双活塞式压力计配套专用砝码的问题分析及解决方法

活塞式压力计是重要的标准压力计量器具.活塞专用砝码质量的准确与否,是衡量活塞式压力计的重要指标.本文对双活塞式压力计,两套活塞系统配备一套专用砝码使用产生的问题及原因进行了详细阐述,并给出相应问题解决方法.     

关于JJG59-2007《活塞式压力计》规程中活塞专用砝码质量计算公式的探讨

活塞式压力计是重要的标准压力计量器具.活塞专用砝码质量的准确与否,是衡量活塞式压力计的重要指标.JJG 59-2007《活塞式压力计》中活塞专用砝码的计算公式存在缺陷,导致压力的量值传递出现小必要的偏差.     

一种基于Lab VIEW的活塞式压力计检定数据处理系统

文章基于Lab VIEW设计了一套活塞式压力计计量检定的配套数据处理系统,方便活塞压力计专用砝码、活塞及其连接件质量进行检定。该系统结合JJG 59—2007 《活塞式压力计》国家检定规程中的检定要求,使用Lab VIEW开发平台建立可视化人机界面,设计并完成一套数据处理系统,可以准确有效的根据检定数据计算得到活塞式压力计专用砝码、活塞及其连接件质量,大大提高了工作效率。该研究为下一步在系统中增加活塞位置指示装置及原始记录自动生成和导出功能奠定了基础。     

气体活塞式压力计压力专用砝码质量的检定问题

气体活塞式压力计是高准确度压力标准器,是进行测量和校准表压和绝压的精密仪器,其工作原理是根据静力学平衡原理和帕斯卡定律,由加放在活塞上的已知作用力G(专用砝码产生的重力),与作用于已知活塞有效面积A上的被测压力p所产生的力相平衡。活塞及其连接件质量和压力专用砝码质量的准确与否,直接影响气体活塞式压力计压力值的准确度,本文对折算质量与真空中质量概念进行了介绍,并举例阐述了其对气体活塞式压力计的影响。     

关于二等标准活塞压力计活塞有效面积不确定度的分析

一、问题的提出在检定弹簧管式精密压力表时通常选用二等标准活塞压力计。根据其工作原理,二等标准活塞压力计产生的压力为P=W/S,W为砝码加活塞及上部圆盘的总重力,S为活塞的有效面积。因此,活塞式压力计的测量准确度主要取决于活塞的有效面积及专用砝码重量的测量准确度。由于专用砝码的测量准确度易于控制在0.005%之间,所以故活塞式压力计的测量准确度主要由活塞有效面积的测量准确度确定。国际法制计量组织建议,活塞初始有效面积的不确定度允许为综合准确度的50%。因此,分析活塞有效面积的不确定度,对提高活塞式压力计在测量中的准确度…     

质量砝码和压力砝码活塞式压力计的计量误差北大核心CSCD

活塞式压力计的砝码类型有压力标称砝码和质量标称砝码,二者产生误差的原理不同,导致误差结果也不相同。针对自由形变活塞,以形变系数对活塞有效面积的影响为基础,建立了压力误差模型,推导了使用压力标称砝码和质量标称砝码所产生压力相对误差的通项公式。以测量范围为10~510 MPa的活塞式压力计为研究对象,进行误差计算和对比分析,获得了2种砝码压力误差的变化规律。结果表明,同等条件下相较于质量标称砝码,压力标称砝码在各压力段内,由于重复使用无编号的小砝码会产生额外误差,最大可达-0.0041%。     

活塞式压力计专用砝码的溯源及质量修正

分析了活塞式压力计专用砝码质量修正对测量准确度的影响,并结合压力计量专业工作实际,阐述了活塞式压力计专用砝码溯源的重要性。通过空气浮力对专用砝码的影响分析以及活塞有效面积溯源结果给出了专用砝码质量修正的方法。     

