Selecting parameters and limits for equipment operational qualification

While operational qualification (OQ) is a well-established term within equipment qualification, users of equipment often become unsure when it comes to implementation. The biggest problem is how to select procedures and acceptance criteria. Should these be the vendor's specifications or should the users define their own limits, and, if so, how? Should all instruments of the same type have the same values or should these be optimized for each individual instrument? This article will provide an overall strategy and specific examples for HPLC on how to select procedures and acceptance limits that are based on efficient use of resources, on practicality and on the intended use of the equipment.     

从初装费的变化看我国通信网发展的不同阶段

本文介绍我国电话初装费在电话网不同发展阶段的情况。文章认为,我国在解放后很长一段时间内,由于实行低初装费政策,导致企业投资过低,电信网发展缓慢。１９７９年提高初装费标准后,保证了电话网建设的１／３的资源来源。１９７９年提高初装费标准后,保证了电话网建设约／３的资金来源。从现在起,我国将逐渐下调初装费,这将进一步促进电信市场的发展,另一方面,电信网建设的融资方式也将进一步市场化。     

HL-2M 磁体系统安装中的定位与测量

为提高磁体系统安装精度,在 HL-2M 集成大厅建立 63 个基准点构成测量基准网,并利用激光跟 踪仪等高精度测量设备建立每个磁体的局部坐标系,测量特征点的局部坐标;基于测量基准网和公共测量点,采 用最佳拟合得到坐标转换矩阵,以此得到特征点在测量基准网的位置,指导磁体安装。完成安装后的中心柱同支 撑基础的同轴度为∅2.03mm;PF1~PF4 线圈安装标高偏差为±0.5mm,与中心柱的同轴度为∅2.60mm;PF5/6/7/8 线圈与中心柱的同轴度偏差小于∅3.00mm,标高偏差在[−1mm, 1mm]区间内。基于以上方法所得到的线圈安装精 度都满足设计需求。     

空调室外机送风系统研究

送风系统是空调室外机的重要组成部分,送风系统的好坏,很大程度上决定了整机的性能和噪音水平。对于室外机,风机是主要噪音源,也是室外机进行换热的驱动源。讨论在设计空调室外机时,对于整个送风系统应该重点关注的地方,如何设计才能保证其低的噪音水平和高的换热性能,并根据实际的工作经验和试验结果对比,给出了优化的方向和方法。另外为了使空调送风系统能更好的工作,对于产品的安装和使用也提出了要求。     

长春邮件处理中心工艺设备安装工程监理实践

通过对长春邮件处理中心工艺设备安装工程监理的实践，详细论述了监理过程中监理工程师应采取的措施，并提出了邮件处理中心工艺设备安装工程监理中应注意的几个问题。     

深圳某电厂H型钢桩沉桩与效果测试

在上部为花岗岩块石填土、下部为相对软弱的粘性土 ,地下水与海水相通的地区进行大型工程建设 ,主要建 (构 )筑物采用桩基础是安全可靠的措施 ,但采用何种桩型、沉桩时怎样才能顺利穿过花岗岩块石填土是一个值得研究的课题。采用潜孔锤引孔穿过花岗岩块石填土 ,往孔内回填碎石 ,然后打H型钢桩 ,在深圳某电厂地基处理中获得了较好的效果     

断路器弹簧机构现场安装调试常见故障的处理方法

弹簧操动机构是断路器的核心元件,对电力系统的安全性有直接影响.本文对断路器弹簧机构的安装调试过程中常见故障进行分析,并且对故障解决方法进行探讨,旨在提高电力系统运行的安全性.     

Acoustic characteristics of a heavy duty vehicle cooling module

Studies dedicated to the determination of acoustic characteristics of an automotive cooling package are presented. A shrouded subsonic axial fan is mounted in a wall separating an anechoic- and a reverberation room. This enables a unique separation of the up- and downstream sound fields. Microphone measurements were acquired of the radiated sound as a function of rotational speed, fan type and components included in the cooling module. The aim of the present work is to investigate the effect of a closely mounted radiator upstream of the impeller on the SPL spectral distribution. Upon examination of the SPL spectral shape, features linked specifically to the source and system are revealed. The properties of a reverberant sound field combined with the method of spectral decomposition permit an estimation of the source spectral distribution and the acoustic transfer response, respectively. Additionally, purely intrinsic acoustic properties of the radiator are scrutinized by standardized ISO methods. A new methodology comprising a dipole sound source is adopted to circumvent limitation of transmission loss measurement in the low frequency range. The sound attenuation caused by the radiator alone was found to be negligible.     

909工程超大规模集成电路厂房高纯气体管道的应用

简述909工程高纯气体管道系统设计中气体管道材料的选用,及设计对管道的施工安装,试压及验收的要求。     

关于PLC控制的机电一体化设备的安装及调试探析

不同于以前的手动操作时代,在当下自动化技术运用广泛的背景下,各种不同功能和用途的机电一体化设备正在行业发展的各大领域中得到推广和应用。因此,为了让众多机电一体化设备更好地运行,并有效提升机电设备的运行效率,需要专业人员在对机电一体化设备进行安装和调试时进行有效地分析,保障设备运行,降低故障率。本文会结合案实际例探讨如何对PLC控制的机电一体化设备的安装和调试进行分析。