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本文详细介绍了一种对钟罩式气体流量标准装置的改造方案,改造后的钟罩式气体流量标准装置能够对具有脉冲输出并由试验确定仪表系数的流量计开展检测工作。 相似文献
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通过对钟罩式气体流量标准装置的不确定度分析,确定了该标准装置的合成标准不确定度和扩展不确定度,为气体流量计的检定提供了依据。 相似文献
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简要介绍某2000L钟罩式气体流量标准装置基本工作原理、特点、主要性能参数及存在的缺陷,针对不足之处提出改造方案。增加恒压供气系统,使装置同时具备进气、排气两种工作方式,提高装置工作压力,扩展计量能力。设计加工全新管路系统,满足正反进气、快速安装、快速准确流量调节等要求。设计自动控制测试系统,实现试验数据的自动采集及处理,装置自动控制,有效提高工作效率,减小人为误差。 相似文献
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钟罩式气体流量标准装置的现状及技术改造的必要性:随着国内外各种新型仪表的不断推出,技术含量高、自动化程度高的仪表越来越多。尤其是IC卡燃气表已成型及燃气用户的大量增加,对气体流量的计量提出了更高的要求。气体流量检测目前许多气体流量标准装置技术比较落后,还停留在人工读数的水平。工作量大、数据多,在检测中需要测得表前、表后和标准装置内部的温度、压力以及时间、体积值等一系列数据,再进行温度压力修正、计算出误差。人为因素对检测质量的影响很大。通过技术改造后,实现自动化控制来适应新技术发展,以满足社会上对… 相似文献
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采用测厚尺寸法评定钟罩式气体流量标准装置不确定度在现有研究中鲜有报道。依据测厚尺寸法的检定过程,对引起装置误差的各个方面分别分析计算,得到标准不确定度分量,合成后得到装置扩展不确定度Urel=0.40%,表明标准装置精度较高。 相似文献
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介绍了一种钟罩式气体流量标准装置自动检定系统.系统在现有钟罩装置的基础上,增加了由单片机与上位机组成的二级系统,实现了检定过程的自动控制与数据采集,并且将检定结果存入数据库,便于对检定数据进行管理.该自动检定系统的实现,对于提高气体流量仪表检定的效率和准确度具有实际意义. 相似文献
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随着科学技术的发展,以及国家新的计量标准相继出台,基于老版本标准开发的原有软件已反映出某些不适应。为适应我国加入WTO后流量测量与国际接轨的形势,确保标准软件与先进标准同步,保持其先进性,对mt法天然气流量标准装置进行技术改造、升级已迫在眉睫。本文介绍了眦法天然气流量标准装置的工作原理,并详细叙述了采用VB结合数据库开发计量软件的过程。 相似文献
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气体大流量标准装置的扩展不确定度评定 总被引:1,自引:0,他引:1
本文根据《测量不确定度评定与表示》(JJF1059-1999)中的规范化要求和有关数据,对国家原油大流量计量站成都天然气流量分站的气体大流量标准装置的测量不确定度进行了评定,结果表明该装置经过技术改造后的扩展不确定度不大于0.05%(P=0.95)。同1996年装置建立时的扩展不确定度0.1%(P=0.95)相比,又进一步提高了测量准确度。 相似文献
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pVTt法气体流量标准装置是国内外普遍使用的原级气体流量标准装置,主要用于音速喷嘴流量计的检测。附加体积处质量变化和泄漏量的准确评估是制约微小pVTt法气体流量标准装置测量准确度水平的关键因素。该文首先就附加体积处质量变化和泄漏量对微小pVTt法气体流量标准装置测量结果的影响进行理论分析,确定标准装置的不确定度;其次,以3支小音速喷嘴作为传递标准,对100 L pVTt法气体流量标准装置与2 m3 pVTt标准装置及德国物理技术研究院(PTB)的气体流量标准装置进行比对,比对结果的良好一致性可验证分析方法的可行性及装置的不确定度水平。 相似文献
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This paper presents the establishment and verification of a primary low-pressure gas flow standard with the capacity of 0.005
L/min to 24 L/min (at 23 °C and 101.325 kPa), newly established at National Institute of Metrology of Thailand (NIMT). This
facility is a mercury-sealed piston prover consisting of three precision-machined glass cylinders. Flow measurement can be
carried out manually or semi-automatically. The electronics were installed in a separate console to minimize their thermal
impact on the gas temperature. Special care was taken in designing the facility to ensure sound and representative gas pressure
and temperature measurement. The relative expanded uncertainty of mass flow measurement was evaluated to be less than 0.13%.
To verify the measurement capability and performance of the new facility, a bilateral comparison with the piston prover at
Center for Measurement Standards (CMS), Taiwan was conducted. The transfer standard used was a set of three critical flow
venturis with dedicated thermometers. Eight flow rates of dry air ranging from 42 mL/min to 14.5 L/ min at 0 °C and 101.325
kPa (0.055 g/min to 18.87 g/min) were tested. Comparison results showed that the E
n
values for the flow measurements at NIMT with reference to CMS were all well less than unity, demonstrating good agreement
between the two participants. 相似文献
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Microwave heating was employed for preparation of the standard gas of volatile organic compounds (VOCs) and semivolatile organic compounds (semi-VOCs) by using a 1000 W commercial domestic microwave oven and 1 L gas-sampling bulbs. The VOCs investigated were benzene, chloroform, 1,3-dichlorobenzene, tetrachloroethylene, toluene, and 1,1,2-trichloroethane, and the semi-VOCs used were the polychlorinated biphenyls (PCBs) PCB 1016 and PCB 1248. Since these weakly or nonpolar molecules are very poor absorbers of microwave energy, an appropriate amount of water was introduced to accept microwave radiation and act as the thermal source to accelerate their evaporation. The glass bulb may also contribute thermal energy to the VOCs/semi-VOCs by accepting microwave energy to a small degree. For 0.5 microL of liquid VOCs on 10 mg of glass wool, it was shown that 15 microL of H2O and 60 s of microwave heating yielded a very efficient evaporation [97.2-106.4%, compared with a classic method (Muller, L; Gorecki, T.; Pawliszyn, J. Fresenius' J. Anal. Chem. 1999, 364, 610-616)]. For 1 microL of PCB solution (1000 microg/mL in hexane), 15 microL of H2O and 90 s of microwave heating also provided a complete evaporation. The addition of water was particularly significant for microwave-assisted evaporation of PCBs because semi-VOCs are much more difficult to evaporate than VOCs. This developed microwave technique proved to be quite simple, powerful, rapid, accurate, and safe for the preparation of VOC/semi-VOC standard gas. Solid- phase microextraction combined with gas chromatography was used for the gas analysis. 相似文献