ASTM E1697-2005 Standard Test Method for Unipolar Magnitude Estimation of Sensory Attributes《感官特征单极性光度评估的标准试验方法》.pdf
《ASTM E1697-2005 Standard Test Method for Unipolar Magnitude Estimation of Sensory Attributes《感官特征单极性光度评估的标准试验方法》.pdf》由会员分享,可在线阅读,更多相关《ASTM E1697-2005 Standard Test Method for Unipolar Magnitude Estimation of Sensory Attributes《感官特征单极性光度评估的标准试验方法》.pdf(10页珍藏版)》请在麦多课文档分享上搜索。
1、Designation: E 1697 05Standard Test Method forUnipolar Magnitude Estimation of Sensory Attributes1This standard is issued under the fixed designation E 1697; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision
2、. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method describes a procedure for the applica-tion of unipolar magnitude estimation to the evaluation of themagnitude of
3、sensory attributes. The test method coversprocedures for the training of panelists to produce magnitudeestimations and statistical evaluation of the estimations.1.2 Magnitude estimation is a psychophysical scaling tech-nique in which panelists assign numeric values to the magni-tude of an attribute.
4、 The only constraint placed upon thepanelist is that the values assigned should conform to a ratioprinciple. For example, if the attribute seems twice as strong insample B when compared to sample A, sample B shouldreceive a value which is twice the value assigned to sample A.1.3 The intensity of att
5、ributes such as pleasantness, sweet-ness, saltiness or softness can be evaluated using magnitudeestimation.1.4 Magnitude estimation may provide advantages overother scaling methods, particularly when the number of pan-elists and the time available for training are limited. Withapproximately1hoftrain
6、ing, a panel of 15 to 20 naiveindividuals can produce data of adequate precision and repro-ducibility. Any additional training that may be required toensure that the panelists can properly identify the attributebeing evaluated is beyond the scope of this test method.2. Referenced Documents2.1 ASTM S
7、tandards:2E 253 Terminology Relating to Sensory Evaluation of Ma-terials and ProductsE 1871 Practice for Serving Protocol for Sensory Evalua-tion of Foods and Beverages2.2 ASTM Publications:3Manual 26 Sensory Testing Methods, 2nd EditionSTP 758 Guidelines for the Selection and Training ofSensory Pan
8、el Members2.3 ISO Standards:4ISO 11056:1999 Sensory AnalysisMethodologyMagnitude Estimation MethodISO 4121:1987 Sensory AnalysisMethodologyEvaluation of Food Products by Methods Using ScalesISO/DIS 5492:1990 Sensory AnalysisVocabulary (1)ISO 6658:1985 Sensory AnalysisMethodologyGeneralGuidanceISO/DI
9、S 8586-1:1989 Sensory AnalysisMethodologyGeneral Guide for Selection, Training and MonitoringSubjectsPart 1: Qualifying Subjects (1)ISO 8589:1988 Sensory AnalysisGeneral Guidance forthe Design of Test Rooms3. Terminology3.1 Definitions:3.1.1 external modulusnumber assigned by the panelleader to desc
10、ribe the intensity of the external reference sampleor the first sample of the sample set. The external modulus issometimes referred to as a “fixed modulus” or just the“modulus.” In this case the reference is said to be modulated.3.1.2 external reference sample for magnitude estimationsample designat
11、ed as the one to which all others are to becompared, or to which the first sample of a set is to becompared, when each subsequent sample in the set is comparedto the preceding sample. This sample is normally the firstsample to be presented.3.1.3 internal modulusnumber assigned by the panelist todesc
12、ribe the intensity of the external reference sample or thefirst sample of the sample set. The internal modulus issometimes referred to as a “non-fixed modulus.” When aninternal modulus is used, the reference is sometimes said to beunmodulated.3.1.4 internal reference sample for magnitude estimations
