BS ISO 7700-2-2011 Food products Checking the performance of moisture meters in use Moisture meters for oilseeds《食物制品 使用的湿度计性能检测 油籽用湿度计》.pdf

1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS ISO 7700-2:2011Food products Checkingthe performance of moisturemeters in use Part 2: Moisture meters for oilseedsBS ISO 7700-2:2011 BRITISH STANDARDNational forewordThis Brit

2、ish Standard is the UK implementation of ISO 7700-2:2011. Itsupersedes BS 4289-8:1988 which is withdrawn.The UK participation in its preparation was entrusted to TechnicalCommittee AW/307, Oilseeds, animal and vegetable fats and oils andtheir by-products.A list of organizations represented on this c

3、ommittee can beobtained on request to its secretary.This publication does not purport to include all the necessaryprovisions of a contract. Users are responsible for its correctapplication. BSI 2011ISBN 978 0 580 70948 7ICS 67.200.20Compliance with a British Standard cannot confer immunity fromlegal

4、 obligations.This British Standard was published under the authority of theStandards Policy and Strategy Committee on 30 November 2011.Amendments issued since publicationDate Text affectedBS ISO 7700-2:2011Food products Checking the performance of moisture meters in use Part 2:Moisture meters for oi

5、lseedsProduits alimentaires Vrification des humidimtres en service Partie 2: Humidimtres pour graines olagineuses ISO 2011Reference numberISO 7700-2:2011(E)Second edition2011-11-01ISO7700-2INTERNATIONAL STANDARDBS ISO 7700-2:2011ISO 7700-2:2011(E)COPYRIGHT PROTECTED DOCUMENT ISO 2011All rights reser

6、ved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or ISOs member body in the country of the request

7、er.ISO copyright officeCase postale 56 CH-1211 Geneva 20Tel. + 41 22 749 01 11Fax + 41 22 749 09 47E-mail copyrightiso.orgWeb www.iso.orgPublished in Switzerlandii ISO 2011 All rights reservedBS ISO 7700-2:2011ForewordISO (the International Organization for Standardization) is a worldwide federation

8、 of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee.

9、International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.International Standards are drafted in accordance with

10、 the rules given in the ISO/IEC Directives, Part 2.The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval

11、 by at least 75 % of the member bodies casting a vote.Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights.ISO 7700-2 was prepared by Technical Committee I

12、SO/TC 34, Food products, Subcommittee SC 2, Oleaginous seeds and fruits and oilseed meals.This second edition cancels and replaces the first edition (ISO 7700-2:1987), which has been technically revised.ISO 7700 consists of the following parts, under the general title Food products Checking the perf

13、ormance of moisture meters in use: Part 1: Moisture meters for cereals Part 2: Moisture meters for oilseedsISO 7700-2:2011(E) ISO 2011 All rights reserved iiiBS ISO 7700-2:2011IntroductionThe calibration of moisture meters can, for stable samples and under ideal measuring conditions, prove entirely

14、satisfactory. On the other hand, the results obtained with the same moisture meter can be affected by many variables including: oilseeds species and variety, cultivation, ripeness, humidity, temperature, harvesting, transport and level of impurities, particularly for oilseeds received with high mois

15、ture content.ISO 7700-2:2011(E)iv ISO 2011 All rights reservedBS ISO 7700-2:2011INTERNATIONAL STANDARD ISO 7700-2:2011(E)Food products Checking the performance of moisture meters in use Part 2:Moisture meters for oilseeds1 ScopeThis part of ISO 7700 specifies a method of checking the performance of

16、moisture meters in service for measuring the moisture content of oilseeds.This part of ISO 7700 is not applicable to either cases of pattern approval or for initial calibration of moisture meters. The results of the verification described in this part of ISO 7700 are used to evaluate whether to chec

17、k fully or to repair the moisture meter.NOTE For built and pattern approval specifications, see OIML R 591.2 Normative referencesThe following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, th

18、e latest edition of the referenced document (including any amendments) applies.ISO 665, Oilseeds Determination of moisture and volatile matter content3 Terms and definitionsFor the purposes of this document, the following terms and definitions apply.3.1moisture contentmoisture mass fractionproducts

