高分子薄膜电容式湿敏元件研制成功

由国家气象局气象科学研究院大气探测所丁碧君等同志研制的高分子薄膜电容式湿敏元件,于1987年10月30日在北京召开的鉴定会上通过了科研成果鉴定。会议由国家气象局科教司主持,鉴定组由局内外专家10人组成,易仕明任组长,刘余滨、许梓秀任付组长。参加会议的有局科教司、业务发展司、仪器设备司、气象科学研究院及航天部5院501设计部等单位的有关专家与代表共27人。 会议听取了大气探测所的研制工作报告、试验报告、鉴定测试组的测试报告以及用户的使用报告。并参观了研制的元件和现场试验样机。 自1982年开展研制工作以来,该元件先后经气象台站及航天部等单位的实际考验及性能测试,证实其技术性能指标已达到了芬兰和美国同类产品的     

碳湿敏元件及其基测装置

本文着重介绍探空仪用碳湿敏元件的基测装置——氯化镁(MgCl_2)饱和盐密封容器的结构、原理及其使用方法。     

L波段碳湿敏元件特性试验

目前国内大部分探空站已经启用新一代探空仪——上海长望气象科技有限公司生产的L波段电子探空仪。新探空仪的数据率、测量准确度和可靠性都有较大的提高。新探空仪使用的湿度敏感元件是碳湿敏电阻。我们利用工厂添置的能测到-30℃低温的高精度湿度校准设备，进行了大量静态测试，进一步验证了碳湿敏元件与老探空仪使用的肠衣敏感元件相比，灵敏度高，滞后小，在高空低温期间感应陕，测量准确度有较大提高。     

肠衣湿敏元件校准曲线的回归初探

一、引言 用微机代替人工进行GZZ2型探空仪的相对湿度校准曲线的点绘工作有很多优点。首先将能极大地减小人工点绘和台站再校准的工作误差,并减小用固定的曲线尺在绘制大同小异各式各样曲线时所带来的模式误差,最终将提高探空仪探测数据的准确性。其次将能使台站得到规范化和数字化的标准曲线,也不必再人工取点,使用极为方便。此外还可减轻校准工人的劳动强度和提高劳动生产率。     

GTS探空仪碳湿敏元件性能测试数据分析及相对湿度订正

碳湿敏元件受温度影响明显,造成相对湿度探空数据测量的误差。利用温湿控制设备对该元件进行静态试验,测试不同温度对元件感湿特性的影响。通过对试验数据分析计算得到元件的相对湿度温度项订正数据,以及相对湿度的温度项订正拟合公式,可以有效订正由温度引起的相对湿度探空数据误差。对实际相对湿度探空数据资料订正效果的对比分析表明,经过温度项订正后的相对湿度探空数据,不但其准确度得到了提高,而且清楚地体现出在订正之前所不能体现的高空大气相对湿度在低湿段的变化细节。     

金属氧化物烧结体感湿元件

这里介绍的是一种以金属氧化物为主要成份的烧结体氧化物合成半导体感湿元件(以下简称烧结体感湿元件)。由于这种感湿元件的戍份和所具有的微细结构的特点,使得共温度系数和固有的电阻值都小,对湿度的电阻变化显著,而且不受外部温度变化的影响。下面准备从该元件的组成、制做工艺及测湿原理三个方面介绍。一、烧结体感湿元件的组成这种烧结体氧化物合成半导体感湿元件的成份见表1。     

美国 PCRC 电湿感应元件

PCRC 电湿感应元件是美国理化研究公司1975年生产的电子湿度计的电路元件。一、原理、特点PCRC 电湿感应元件是通过电阻的变化来感应相对湿度的变化。它是一个经过化学处理的苯乙烯塑料薄膜,它的表面层是导电的,此表面层与不导电的基底结成一体。相对湿度的变化引起表面电阻率的改变。由于不用表面涂层或乳胶以及这种特殊的苯乙烯具有的高的温度特性,使得感应元件能应付恶劣的环境。感应元件的湿度感应部分限制在表面上,采用表面吸附方法来吸收或放出水分,这使得它能迅速地响应相对湿度的变化。     