新一代全自动活塞式压力计

正KY-Z2压力范围:0.1MPa~250MPa工作介质:液体KYQ-Z2压力范围:5kPa~100MPa工作介质:气体KY-Z2是新一代液体介质全自动活塞式压力计,量程上限可以达到250MPa,准确度等级覆盖0.005级至0.05级。KYQ-Z2是气体介质的全自动活塞式压力计,可以测量表压和绝压,当量程大于10MPa时,活塞工作形式为油润滑。该系列活塞压力计可实现全自动加码、全自动加压。量程和准确度等级与JJG59-2007《活塞式压力计检定规程》和JJG1086-2013《气体活塞式压力计检定规程》的要求一致。     

用数字压力计对二,三等标准活塞式压力计进行量值传递

二、三等标准活塞式压力计算量值传递以前都是采用间接法，即分别检定活塞有效面积和专用砝码质量，本文提出了用数字压力计直接对二、三等标准活塞式压力计进行检定，即采用直接比较法传递二、三等标准活塞式压力计的量值。     

简单活塞式压力计的误差修正

简单活塞式压力计是由专用砝码直接作用在活塞上的活塞式压力计，受到重力加速度影响、空气浮力影响、温度影响和活塞有效面积随压力改变的误差修正，以下就从这几点进行阐述：     

利用超高压力国家基准对返压活塞式压力计校准的试验研究

原超高压力国家基准准确度仅为0.1级，无法对0.05～0.1级的活塞压力计进行检定。现在新的1500MPa国家基准准确度达到了0.02级，为超高压活塞压力计的检定打好了基础。2005年利用新的国家基准对南京理工大学0．05级的1000MPa返压式活塞压力计和国营9319厂0.1级6000kgf／cm^2返压式活塞压力计作了校准。本文报告了校准时两台活塞压力计的压力平衡判断原则，介绍了一种较为成功的锰铜压力计间接比较法。     

一种活塞式压力计的数值研究方法

基于ANSYS流固耦合仿真技术,提出了一种活塞式压力计的数值研究方法,以0~250 MPa压力测量范围的简单型活塞式压力计为例,验证了该方法的可行性,并计算和分析了不同平衡工作压力下活塞间隙流体压力分布与活塞有效面积的变化规律。这种活塞式压力计数值研究方法,能有效搭建和模拟简单型活塞式压力计的三维模型,为活塞式压力计的理论研究提供新的思路。     

10 kPa气体活塞式压力计计量性能测试研究

用FPG8601型活塞式压力计作为标准器,对一台测量范围为1.2～10 kPa的气体活塞式压力计的活塞有效面积和鉴别阈进行了测试研究.介绍了标准器的特点和溯源方法,对被测器需要进行全量程测试的必要性和测试程序进行了阐述.测试覆盖了包括被测器测量下限在内的5个不同压力点,计算得到其活塞有效面积的平均值为9.773 71 ...     

Druckmessung im 10–3 mbar Bereich mit Wärmeleitungs‐ und Membran‐Vakuummeter

Pressure measurement in the mTorr range by thermal conductivity and diaphragm gauges For the reliable and simple pressure measurement in the mTorr range, the thermal conductivity and the capacitance diaphragm gauge can be used. Gauges of both types were employed for measuring the pressure in the bell jar of a piston gauge. The measuring characteristics of the gauges were checked regularly by calibrations and proved to be stable. According to the calibration data, the thermal conductivity gauge apparently is advantageous due to its better zero stability. In the practical use, however, substantial differences between the pressure readings of both gauges were observed. Therefore, in the present work the characteristics of both gauges have been investigated for the case of their actual usage, in which the pressure of an unknown gas has to be measured within a short time period. The investigations reveal, that the thermal conductivity gauge suffers from its slow response at small pressures and its dependency on gas species. In the present application, the capacitance diaphragm gauge proves as the far superior gauge.     

Kolbenmanometer mit Kraftmesszelle zur Kalibrierung sehr kleiner Drücke

Piston gauges are very precise pressure gauges. In the conventional design, the force exerted by the pressure balances the gravitational force on a piston or cylinder. Due to the mass of piston or cylinder, the smallest measurable pressure is limited to a few kPa (a few 10 mbar). The company DH Instruments, Inc. has developed a new piston gauge in which the pressure‐ induced force on the piston is measured by a mass comparator. Thereby, the measuring range is substantially extended towards smaller pressures. The instrument offers a measuring range from 1 Pa to 15 kPa (0,01 mbar to 150 mbar) for gauge and absolute pressure. The resolution is 1 mPa (10^‐5 mbar) and the uncertainty (5 mPa + 3·10^‐5 p). The piston gauge is calibrated through the determination of mass and piston‐cylinder effective area. An automated pressure controller is included in the instrument. Integrated software allows multi‐point calibrations with another device to be run unattended. The system has been used to perform an automatic test of capacitance diaphragm gauges in a variety of ranges.     