19、proportion mass loss, determined under specified experimental conditionsNOTE 1 For the purposes of this part of ISO 7700, the experimental conditions are specified in ISO 665.NOTE 2 It is expressed as a percentage mass fraction the format “% (m/m)” is deprecated.4 PrincipleComparison of the results

20、supplied by the moisture meter with those obtained by a reference method for the analysis of a same sample of grains.Use of at least two different species with, for each one, at least two samples having moisture contents as different as possible, and included within the moisture meters measurement r

21、ange.If local regulations specify that additional samples are required, proceed in order with them. ISO 2011 All rights reserved 1BS ISO 7700-2:20115 Apparatus5.1 Bottles, in glass, with airtight seals, of capacity approximately 2 l, 1 l, 0,5 l and 0,1 l, previously cleaned, rinsed and dried.5.2 App

22、aratus required for the determination of water content, by the reference method in accordance with ISO 665.5.3 Sieves, in particular with round holes of diameter 3,15 mm, or mechanical separator, fitted out with nettings, as specified by the purchaser.5.4 Thermometer.5.5 Sample divider.6 Preparation

23、 of samples6.1 Selection and cleaning of samplesSelect varieties of oilseeds from those which are the most prevalent in the region where the moisture meter is used.Clean the samples by manual sieving or with the help of the mechanical separator (5.3) using appropriate sieves (5.3) and remove the ele

24、ments having a bigger size than whole grains of oilseeds.6.2 Preparation of test samples6.2.1 Preparation of sample (A)Select at least two oilseeds species and, from each, select at least two samples having moisture contents as different as possible depending on the availability of samples, providin

25、g these are within the measurement range of the moisture meter controlled.Each sample (A) shall be composed of only one species.The samples (A) shall have their natural moisture, i.e. they shall not be conditioned by wetting or drying. Checking with grains which have a high moisture content is conse

26、quently only possible during the harvesting period.Samples shall be clean and homogeneous. If necessary, they may be cleaned following the requirements given in 6.1. Make each sample (A) homogeneous by shaking and inverting the bottle.The volume of each sample (A) shall be such that it fills by two

27、thirds a bottle of appropriate capacity (5.1).NOTE 1 If the bottle is too full, the sample cannot be completely mixed and if the bottle is not filled enough, there are hygrometric exchanges between the grains and the air present in the bottle, and a modification of the moisture content of the sample

28、 can occur.NOTE 2 If the moisture meter is used for measuring the moisture content of only one species, only this species is used to check the performances of the moisture meter.6.2.2 Preparation of sample (B)From each sample (A), divide quickly by using the sample divider (5.5) to obtain a represen

29、tative test portion (B), taking care to avoid any modification of moisture content of grain. Place the test portion (B) into another bottle (5.1), the capacity of which ensures that it is filled by two thirds, and close it.ISO 7700-2:2011(E)2 ISO 2011 All rights reservedBS ISO 7700-2:20117 Procedure

30、7.1 Initial reference moisture content determinationDetermine the moisture content of the test portion (B) following the reference method described in ISO 665.7.2 Stabilization of sample temperatureIt should be noted that a difference of temperature between the moisture meter and the test samples (A

31、 minus B) may have an influence on the measurement result. In that case (e.g. as stated by the pattern approval), samples and meter should be left to come to equilibrium before performing the test.Measure and record the room temperature with a thermometer (5.4). It is recommended that tests be carri

32、ed out under ambient temperature conditions in the range of 15 C and 25 C. If such conditions are not possible, the tests shall be carried out under the ambient temperature assigned for the working conditions of the moisture meter (see technical specifications of the manufacturer).No test conditions

33、 are defined regarding the relative humidity, except when they are specified by the manufacturer of the moisture meter.7.3 Checking of moisture meterMake the test sample (A minus B) homogeneous by shaking and inverting the bottle.On opening the bottle, examine the sample and make sure there is no tr

34、ace or odour of mustiness, fermentation or germination.With the moisture meter, make, at least, three successive measurements for each test sample (A minus B). After each measurement, put again the test sample (A minus B) into the corresponding bottle and re-mix before making the next measurement.NO

35、TE 1 The number of measurements can vary depending upon local regulation.One test sample (A minus B) can be used only:15 times, if the reference moisture content is less than: 12 % (mass fraction)9 times, if the reference moisture content is between: 12 % and 20 % (mass fraction)6 times, if the refe

