电性能核查校准对FDR自动土壤水分观测仪观测结果的影响研究

FDR(Frequency Domain Reflection)自动土壤水分观测仪是基于土壤中水分变化时介电常数随之改变的特性,通过LC振荡电路频率响应变化,利用土壤水分频率关系模型计算输出土壤体积含水量。随着观测仪使用时间的增长,传感器的电气性能会发生变化。因此,要保证传感器测量的准确度,使用一段时间后就要对传感器进行核查校准,将不合格的传感器进行更换。本文研究分析了以两年为周期FDR自动土壤水分观测仪电性能核查校准前后观测数据。通过分析结果得出:核查校准后观测数据准确性提高了0. 05%,因此,对自动土壤观测仪进行电性能核查是必要的。     

赋值传感器的研制

文章介绍了以铂电阻、K型热电偶、S型热电偶、C型热电偶、湿敏电容为感应元件的赋值传感器。赋值传感器具有自校准、高精度、通用性、互换性特点。校准的数字传感器是将放大器、AD转换、通讯做成集成模块,集成模块和不同感应器配套连接就成为相应的数字传感器。目前铂电阻传感器在(-200～300)℃测温精度为±0. 1℃,热电偶在(0～1500)℃测温精度为±0. 01t℃,湿敏电容型传感器在(10～99)%RH精度为±1. 5%RH。     

现场校准用的测温传感器

介绍了一种新型的现场校准用测温传感器,从温度计的结构和电阻- 温度系数计算方法方面进行论述,并提供相应的试验数据.对温度计的稳定性等方面进行分析,显示该测温传感器的优点,可用于温度产品的现场校准,具有一定的实用价值.     

功率传感器自动校准系统数据库的设计与实现

为了实现对功率传感器自动校准系统中校准数据的存储、查询等功能,设计并实现了一套嵌入在功率传感器自动校准系统中的数据库管理系统。本系统采用模块化设计思想,具有占用系统资源少、运行速度快等优点。经过测试,所设计的数据库管理系统能够满足功率传感器自动校准系统工作的需要。     

微波功率传感器自动校准系统软件的设计与开发

为实现微波功率传感器的自动校准,通过对SYSTEMⅡ功率传递系统原理和构造的分析研究,采用Visual Basic6．0开发了一套自动校准软件,重点从功能设计、数据库设计、仪器控制和校准流程设计等四个方面描述了软件的开发内容。软件可用于目前市场上多型功率传感器的自动校准,具备校准流程实时控制、数据管理、不确定度分析、标准维护、统计查询和报表输出等功能,大幅提高了功率校准的速度和工作效率。     

自动气象站风速传感器校准点线性研究

风速传感器的计量检定可以保证自动气象站风速观测数据的准确可靠。本论文针对30m/s风洞无法实现高风速段校准测试的问题,提出了一种风速传感器校准点线性扩展方案。通过大量实验数据分析得到,自动气象站风速传感器的校准点具有良好的线性特性,根据(2~30)m/s风速校准数据,可以通过线性方程将校准点延伸到60m/s,为30m/s风洞实现高风速段校准测试提供了一种合理可行的解决方案。     

自动气象站风向传感器校准结果不确定度评定

本文依据JJF 1059. 1-2012《测量不确定度评定与表示》及JJG (气象) 004-2011《自动气象站风向风速传感器检定规程》的要求,对自动气象站风向传感器校准结果的测量不确定度评定,目的是确保自动气象站风向传感器观测数据的准确、可靠。     

加速度测试系统的校准研究

传感器的性能指标如灵敏度、线性范围、频率响应特性等,对测量数据的精度和可靠性直接产生影响.因此,为了保证结果的正确性和统一性,必须定期对传感器进行校准.常用的校准方法有振动法校准、相对法校准等,本文主要利用相对校准法对所设计的加速度测试仪进行了校准,并且实际测试了几组数据,通过校准,取得了良好的效果.     