Differential resistance high-pressure gauges

Conclusions Above tests of the differential pressure gauge are not exhaustive, yet they confirm the exceptionally wide possibilities of its utilization for measuring small pressure differences at very high absolute pressures. In addition to the case under consideration [1] the differential pressure gauge can be used for investigating the fusing of substances under pressure by the method of clogging a capillary tube, for determining the pressure difference due to overcoming friction or to compressing a bellows in piston or bellows wave-pressure gauges, for detecting similar pressure differences in various types of separators and other similar cases.Precision measurements of pressures by means of the differential pressure gauge are of special interest in such cases when a direct connection of a piston pressure gauge is for some reason impossible. In such cases one of the differential pressure-gauge coils is connected to the equipment under test and the other to the piston pressure gauge, which is supplied with its own source of pressure. By means of the latter source the pressure in the piston gauge is raised until it becomes equal to that in the equipment under test. At the instant when the difference of the two pressures becomes equal to zero, according to the reading of the differential pressure gauge, the actual pressure in the equipment under test is determined directly by the reading of the piston gauge.In the above instances of the application of the differential pressure gauge, the theoretical side of the problem has been dealt with. In the practical application of the instrument; some modifications or additions to the design may be required according to the object of the tests, these alterations will not affect, however, the principle of its operation.     

指针式压力表自动计量校准系统

目前,指针式压力表常采用影像法进行计量校准,但在计量过程中存在压力表指针难分割、背景难分离和识别准确率低等问题,为解决上述问题,结合不同规格压力表表盘的外观尺寸,对压力表自动计量校准系统进行研究。首先,根据工业相机视野范围内压力表表盘外形尺寸,自动判断相机与压力表之间最佳工作距离;其次,利用图像边缘梯度值评价图像清晰度,自动完成相机对焦;最后,采用极坐标转换方法实现刻度线定位、指针提取、实时读数等功能。测试结果表明,该系统适用于外壳直径为40,60,100,150,200,250 mm的指针式压力表计量校准。     

活塞有效面积测量方法的分析和比较

测量活塞有效面积可以根据具体情况采用直接平衡法或起始平衡法。本文就基于压力形变系数及温度修正的起始平衡法与使用直接平衡法的测量数据进行比较分析,结果显示二者测量结果的一致性在不同的压力量程段有所不同。     

活塞压力计自动化校准方法研究

利用高精度压力传感器作为原位传递标准,提出了一种活塞压力计校准新方法。对传感器的分辨率和短期稳定性进行了测试,并评估了传感器线性系数对校准结果的影响。对比研究了新方法和传统方法的校准结果,两者的不确定度均约为5×10-6(k=1),且在不确定度范围内是一致的。在新方法的基础上研制了活塞压力计自动化校准装置,实现了压力控制、阀门操作和数据采集等功能的自动化。该自动化装置提高了活塞压力计校准的效率。     

Standardisierte Steckverbindung für aktive Vakuummeßköpfe

At the Gesellschaft für Schwerionenforschung, Darmstadt, an eight-pole interconnection for active vacuum gauges and corresponding controllers was standardized in collaboration with industry. It is suited for available gauges and gauges under development, which cover the whole technically interesting pressure range 10³–10¹² mbar. The interconnection contains the power lines for the gauge, the pressure signal as well as control lines for the various gauges. Just one type of connector is used thus facilitating stock keeping and use of different gauges. The chosen connector (known as modular connector) can be easily assembled without soldering. Furthermore, an encoder resistor installed in the gauge head allows an identification of the gauge by the controller. In this way, different gauges may be operated by the same controller or by the same PC plug-in module.