36、rence moisture content is more than: 20 % (mass fraction)NOTE 2 Taking into account the moisture content of the samples, their shelf-life is limited.NOTE 3 Taking into account this previous indication, a same test sample (A minus B) can be used for checking several moisture meters.NOTE 4 If the tech

37、nology of the moisture meter is such that the oilseeds are milled in the meter, it is expected that the above-mentioned procedure be adapted, especially for the volume of the sample (A minus B), to perform the three measurements.7.4 Final reference moisture content determinationAfter checking the mo

38、isture meters (7.3), from each test sample, take quickly a second representative test portion (C) using the sample divider (5.5) and taking care to avoid any modification of its moisture content. Place the test portion (C) into another bottle (5.1), the capacity of which ensures that it is filled by

39、 two thirds and close it. Determine again the moisture content of this second test portion (C) following the routine reference method described in ISO 665.ISO 7700-2:2011(E) ISO 2011 All rights reserved 3BS ISO 7700-2:20118 Expression of resultsFor each test sample (A), the following data are obtain

40、ed:a) two results from the reference method,wH O,B2(initial determination: 7.1) andwH O,C2(final determination: 7.4);The difference between the values obtained shall not be more than 0,3 % w wH O,B H O,C%2 20 3 ( ), .If the difference is greater, repeat the test.The mean of these two values w wH O,B

41、 H O,C2 22+( )constitute the true value wH O2( )of the moisture content of the sample.b) three or more measurements wiH O,m2( )from the moisture meter (7.3);For each test sample, calculate the difference between each measurement wiH O,m2( )conducted with the moisture meter, and the reference result

42、measured by the reference method of the sample, wH O2( ), i.e. w wH O,m1 H O2 2( ), w wH O,m2 H O2 2( )and w wH O,m3 H O22( ).9 Maximum permissible errors As a matter of principle, the w wH O,m1 H O2 2( ), w wH O,m2 H O2 2( )and w wH O,m3 H O2 2( )values shall be lower than the following maximum per

43、missible errors (MPE), but local regulation may impose other MPE.9.1 Oilseeds other than sunflower seeds0,7 % (mass fraction in absolute value) for a moisture content, wH O2( ), equal to or less than 10 % (mass fraction).3 % (relative value) plus 0,4 % (mass fraction in absolute value) for a moistur

44、e content, wH O2( ), more than 10 % (mass fraction).9.2 Sunflower seeds0,8 % (mass fraction in absolute value) for a moisture content, wH O2( ), equal to or less than 10 % (mass fraction).4 % (relative value) plus 0,4 % (mass fraction in absolute value) for a moisture content, wH O2( ), more than 10

45、 % (mass fraction).NOTE Where the numerical value “X” is associated with the symbol “% (mass fraction in absolute value)”, it means the unit of measurement. Where the numerical value “X” is associated with the symbol “% (mass fraction in relative value)”, it means the percentage of the true value of

46、 the moisture content of the sample. See Examples 1 and 2.EXAMPLE 1 If the reference moisture value of a rapeseeds sample as measured using the reference method described in ISO 665 is 15 % (mass fraction), the maximum permissible error is: 0,4 + (0,03 15) = 0,4 + 0,45 = 0,85 % (mass fraction)EXAMPL

47、E 2 For a sunflower seeds sample having a reference moisture content lower than 10 % (mass fraction), the maximum permissible error is 0,8 % (mass fraction).ISO 7700-2:2011(E)4 ISO 2011 All rights reservedBS ISO 7700-2:201110 Test reportThe test report shall contain at least the following informatio

48、n:a) all the information necessary for the complete identification of the moisture meter checked (trade name, type, No. of series, etc.);b) the date and place of the checking;c) the name of the person who checked the moisture meter;d) the temperature of the test;e) the results obtained, together wit

49、h the values obtained for each measurement;f) all the information necessary for the complete identification of the samples used;g) the test method used with reference to this part of ISO 7700;h) all operating details not specified in this part of ISO 7700 or regarded as optional, together with details or any incidents which can have influenced the test results.ISO 7700-2:2011(E) ISO 2011 All rights reserved 5BS ISO 7700-2:2011Annex A (informative) Schematic representation of the procedure for each sample