用于环氧树脂固化监测的自参考型光纤固化传感器

研究了一种新型的自参考型光纤固化传感器,用于环氧树脂固化过程的实时监测。用光纤芯折射率为1.558的多模光纤制成端面反射型折射率传感器,利用环氧树脂的折射率与固化度之间的对应关系,通过实时测量环氧树脂的折射率进行固化监测。在固化过程中,当环氧树脂的折射率变化到与光纤芯的折射率相等时,传感界面的反射信号为零,传感器可对零点偏置和灵敏系数进行校准,在此后的固化过程中,传感器能够定量地测量环氧树脂的固化度。在用多个传感器对树脂内不同部位的固化过程同时进行监测的场合,各传感器经实时自参考校准后,可根据各自的灵敏系数对输出信号统一定标,从而可以相互比较,实时地反映不同部位的固化反应过程之间的差异。      

液氧煤油发动机地面试验低温压力传感器校准系统设计

为获得不同环境温度下低温压力传感器的校准系数,提高压力测量的精度,着重介绍低温压力传感器校准系统设计,该校准系统具备温度自适应调整功能,为低温压力传感器校准提供温区连续、大范围温度可控的温度环境以及稳定可调的压力源,在一定程度上消除温度环境因素对传感器灵敏度的影响。通过低温压力传感器现场校准测试,获得压力传感器在不同温度环境下的工作特性并掌握其随温度变化的规律。     

Study on the method of precision adjustment of star sensor

Star sensors are indispensable spatial measurement sensors for high-resolution earth observation and astronomical observations, and the demand for high measurement accuracy of satellite sensors continues to increase; thus, the star sensor optical machine adjustment error cannot be ignored. The commonly used installation error correction method cannot solely meet the precision analysis requirements. In this paper, the relationship between the optical machine installation and the star sensor measurement error is analyzed, and several common adjustment error correction methods are compared. An adjustment method for optical machines is proposed to meet the requirements of very high precision star sensors. The assembly precision requirements of the investigated very high precision star sensor are analyzed considering the whole machine, and then the optical components are controlled through optical precision adjustments to satisfy the precision requirements. Finally, through the complete machine calibration, the star sensor precision adjustment for an optical machine structure is verified. This method meets the requirements of very high precision sensors and is suitable for the precision adjustment of optical machine structures, which is of practical significance to improve the precision of star sensors.     

基于雷诺准则的测温偏差压力工况修正方法

提出了一种温度传感器测温偏差校准结果的压力工况修正方法,并以某裸露式温度传感器为例,进行了测温偏差的压力工况修正。根据雷诺准则,通过改变马赫数的方式来替代压力的改变,对测温偏差的计算修正结果进行了验证。结果表明,计算修正结果与试验数据比较接近,所提出的压力工况修正方法,可以为常压条件下该型温度传感器的测温偏差校准结果提供修正的依据,同时也为其它类型温度传感器的压力工况修正提供了参考。     

脉冲磁场传感器的时域标定

针对脉冲磁场测量的要求，对传感器的时域标定问题进行了研究，组建基于高压脉冲源，ＴＥＭ传输室，数字存贮示波器及计算机的时域标定系统，提出了基于输出误差模型的时域定数据处理方法，利用该模型可方便地获得的传感器的灵敏度，转折频率等参数，成功地利用所建立的误差修正模型对传感器造成的测量失真进行了恢复。     

A general method for calculating the uncertainty of virtual sensors for packaged air conditioners

Virtual sensors use data from low-cost measurements and calibrated models to provide outputs that would either be too expensive or impossible to measure directly. Virtual sensor technology has the potential to enable cost-effective implementation of advanced monitoring, diagnostic, and/or control features for buildings. While it is commonly known that the reliability of virtual sensors depends on the amount and conditions of calibration data, no methods have been presented that quantify the effect of the conditions of calibration data on virtual sensor output uncertainty. In this paper, a general method is presented for estimating the virtual sensor output uncertainty in terms of the uncertainty, conditions and amount of calibration data. The method is demonstrated with a power consumption virtual sensor for packaged air conditioning systems.     

温度传感器辐射修正校准的准确牲研究

为了确定温度传感器辐射修正校准的准确性,需要对温度传感器辐射修正校准结果进行对比及不确定度分析.本文介绍了在热校准风洞中进行温度传感器辐射修正校准的结果,并做了对比研究和不确定度分析.     

