电池内阻测试仪电阻参数的校准

针对电池内阻测试仪测量电阻参数的特殊性,文章通过介绍三种不同的测试方法,论述了如何模拟电池真实情况校准电池内阻测试仪电阻参数。经过对此三种测试方法测试原理的比较和多次测试数据的分析,发现改良后的测试方法符合电池内阻测试仪电阻参数的校准要求,数据稳定,操作简单。     

标准电阻应变模拟仪的检定

目前国内检定标准应变仪大多用电阻式交流分压器,相对准确度一般为(1～5)×10~(-3),可在音频范围内使用,属于此种类型的标准器件有BYM型应变模拟仪和应变校正器等,它们的共同特点是电阻网络。我们是采用感应分压器作为标准比率器件来进行检定。关于电感网络与电阻网络的等效问题,是采用“感应分压器——电阻匹配网络”解决的。由于应变模拟仪已普遍采用,且有可适用于直流和交流的优点,故本文围绕着它的检定作梗概的介绍。一、感应分压器——电阻匹配网络感应分压器的原理图如图1,它是一个具有多盘的多位读数的分压器,在音频时,其输     

电池内阻测试仪校准方法

本文主要从电池内阻测试仪的工作原理入手,总结出电池内阻测试仪的校准方法以及需要注意的问题。     

氧化锌避雷器测试仪阻容网络校准方法

对氧化锌避雷器测试仪的传统阻容网络校准方法进行分析,指出电阻的时间常数、电容的损耗因数对泄漏电流的校准有一定影响。提出了基于相位差测量的数字化校准方法,采用数字采样方法对关键参数相位差进行测量,通过实验验证,证实了该方法具有较高的准确度,可用于氧化锌避雷器测试仪的校准。     

1000V多盘感应分压器标准建立

中国计量科学研究院研制了一台1000V多盘感应分压器标准装置,用作工频1000V电压比例标准。该装置使用了一种基于互感器注入的误差补偿技术,可准确提供从1×10^-8到1的宽范围比例出。感应分压器的误差校验使用了包含三同轴屏蔽技术的改进型参考电势增量法,并设计了多比例参考互感器以便对感应分压器进行整体校验。所研制的感应分压器准确度优于1×10^-7,校准结果不确定度小于2×10^-8。     

高准确度有源双级感应分压器的研制

双级感应分压器工作于低频状态时,线圈自感阻抗降低使得分压器输入阻抗相应降低,导致分压器的误差变大。在不增大分压器铁芯的基础上,利用辅助绕组和有源电子电路补偿激磁绕组漏阻抗上的电压,使分压器的输入阻抗在工频时能提高数百倍,从而提高感应分压器的准确度。有源感应分压器结构简单,工作可靠,本文对其原理和制作方法进行了介绍。在不同频率下对感应分压器比例进行了自校准,结果表明感应分压器保持了高准确度。     

锂离子电池内阻测试方法研究

在深入研究锂离子电池内阻形成原理的基础上,通过对现有锂离子电池内阻测试方法的分析研究,证明了利用锁相放大器提高交流内阻测量精度的原理方法,并提出了基于不同荷电状态下的直流内阻谱概念和不同频率下的交流内阻谱概念.由于内阻谱包含了更多电池性能方面的信息,在实际测量中与传统测量方法相比有一定的优越性.     

引信电池性能存储测试方法研究

论述了引信电池性能对引信工作的影响,分析了引信电池测量技术现状,提出了一种采用存储测试技术测量引信电池性能的方法,利用该方法设计并研制了体积微小、安装简单、使用方便、能够承受高过载的弹丸弹上电池测试仪,该测试仪能测量实弹发射条件下的电池电压和电流特性,测量精度高.     

基于交流测量法的蓄电池内阻测量装置的研究

对传统的几种蓄电池单体电池内阻测量方法如密度法、开路电压法和直流放电法进行了比较分析 ,指出了它们的优缺点。提出了一种新的蓄电池单体电池内阻测量装置 ,该装置以MC6 8332单片机为控制核心 ,采用交流测量法 ,实现了蓄电池单体电池内阻的在线测量。着重介绍了该装置的工作原理以及硬件与软件设计     

绝缘油介电强度测试仪校准方法

通过分析绝缘油介电强度测试仪的工作原理,针对常规校准中存在的问题,设计一套中间接地的双电容分压器矢量信号测量装置,可对0~100 kV的准确度为2%以下的绝缘油介电强度测试仪进行校准。解决油杯阻抗匹配问题,满足对于测试仪矢量输出量值的准确溯源。     

电机定子匝间绝缘测量用冲击分压器性能试验研究

在研究电机定子电气性能检验装置校准方法项目过程中,研制了一种采用高压无感电阻、等电位屏蔽措施、二级分压结构和分布电容调节技术的冲击分压器,它被用于电机定子匝间绝缘项目的冲击电压峰值和波前时间的测量。经过试验,该电阻分压器的分压比误差小于0.5%;上升时间小于100ns,满足测量指标要求。     

高准确度直流电阻分压箱的校准

分析了直流电阻分压箱的技术指标和校准水平，提出了等分测量的校准方法，进行了不确定度分析，给出了验证方法。结果表明：用该方法校准的分压箱，比率误差为１０＾－７量级。     

A High Accuracy Self-Calibrating Bridge with Coupled Inductive Ratio Arms Used for Standard Inductors Comparison

