碳纤维批次抽样检验方法的研究

碳纤维批次抽样检验数据能够客观地反映碳纤维批次整体的性能水平,同时也是出厂交付顾客的重要依据。但对于批次抽样数量如何规定,如何根据批次抽样检验数据判断批次接收与否,目前国内碳纤维企业往往难下定论。重点介绍了按计数抽样检验方案以及根据接收质量限(AQL)检索的批次检验判据。通过批不符合给供方施加压力,以推动供方提高自身质量水平,达到较好的接收质量限,从而降低顾客出现偶然收劣质批被接收的风险。     

产品抽样中应注意的问题

产品质量检验第一道工序就是从批量产品中按预定的方案抽取样本 ;经过样本的检验 ,分析计算出样本的质量指标 ,就样本的质量情况 ,推断批量产品总体的质量水平。因此 ,抽取样本的科学性在很大程度上决定了产品质量检验结果的代表性和真实性。如果抽样方法不合理 ,就可能接收质量低劣的产品 ,或者拒收质量优良的产品。前者对消费者是巨大的不幸 ,后者给生产经营者带来巨大的风险。为排除或减少产品质量检验中的风险 ,在抽样方法选择上必须注意以下问题。一、检验批的确定所谓检验批是指需要检验并由同型号的单位产品组成的集合。对这一概念的…     

产品抽样中应注意的问题

产品质量检验第一道工序就是从批量产品中按预定的方案抽取样本。经过对样本进行检验、分析,计算出样本的质量指标。通过样本的质量情况,推断批量产品总体的质量水平。因此,抽取样本的科学性,在很大程度上决定了产品质量检验结果的代表性和真实性。如果抽样方法不合理,就可能接收质量低劣的产品,或者拒收质量优良的产品。前者对消费者是巨大的不幸,后者给生产经营者带来巨大的风险。为排除或减少产品质量检验中的风险,在抽样方法选择上必须注意以下问题。 一、检验批的确定     

陶瓷产品外观质量监督检验固定样本数的抽检方案应当摈弃

众所周知,质量监督检验属于抽查型的,无疑是以抽样检验为主,即建立在由数理统计方法构造的抽样检验标准基础上,从要检验的一批(或某批)产品中随机抽取一部分产品(样本)进行检验,然后根据样本的质量数据对产品的批作出是否合格的判断.所谓批就是为实施抽样检查的需要而汇集起来的若干个单位产品称为检查批,简称批.产品批是抽检判定的基本单位,批中所含单位产品的数量称批量,一般以字母N表示.从批中抽取作检验用的单位产品称样本单位或佯品.一次抽检判定所用样本单位的     

浅谈普通定形耐火制品的验收抽样检验

根据产品的品种、订货量、生产条件、交付情况等对普通定形耐火制品进行组批,而后按可接收质量限AQL制定的检验方案抽取进行外观尺寸检验的样本,按产品质量标准的要求对其做出合格与否的判定。外观和尺寸合格的样本,应做批产品理化质量特性验收抽样检验,并按有关规定进行质量特性的合格与不合格判定。检验批所有应验收的理化质量特性全部合格,同时所包含的所有砖型子批的外观和尺寸质量全部合格,接收检验批,否则予以拒收。     

动态计量型抽样检验在企业质量管理中的应用研究

提出一种动态计量型抽样检验方法并应用于轨道机车产品检验。通过评估和筛选产品主要质量特性,结合企业当前产品质量水平和检测资源,针对产品主要质量特性制定一套基于抽样风险的动态计量型抽样检验方案,动态调整产品的使用方和生产方风险来改变抽样检验的严格性。应用实例表明,采用动态计量型抽样检验能有效指导质量检验人员对产品质量特性的监控,在关注产品质量特性是否合格的基础上深入了解产品质量特性的稳定性水平,从而推进产品生产过程质量改善。     

应用统计技术提高尿素质量审核管理水平

一、问题的提出 为了确定入库出厂前化肥包装质量的适用性和符合质量标准的程度,从用户使用的观点出发,需要在包装流水线上,从连续生产的在制品中抽样检验,或者是在站台或袋库中从码垛的包装件中抽样进行复检,以判断批包装质量能否满足用户的需要。包装件质量审核经历了从在线检验过渡到在线     