Sensor-independent approach to the vicarious calibration of satellite ocean color radiometry

The retrieval of ocean color radiometry from space-based sensors requires on-orbit vicarious calibration to achieve the level of accuracy desired for quantitative oceanographic applications. The approach developed by the NASA Ocean Biology Processing Group (OBPG) adjusts the integrated instrument and atmospheric correction system to retrieve normalized water-leaving radiances that are in agreement with ground truth measurements. The method is independent of the satellite sensor or the source of the ground truth data, but it is specific to the atmospheric correction algorithm. The OBPG vicarious calibration approach is described in detail, and results are presented for the operational calibration of SeaWiFS using data from the Marine Optical Buoy (MOBY) and observations of clear-water sites in the South Pacific and southern Indian Ocean. It is shown that the vicarious calibration allows SeaWiFS to reproduce the MOBY radiances and achieve good agreement with radiometric and chlorophyll a measurements from independent in situ sources. We also find that the derived vicarious gains show no significant temporal or geometric dependencies, and that the mission-average calibration reaches stability after approximately 20-40 high-quality calibration samples. Finally, we demonstrate that the performance of the vicariously calibrated retrieval system is relatively insensitive to the assumptions inherent in our approach.     

白车身视觉检测系统中多类型传感器全局校准技术

针对白车身视觉检测系统中传感器数量多、种类各异、分布空间大、位置关系复杂等问题,提出了一种适用于工业现场的多视觉传感器全局校准技术。基于坐标系间接统一法,设计多个精密立体靶标作为坐标系转换中介,利用激光跟踪仪获取现场校准数据,在单位四元数数学模型的基础上,求解两坐标系间最优转换矩阵,将固定式传感器和柔性传感器的测量坐标系统一到全局坐标系。该方法已在某企业在线测量项目中成功应用,现场只需完成传感器坐标系与全局坐标系转换关系标定,降低了复杂现场环境对多传感器全局校准的限制,简化了校准过程,提高了环境适应性,校准后检测系统各向测量精度均优于±0.2 mm,满足白车身在线测量精度要求。     

Aperture Proximity Effects in High Heat Flux Sensors Calibration

In the transfer calibration of heat flux sensors, a correction for the irradiance distribution across the sensing area may be required when the sensing areas of the reference and test sensors are different. A method to calculate this correction using well-known equations for the configuration factors is presented. Also, estimates of the correction for test conditions corresponding to the transfer calibration technique in use at the National Institute of Standards and Technology are given.     

Modeling, calibration, and correction of nonlinear illumination-dependent fixed pattern noise in logarithmic CMOS image sensors

At present, most CMOS image sensors use an array of pixels with a linear response. However, pixels with a logarithmic response are also possible and are capable of imaging high dynamic range scenes without saturating. Unfortunately, logarithmic image sensors suffer from fixed pattern noise (FPN). Work reported in the literature generally assumes the FPN is independent of illumination. This paper develops a nonlinear model y=a+bln(c+x)+/spl epsi/ of a pixel for the digital response y to an illuminance x and shows that the FPN arises from a variation of the offset a, gain b, and bias c from pixel to pixel. Equations are derived to estimate these parameters by calibrating images of uniform stimuli, taken with varying illuminances. Experiments with a Fuga 15d image sensor, demonstrating parameter calibration and FPN correction, show that the nonlinear model outperforms previous models that assume either only offset or offset and gain variation.     

阵列光电传感器的非线性校正

阵列光电传感器在接近饱和时表现出非线性,但是可以通过阵列传感器的线性区的系数外推得到修正,而且只需在一个波长位置测得曝光量与A/D转换值的响应曲线,将能够推广到任意波长位置。为此,利用最小二乘法进行多项式拟合和软件的非线性校正,在同等硬件配置的条件下,增加了线阵传感器的线性区,延拓了传感器的动态范围。在整个动态范围内,系统测量误差可以减少到±2%。此非线性校正方法也非常适用于光电阵列传感器的光谱仪生产厂的强度定标校正。