新型湿敏传感器的测试

本文讨论了正在开发中的耐水性高分子新型湿敏传感器的长期稳定性、初步证明这种传感器具有实用前景，所得结论对今后设计实用电路具有一定的指导意义。     

旋转式风敏元件的静特性

目前广泛使用的风敏元件,绝大多数仍然是风杯式叶轮和螺旋桨叶轮。因此,本文仅就风杯和螺旋桨的静特性做些介绍。 一、风杯的静特性 图1为四杯式叶轮在速度为V的气流中的瞬间位置示意图。为了便于讨论和计算,设杯子中心旋转的线速度为v=ωr,其中r为杯子中心的旋转半径,ω为角速度。杯子跟气流的相互作用,和一个其方向与矢量ωr方向相反的气流的作用是等价的。相对速度U,是矢量V和-v的几何和,即     

旋转式风敏元件的动特性

一、前言 在不稳定的气流中,旋转式风敏元件的工作情况,可以用它们的动特性来表征。这一特性决定着叶轮对气流速度任何变化的反应,以及风速瞬时值和平均值的测量误差。就其动特性来说,风杯式和螺旋桨式叶轮属于非周期性环节,即一阶动力学系统,其反应仅仅取决于输入信号(风速)的形式和输出信号(仪表示值)的一次导数。 从数学上说,一阶动力学系统可以用一阶微分方程式来描述     

Humidity fluctuations in the marine boundary layer measured at a coastal site with an infrared humidity sensor

An extensive set of humidity turbulence data has been analyzed from 22-m height in the marine boundary layer. Fluctuations of humidity were measured by an OPHIR, an infrared humidity sensor with a 10 Hz scanning frequency and humidity spectra were produced. The shapes of the normalized spectra follow the established similarity functions. However the 10-min time averaged measurements underestimate the value of the absolute humidity. The importance of the humidity flux contribution in a marine environment in calculating the Obukhov stability length has been studied. Deviations from Monin-Obukhov similarity theory seem to be connected to a low correlation between humidity and temperature.     

我国探空测湿传感器的温、湿特性试验与分析

通过改进湿度传感器温湿特性实验室测试方法,对国产GPS探空系统和RS92探空仪湿度传感器的温湿特性进行了测试分析.结果表明:国产电子探空仪的湿度传感器在低温状态下探测滞后性明显,给高空湿度的动态测量带来了较大误差,尤其是在低温升湿过程测量比低温降湿过程更为显著.试验还表明环境空气流量的变化会对湿度的测量造成明显的影响,结果有助于改进探空仪湿度传感器测湿算法和防雨帽工艺设计,提高高空湿度测量能力.     

黑龙江省地市级气象观测站湿度传感器现场核查及调整

1核查步骤湿度传感器的核查包括两部分,第一部分是外观检查,主要检查传感器外型结构是否完好,表面是否有明显的凹迹、外伤、裂缝、变形等现象,表面涂层有无起泡、龟裂和脱落,金属件有无严重锈蚀及其它机械损伤,传感器是否有型号、出厂编号等明显标志。对出现以上状况的传感器要直接更换。对于使用过的湿度传感器,重点检查过滤膜保护层是否有污染现象。若污染严重应更换新的过滤膜。第二部分是示值误差核查,经过外观检查合格的湿度传感器,才能进行示值误差的核查。下文重点说明示值误差核查的步骤。     

A study on observed evolution of boundary layer humidity distributions

Data are used from the Met Office tethered balloon facility to examine the evolution of boundary layer humidity probability density functions during various meteorological conditions. Results typically show significant changes in all four moments (mean, standard deviation, skewness and kurtosis) over periods from one to several hours. Boundary layers experiencing the greatest changes were normally convective in nature. In contrast, a quiescent wintertime boundary layer was seen to show very little evolution over a period of two days. Models which use statistical distributions of humidity for cloud prediction should ideally be able to reproduce these observations.     

一种新的温度传感器湿度补偿方法

针对温度传感器测量中易受湿度影响的问题,通过对思维进化算法（Mind Evolutionary Algorithm,MEA）中的趋同操作、异化操作及收敛条件进行研究改进,对趋同操作中的散布权值进行自适应调整,在异化操作中引入差分进化算法的变异操作,并考虑收敛条件中搜索平面平缓的情况,提出了基于改进思维进化算法的BP神经网络湿度补偿方法.由湿度影响检定实验得到的样本数据,利用此补偿方法建立湿度补偿模型,将补偿结果与未经优化的BP神经网络模型的结果进行比较研究.结果表明,基于改进思维进化算法的BP神经网络模型补偿精度较高,收敛速度快,计算量小,可有效提高温度传感器的测量精度和可靠性,便于实际应用.     