质量监督检验中化工产品抽样过程控制

化工产品的质量安全影响重大,需要建立完整的质量监督检验体系,加强抽样过程控制,确保产品质量检验结果的可靠性。本文首先对目前化工产品抽样过程中存在的问题进行分析,进而探讨合理的抽样检验方案制定策略,在此基础上,对化工产品质量监督检验的核心环节、产品抽样过程的控制方法进行研究,以期促进化工产品质检水平的提高。     

质量监督检验中化工产品抽样控制方法分析

化工产品的质量监督检验工作是检验化工产品质量的一种有效方法,本文针对化工产品的抽样控制方法,分析化工产品的现状及出现的问题,为提高抽样检验水平,提出一些相关的解决策略,确保化工产品的高质量生产,保证产品的质量安全.     

浅析质量监督检验的抽样方法、应用现状及存在的问题

目前,在还没有普遍适用的监督检验抽样标准或其它规定的情况下,各级质量监督管理和检验部门大多数根据自己的需要,制定自己管辖范围内监督检验的统一抽样方法,经有关部门审批后用以指导本地区的监督抽查工作,使这项工作做得更合理。因此质量监督检验适用的抽样方法是目前质量监督及检验人员必须解决的一项重要课题。统计抽样技术在我国的应用和发展总的来说起步较晚,进展缓慢,应用尚不普遍。在质量监督上的应用也不例外。由于监督检验只能采取抽查,因此从表面看应用统计抽样比较普通,但在应用的正确合理和效果方面尚存在不少问题。本文通过理论与多年实践的结果,探讨质量监督检验的抽样方法,应用现状及存在的问题,希望对质量监督检验工作有所裨益。     

澄清耐火材料质量检验中的几个错误观念

目前 ,在耐火材料企业中存在着一些错误的质量检验观念 ,如 :“检验结果发生异议时 ,加倍复验”、“按比例进行抽检 ,即百分比抽检”、“产品抽检合格 ,批中产品都合格”、“样本的合格品率等于提交批的合格品率”。本文就此予以澄清 ,同时对抽样检验理论进行阐述 ,建议在耐火材料质量检验中普及抽样检验 ,彻底根除目前耐火材料质量检验的错误观念     

Determination of optimal quick switching system with varying sample size for assuring mean life under Weibull distribution

Conventional sampling plans are applied to dispose an individual lot or isolated lot that requires a large sample size. Consequently, the inspection time and cost needed to make a decision under conventional plans are high. In order to reduce the sample size and to inspect the series of lots with minimum cost and time, special purpose plans are utilized. In this article, we propose one of the special purpose plans, namely, a quick switching sampling system that is also known as a two-plan sampling system. Through this sampling system, the Weibull-distributed mean life of the product is ensured based on time-truncated life tests. The proposed system is designed with the intention of minimizing the average sample number using two points on the operating characteristic curve approach. The optimal parameters of the proposed system are determined for different combinations of producer’s risk and consumer’s risk. Implementation of the proposed system is also explained and the performance of the proposed system is compared with other existing plans. In addition, the effects of misspecification of shape parameters on optimal parameters and the probability of acceptance are discussed.     

The relationship of peanut maturity to 2-methylpropanal in headspace volatiles

Headspace volatiles from peanuts of five consecutive maturity classes from three soil temperatures were determined to evaluate the relationship of peanut maturity and 2-methylpropanal. Cured, ground peanuts were held in closed vials for 30 min at 150 C before headspace sampling. Quantitation as percent of total volatiles and ppm in the peanuts revealed a decrease in 2-methylpropanal as peanuts matured regardless of seed size within maturity class. From peanut lots in which maturity-size relationships had been determined, headspace analysis of commercial sized lots indicated that the concentration of 2-methylpropanal was related to the maturity distribution (percent of each maturity class) within each sized lot. These data/techniques may have application in estimating lot-to-lot maturity-related peanut flavor/quality potential. Presented at the AOCS meeting in Honolulu, HI in May 1986.     