A bridge with inductively coupled ratio arms based on a seven decade inductive voltage divider is described. It is used for mutual comparisons between the standard inductors which form the IEN reference bank of inductance. Provided some auxiliary balances are made, this bridge is able to measure its own residual inductances, both the inductances of the standard-to-bridge connections (about 2 ?H), made constant by the rigidity of the system geometry within a few nanohenries, and those of the variable resistance elements, also known within a few nanohenries. The self-calibrations are sufficiently accurate because the bridge has a high sensitivity even in comparisons of 1-?H inductors and in the use of ratios up to 1:100. Three variable resistance components are used to balance the bridge: a commercial box of 1-? steps, with calibrated inductance increments; a two-material helicoidal-motion wire resistor (0 to 1 ?), suitably designed with inductance variations less than ±1 nH; and a constant-geometry three-decade Kelvin-Varley divider, also designed for this specific purpose, with its total and partial inductance measured, and its total inductance kept constant within 1 nH. Where possible, connections between bridge components are realized by rigid tetra-axial conductors (4 coaxial tubular conductors). To avoid inductive coupling between the standards and the third tubular conductor, it is made of coated wires aligned along the generatrices of a cylinder. Provided the phase errors of the inductive voltage divider are known only within 1 ?rad, the bridge has an estimated ratio accuracy of ±[2.     

基于改进型两次平衡对检法的感应分压器自校准方法

介绍了参考电势变压器和指零仪变压器设计原理,分析了屏蔽间泄漏对测量结果的影响;对常规两次平衡参考电势对检法进行了改进,使零平衡和段平衡测量过程中,参考电势和测差电路均可实现等电位保护;对自校准方法进行了推导,校准结果仅与段平衡和零平衡时锁相放大器测量的电压差值相关,与参考电势变压器、指零仪变压器、辅助变压器等的误差无关,屏蔽间泄漏的影响也得到消除。对1kV感应分压器进行了校准实验,并对校准结果进行了测量不确定度分析,其相对扩展不确定度的评估结果为5.4×10^-8(k=2)。     

组合式高阻箱及高压表检定装置

介绍一种既是高压分压箱 ,又是高值电阻器的装置。它与通用型的 QJ36电桥、检流计、高压电源一起组成了一台高阻箱、高压表检定装置 ,适合于省、局级计量机构及大型企业计量机构使用。     

Characterisation of a Selection of AC and DC Resistance Bridges for Standard Platinum Resistance Thermometry

Accurate resistance bridges are used to measure the ratio between the resistance of standard platinum resistance thermometers and a reference (standard) resistor at the level of microkelvin in temperature terms and as such play a critical role in the realisation and dissemination of the ITS-90. For AC bridges, the ratio test unit has been available for some time, and for both AC and DC bridges, the increasing availability of resistance bridge calibrators based on combinatorial calibration has increased the ease with which the accuracy and linearity of resistance bridges may be determined, under conditions which provide a realistic representation of the actual measurement set-up. In this study, the performance of 14 resistance bridges, which were available for testing at NPL, consisting of a range of manufacturers and types, has been evaluated and expressed in terms of the standard deviation of the bridge errors over a given range of ratios, namely s. In general, the bridges are found to comply with the manufacturers’ specifications. The uncertainty of s has also been determined using Monte Carlo techniques and is found to be of the order of 10 % of s for most bridge types.     

基于标准表法的精密数字测温仪校准方法

参考流量与电学计量领域利用标准表对仪器进行校准的方法,提出一种采用高精度的测温电桥与高稳定性的直流电阻箱组合作为标准装置,校准精密数字测温仪的方法.用此方法对精密数字测温仪进行校准并进行测量不确定度分析,结果表明在-195 ～660℃氛围内,温度示值误差的合成标准不确定度为0.5 ～0.7 mK.此方法采用的标准器准确...     

A low-voltage and high-frequency ac-dc transfer system usinginductive dividers

A setup for the calibration of high-input-resistance ac-measuring instruments for low voltages (mV) and high frequencies (1 MHz) is presented. The low voltages generated down to one hundredth of an ac standard voltage (0.5 V to 2 V) are traced by means of a one-decade inductive voltage divider (IVD) cascaded by a sub-IVD with a fixed ratio of 10-to-1. Construction details of the main IVD which are necessary to meet the requirements are given. The error characteristics are mainly determined by capacitive currents acting on stray and mutual inductances. The internally built-in resistive dc voltage divider and a special switch allow calibrations to be performed via effective ac-dc transfer at the standard voltage level. The first results for the calibration of a transfer standard, Fluke 792A, at 100 mV and 200 mV were in good agreement with results obtained with very sensitive multijunction thermal converters. Using such converters as standards in the new system will enable ac calibrations down to voltages below 1 mV     

Maintaining the Unit of Voltage at PTB via the Josephson Effect

In Section I a report on high precision voltage comparisons between the mean EMF of the former PTB voltage standard (consisting of a group of 39 saturated Weston cells) and the Josephson reference voltage is presented. The experiments were carried out with a total uncertainty (1 ?) of 4 parts in 108. The measured rate of change of the mean EMF during a 1?year period was - 1.3 X 10-7 V per year. This voltage stability is sufficient to maintain the unit of voltage by this group of standard cells for several months until a new comparison with the Josephson reference voltage becomes necessary. Due to the effects of thermal EMF's in the millivolt circuit of the measuring system used at present, the Josephson reference voltage (?3 mV) is only stable during a short time. In Section II a prototype cryogenic voltage standard developed at PTB is described. By immersing the main measurement components into the superfluid liquid helium bath, a long term voltage stability can be achieved. These components include the cryogenic resistive divider, consisting of a new copper alloy, and the SQUID null detector. The resistance ratio of the cryogenic resistive divider of 320:1 is determined by a ten-decade inductive voltage comparator operating at 84 Hz. The effects of power dissipation introduce only errors of second order because the currents in the calibration mode and the measurement mode are the same.