13、ample present in the experimental set, which is presented tothe panelist as if it were a test sample. The value assigned tothis sample(s) can be used for normalizing panelists data. If anexternal reference is used, the internal reference(s) are nor-mally identical to it.1This test method is under th
14、e jurisdiction ofASTM Committee E18 on SensoryEvaluation of Materials and Products and is the direct responsibility of Subcom-mittee E18.03 on Sensory Theory and Statistics.Current edition approved April 1, 2005. Published April 2005. Originallyapproved in 1995. Last previous edition approved in 199
15、9 as E 1697 95 (1999).2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from ASTM Headquarters, 100
16、Barr Harbor Drive, PO Box C700,West Conshohocken, PA 1942829593.4Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.3.1.5 magnitud
17、e estimationprocess of assigning values tothe intensities of an attribute of products in such a way that theratios of the values assigned and the panelists perceptions ofthe attribute are the same.3.1.6 normalizingprocess of multiplying each panelistsraw data by, or adding to the logarithm of each p
18、anelists rawdata, a value which brings all the data onto a common scale.Also referred to as rescaling.3.1.7 Stevens Equation or the Psychophysical PowerFunctionR 5 KSn(1)where:R = the panelists response (the perceived intensity),K = a constant that reconciles the units of measurementused for R and S
19、,S = the stimulus (chemical concentration or physicalforce), andn = the exponent of the power function and the slope ofthe regression curve for R and S when they areexpressed in logarithmic units.In practice, Stevens equation is generally transformed tologarithms, either common or natural:lnR 5 lnK
20、1 nlnS (2)3.2 Reference Terminology E 253 for general definitionsrelated to sensory evaluation.4. Summary of Test Method4.1 Panelists judge the intensity of an attribute of a set ofsamples, presented in random order, on a ratio scale. Forexample, if one sample is given a value of 50 and a secondsamp
21、le is twice as strong, it will be given a value of 100. If itis half as strong it will be given a value of 25. There are threeprocedures that can be used.4.1.1 Panelists are instructed to assign any value to describethe intensity of the first sample (external reference, which mayor may not be part o
22、f the sample set). Panelists then rate theintensity of the following samples in relation to the value of theexternal reference.4.1.2 The external reference is pre-assigned a value (modu-lus) to describe its intensity by the panel leader. Panelists ratethe intensity of the following samples in relati
23、on to the externalreference and the modulus.4.1.3 Panelists rate the intensity of each subsequent samplein relation to the preceding sample. The first sample of the setmay or may not have a modulus.4.2 Individual judgments can be converted to a commonscale by normalizing the data. Three normalizing
24、methods canbe used: internal standard normalizing, external calibrationand, if a modulus is not used, no standard normalizing (methodof averages). See 11.4 and Appendix X2-Appendix X4.4.3 Results are averaged using geometric means. Analysisof variance or other statistical analyses may be performed a
- 1.请仔细阅读文档,确保文档完整性,对于不预览、不比对内容而直接下载带来的问题本站不予受理。
- 2.下载的文档,不会出现我们的网址水印。
- 3、该文档所得收入(下载+内容+预览)归上传者、原创作者;如果您是本文档原作者,请点此认领!既往收益都归您。
下载文档到电脑,查找使用更方便
5000 积分 0人已下载
下载 | 加入VIP,交流精品资源 |
- 配套讲稿:
如PPT文件的首页显示word图标,表示该PPT已包含配套word讲稿。双击word图标可打开word文档。
- 特殊限制:
部分文档作品中含有的国旗、国徽等图片,仅作为作品整体效果示例展示,禁止商用。设计者仅对作品中独创性部分享有著作权。
- 关 键 词:
- ASTME16972005STANDARDTESTMETHODFORUNIPOLARMAGNITUDEESTIMATIONOFSENSORYATTRIBUTES 感官 特征 极性 光度 评估 标准 试验

链接地址:http://www.mydoc123.com/p-529263.html