新型全柱状采样器研究与推广应用

由于煤炭是大宗产品,动力用煤煤量较大,供销频繁。电煤紧张时,煤炭供需双方质量纠纷不断,现行机械化采样器是按照标准煤炭产品设计的,在贵州省使用时存在很大的局限性,极不适应煤炭市场复杂的质量状况。企业使用中存在着很多问题,分层装车、不同品质的煤混装等造成购煤企业不能评价煤炭的真实质量,热值虚高,经济损失较大。根据现行机械化采样器存在的问题,提出了采用全柱状、全深度、全断面、全方位采取子样,子样量大且全部破碎缩分,解决了物料不均匀情况下的采制样难题,检验结果取得较好的准确性。     

特殊类型的DOE在质量验收方案研究中的应用

通过分割试验、计数型试验指标这一特殊DOE类型的应用,进行了批次产品质量验收流程改进的研究。结果表明:采用新验收方案保持了原方案中批次质量验收检验过程中不合格的检出力。新验收方案的应用,不仅在验收时间上缩短了20%,提高了质量验收过程的工作效率,而且节约了质量验收检验成本。     

Measurements of High Oleic Purity in Peanut Lots Using Rapid,Single Kernel Near-Infrared Reflectance Spectroscopy

High oleic peanuts have improved shelf life vs. conventional peanuts. Purity (percentage of high oleic peanuts within a lot) is critical to ingredient performance and final lot value. Contamination can result from unintentional mix-ups at the breeder/seed level, improper production handling, or due to physiologically immature high oleic kernels. Therefore, industry groups have established unofficial sampling plans to monitor purity. Assuming equivalent measurement performance and simple random sampling, increasing the sample size decreases variance among replicated sample test results and increases the precision of estimated lot purity. A novel instrument (QSorter Explorer by QualySense AG) using near-infrared reflectance spectroscopy was evaluated for high speed (20 kernels per second) high oleic purity measurements. The study objectives were to assess instrument performance in: (1) measuring oleic acid (%) in runner peanuts and (2) estimating the true high oleic purity of artificially mixed peanut lots. Three grades (Jumbo, Medium, and No 1) of US Runner mini-lots each at seven different contamination levels (0, 5, 10, 20, 30, 50, and 100%) were prepared. Oleic acid (%) of individual kernels was measured by scanning replicated samples of 10, 50, 100, and 500 kernels using the QSorter Explorer. The variance associated with each sample size and lot contamination level on returned purity values is discussed in the context of binomial sampling. Overall, the demonstrated measurement performance and capacity of the QSorter Explorer to process much larger sample sizes suggest this instrument can better identify true high oleic peanut lot purity vs. other currently available technologies.     

太阳能光伏组件用减反射膜玻璃产品质量国家监督抽查数据分析

近十年来,我国光伏产业迅猛发展,带动了光伏组件使用的关键原材料-光伏镀膜玻璃产业规模持续发展壮大。介绍了光伏镀膜玻璃的行业发展概况,通过整理分析近4次光伏镀膜玻璃产品的国家监督抽查数据,分析行业共性产品质量问题,并给出解决建议。     

Design and analysis of sampling plans to estimate aflatoxin concentrations in shelled peanuts

Methodology for use in the design and evaluation of sampling plans to estimate aflatoxin concentrations in lots of shelled peanuts is presented. Use of the operating characteristic curve for comparing and evaluating processor and consumer risks related to various sampling plans and application of the negative binomial distribution to estimate probabilities associated with sampling lots of shelled peanuts for aflatoxin concentration are discussed. Operating characteristic curves are developed for two different single-sample plans, an attribute multiple sample plan, and the plan presently used by the peanut industry to estimate aflatoxin concentrations in commercial lots of shelled peanuts. An estimated prior distribution of lots according to aflatoxin concentration is used to predict, among others, such values as the per cent of all lots tested that will be accepted by the sampling plans and the average aflatoxin concentration in the accepted lots. All four of the sampling plans described in the paper are compared on the basis of values such as these. Other factors to be considered in the critical evaluation and selection of sampling plans for estimating aflatoxin concentrations in commercial lots of shelled peanuts are discussed. Paper number 3197 of the Journal of Series of the North Carolina State University Agricultural Experiment Station, Raleigh, N.C.     

平板玻璃产品质量监督抽查的抽样、检验及判定——《产品质量监督抽查管理办法》解读

结合新的产品质量监督抽查管理办法,阐述了平板玻璃质量监督抽查的检验依据、抽样、检验要求。     

尿素净重抽样检测方法的探讨

列举了涉及尿素检测方法的各种采样标准,分析了这些方法存在的缺点。从生产实际和质量保证出发．提出了一个切实可行的检测方法,并进行了一些理论和实践的探讨,对化工产品净重抽样检测方法有一定的指导意义。