Temperature and humidity spectra in the atmospheric surface layer

Temperature and humidity spectra have been measured at 3 and 12 m above the ground, together with profiles of wind, temperature and humidity, and flux measurements. Both temperature and humidity spectra appear to follow Monin-Obukov similarity as well as Kolmogorov's prediction for the inertial subrange. The standard deviations of temperature and humidity fluctuations support Monin-Obukov similarity and the predictions of local free convection. The spectral constants for the inertial subrange have been estimated as 0.8 for temperature and 0.6 for humidity.     

Temperature and humidity structure of the sub-cloud layer over land

Observations of temperature, pressure and humidity have been made from an aircraft beneath cumulus clouds which formed over extensive flat country. In fair weather over land, cumulus cloud base is generally above the average top of the well-mixed convection layer so that penetrative convection is necessary to initiate cloud formation. The convective layer does not evolve and deepen uniformly over large areas (say greater than 100-km radius). Rather, it develops a patchy structure at 1–10 km scales. Such patches, close beneath cloud base, have thermodynamic properties very like those of the convection layer and in such regions that layer effectively extends right up to cloud base. Meso-scale effects (e.g., 50 km) seem to be important in determining where clear and cloudy areas occur, and although it appears reasonable to attribute this to local dynamic effects (e.g., subsidence), it is not possible to eliminate other possibilities on the basis of the present data.     

Correlated humidity and temperature measurements in the urban atmospheric boundary layer

Summary To investigate the effect of atmospheric turbulence on microwave communication links, temperature and water vapor pressure have been measured and radio refractivity has been computed, during different meteorological conditions, in the atmospheric boundary layer of an urban site. The cospectra between temperature (T) and water vapor pressure (e) have been found to be either negative over the whole range of frequencies, or the low-frequency end of the cospectrum is of opposite sign relative to higher frequency end. In both cases cospectra follow a–5/3 law in the inertial subrange, in agreement with the theoretical predictions. The coherence spectra clearly show that the temperature and humidity fluctuations are highly coherent within the inertial subrange under both convective and stable conditions. The relative contribution ofC _T ² ,C _eT andC _e ² to the real refractive index structure parameterC _n ² is examined and discussed.With 4 Figures     

边界层参数化方案对暴雨数值模拟的影响

大气边界层(Atmospheric Boundary Layer,ABL)是自由大气和地球表面(陆地和海洋)的连接层,它对于降水的发生发展有重要影响。ABL高度是ABL的一个重要参数,主要应用于大气数值天气(或气候)模式中的ABL过程的参数化,获取准确的ABL高度数据对于提高数值天气预报模式、空气污染物预报模式等的预报精度具有重要作用。概述了利用常规探空资料、卫星遥感资料、气溶胶后向散射资料、全球导航卫星系统GNSS (Global Navigation Satellite System)掩星探测资料等数据估计ABL高度的主要方法及进展情况,提出在同时具有多种观测资料时如何处理ABL高度的三个基本原则,并以目前广泛应用的数值天气预报模式WRF (Weather Research and Forecasting)为例重点介绍ABL高度数据在数值天气(或气候)预报模式中的应用,对相关的发展情况进行了总结展望。

     

The extent of the unstable Monin-Obukhov layer for temperature and humidity above complex hilly grassland

Potential temperature, specific humidity and wind profiles measured by radiosondes under unstable but windy conditions during FIFE in northeastern Kansas were analyzed within the framework of Monin-Obukhov similarity. Around 86% of these profiles were found to have a height range over which the similarity, formulated in terms of the Businger-Dyer functions, is valid and for which the resulting surface fluxes are in good agreement with independent measurements at ground stations. When scaled with the surface roughness z ₀ = 1.05 m and the displacement height d ₀ = 26.9 m, for the potential temperature this height range was 45 (±31) (z – d ₀ )/z ₀ 104 (±54) and the comparison of the profile-derived surface fluxes with the independent measurements gave a correlation coefficient of r = 0.96. For the specific humidity these values are 42 (±29) (z – d ₀ )/z ₀ 96 (±38) and r = 0.94. In terms of the height of the bottom of the inversion H _i , in the morning hours the upper limit of (z – d ₀ ) in the Monin-Obukhov layer is approximately 0.3H _i , whereas for a fully developed ABL it is closer to 0.1H _i . Probably, as a result of the short sampling times and perhaps also of the small gradients under the windy conditions, the exact height range of validity was difficult to establish from a mere inspection of these profiles.