计量检测设备的采购控制

文章论述了计量检测设备采购的闭环控制方法，以期提高采购工作质量，保证合格的计量检测设备进入企业生产经营环节。     

Improving the accuracy of measuring the passband of spatial frequency channels in the visual system

We propose a method for measuring the passband of spatial frequency channels in the visual system (in hertz) by measuring the flicker period followed by calculating the frequency. We present the results of our experimental studies.     

Method of calculating low-frequency noise in measuring apparatus with a correction

Translated from Izmeritel'naya Tekhnika, No. 7, pp. 41–43, July, 1988.     

Instrument for receiving automatically precise-time radio signals

Conclusions The device for the automatic locking-in of precise time signals uses a method based on a new principle for fixing these signals by their coincidence area with a rectangular gating pulse. The advantages of this method of forming input pulses in the automatic device as compared with recording the time signal at a given level of its leading edge has been shown [3].     

An apparatus for measuring infra-low-frequency noise

Conclusion Using the apparatus developed by the authors, a series of measurements was carried out of the noise factor of prototypes of MOS transistors with an induced p-channel which were fabricated in the technological laboratory of the microelectronics chair of the Moscow Engineering Physics Institute.The apparatus described allows measurement of the spectral density of the noise (or the noise factor) by the comparison method in the frequency range from 0.1 to 100 Hz. The effective filter passband varies in the range from 10 to 100% of the resonant frequency. The sensitivity of the apparatus was determined by the sensitivity of the broadband amplifier used, and in our experiments it was 0.1V²/Hz.The measurement error, which is determined by the error of each of the blocks of the apparatus, does not exceed 15%.Translated from Izmeritel'naya Tekhnika, No. 8, pp. 74–76, August, 1970.     

热探针测定装置参数实验研究

针对线热源理论自制的热探针在实际测定导热系数过程中所得结果受实验参数影响显著的问题,该文对加热时间、电压、试样直径3个实验参数展开研究,在不同的装置参数下测定乙二醇的导热系数,以探究三者对导热系数测定结果的影响及参数选取的最优区间。实验结果表明:热探针的最佳加热时间为40~60 s,最佳电压为1~2 V;电压2 V时可忽略试样直径对测定结果的影响;实验过程温度变化5℃时可显著降低试样对流引起的实验误差。研究结果可为热探针测定导热系数参数的选取提供可靠的数据参考,所得规律能有效降低热探针测定导热系数的误差。