individual light source with regard to its stray light could be considered. Before the first experimental application, the invented procedure was tested by means of calculations using mathematical models. In this paper, the mathematical model for the calculation of stray light in the goniophotometer room is presented together with the calculation results and the results of the first measurements. The achieved results indicate that the recommended stray light measurements can decrease the total relative standard measurement uncertainty of luminous flux measurements down to 2 × 10⁻³.     

Longitudinal recording in a stray field

We have studied the sensitivity of soft error rate (SER) to an external magnetic field in longitudinal hard disk drives. We found that during writing SER is generally quadratic with field amplitude and symmetric with field direction. The application of an external field during writing also shifts the center of the track. In contrast, during reading SER is predominantly linear with field amplitude and antisymmetric with field direction. There is no shift in the track center when the field is applied during reading up to 100 Oe. We explain the difference in the track center shift between writing and reading in terms of the effect of the stray field on the servo positioning system.     

Ultraviolet-absorption photometer for measurement of ozone on a rocket-boosted payload

We developed a rocket payload to perform in situ measurements of atmospheric ozone at the University of Houston. The ozone detector is a dual-beam UV-absorption photometer that uses the 253.7-nm radiation from a low-pressure mercury-vapor lamp to illuminate two identical absorption chambers. We describe the design features and the operation of the instrument. The fundamental resolution of the photometer is shown to be 2.7 × 10(15) molecules m(-3). We present the ozone profile measured during parachute descent following boosted ascent to 60 km by a Nike-Orion rocket. The uncertainty in the measurement of this ozone profile is estimated to be 8.2%.     

NO(2) photometer Based on Solid-State Light Sources

A sensitive NO(2) analyzer, that uses a commercial LED emitting near 450 nm, has been developed. The prototype can measure NO(2) concentrations as low as 1 part in 10(9) as defined by the Environmental Protection Agency. The response time of the system is 1 min. In addition, a demonstration of the use of external-cavity frequency-doubled diode laser radiation to accomplish similar measurements is reported. However, because of low nonlinear optical conversion efficiencies, comparable detection limits were not possible. Nonetheless, frequency-doubled diode-laser wavelengths have the potential to reach farther into the UV than LED technology, allowing the detection and measurement of numerous other gaseous species of interest.