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About cotton wool regain experiment method report is measured implement a certain number of problems of the law

Published on:2013/6/13 19:04:06

Keyword:Cotton, determine appearance
Introduction:National level GB/T6102.2, 2009 " report of method of experiment of cotton wool regain is measured implement law " quality of nation of classics Peopl...

National level GB/T6102.2—2009 " report of method of experiment of cotton wool regain is measured implement law " quality of nation of classics People's Republic of China is supervised examine quarantine total bureau, GB turns administrative committee approval was released on April 23, 2009, carried out in the whole nation on September 1, 2009.

   The modification of this standard is a few problems that exist in the light of original standard, cultivate association of cotton of industry government department, China and Chinese cotton spinning to knit guild by Chinese fiber inspection bereau, Ministry of Agriculture (“ of the following abbreviation 4 branches ” ) the expert is concerned inside constituent industry, the castigatory on the foundation of the much test result that had by a definite date two years.

   Since the standard is released, below the joint efforts of concerned branch, the standard is carried out smoother and successful. Each district is used in new standard, especially new-style report is measured implement a few problems also feedbacked in using, the author studies as the project member and standard draft one of members, experienced the whole process that the project studies, also carried out a circumstance to begin survey inside the industry with respect to the standard, the relevant issue that wants to put forward with respect to concerned respect here is done elaborate further, in order to be helpful for new standard carry out smoothly.

   1 new standard and new-style report are measured implement the problem that should solve

   In “ organization of 4 branches ” finishs " temperature and humidity measures fixing noise and new-style report to pily regain implement " in experiment research project, the large-scale lab test that passes by a definite date two years and each amplification of representative area experiment of test and verify makes clear, XJ101 and Y412 report is measured implement the main problem that is put in 8 respects, measure with oven namely put in bigger error quite; Microtherm cannot be measured, compensation of the temperature below normal temperature is not accurate; Regain maths model is not accurate; Graduation is unscientific, nonlinear the problem is handled by linear; Test voltage grade is tall, phyletic much, to making, use and accurate measure brought inconvenience; Measure limits to cannot satisfy the requirement that low water tests; Lack grade, breed to wait to measure a way to report the processing of influencing factor; The technology is already backward, do not follow to go up need of pily estate development.

   In view of afore-mentioned circumstances, “ temperature and humidity measures calm influence ” to study the work to pily regain is to be based on oven law to be in - imitating test of limits of complete temperature and humidity is used below condition of ℃ of 30 ℃ ~50, obtained brand-new temperature and humidity to measure model of calm influence maths to pily regain, the pily regain that solved original standard and past basically checks the insufficient place that the instrument exists. Consider temperature compensatory effect for example, old instrument is measured hard to be less than the regain of 5% , a large number of experiments make clear, in this section, the regain data that its show often should be compared actual big 0.5% the left and right sides; The temperature that is like old instrument again amends coefficient, 7% above are unified by temperature every change 1 ℃ , regain corrects the incorrect practice of 0.1% . Theoretical analysis and many experiment all make clear, report measures the temperature of the law to amend coefficient to change along with regain size, in regain correction coefficient of the temperature inside the limits of 13% is 3% ~ 0.03% ~ 0.13% , to 7% the following regain determine, although old instrument already considered temperature to amend coefficient to differ along with regain size, but correction coefficient is measure a value with report and the 2 results value after pressing compensation is not a foundation to decide, below the condition that is far from 20 ℃ in temperature, the difference of both is bigger.

   By afore-mentioned seeing, the temperature that old instrument place uses amends coefficient to regain accurate measure will cause certain effect. Of new regain standard edit, also be to be in what make on the foundation that affirms research result adequately about the branch to edit, not be small on the foundation of old standard absolutely repair small those who fill.

   2 about same processing factory short-term inside the problem of difference of regain of a bale of cotton of treatment

   Same a processing factory, in same day or around the cotton of the same batch that machines inside a few days or different batch, the resurgence between the different bag of same batch is worth the occasional of each batch to also can have bigger difference. The account that produces this kind of phenomenon is many sided, main reason has:

   (1) at present our country cotton is the innumberable families is cultivated dispersedly, seed cotton origin basically is pily agent is in run, add the characteristic that seed cotton big stack piles up, the regain between different battlements can have the seed cotton before treatment probably big difference, it is same namely the cotton of big stack is in of the battlements each between also can put in bigger difference;

   (2) the diversity that change of air temperature and humidity accepts to bring about in machining a process

   The Qiu Dong that machines in cotton is seasonal everyday 10 when before reach 17 when later with 11 when ~ 17 when (the period of time of Xinjiang and inland have a difference) the atmospheric temperature and humidity during often can have very big difference, the change of its relative humidity can amount to 20% above. Change when the environmental relative humidity that deposits cotton 1% when, the regain of the cotton after the balance may change 0.08% ~ 0.15% , if relative humidity has the change of 20% , so regain diversity nature can be very remarkable.

   The cotton inside an a bale of cotton, its machine a process to arrive from stow seed cotton carry cotton gin to machine lint, carry packer to become a parcel again after that, whole process also counts ten minutes only. If be,fall in other normal ambient conditions, the cotton when environmental relative humidity is changed wants to be achieved below new requirement suck put wet balance, what need time to want to be in 24 hours commonly above. But in machining a process, cotton is in fleeciness condition, moreover cotton is to rely on what the wind-force with very big, very rapid rate carries pressure, in carrying a process, the transportation that becomes lint in rolling especially the cotton in the process is very fleeciness, at this moment cotton fiber is extremely easy from inside air current imbibe or release moisture content to the middle of air current, the regain that brings about oneself produces bigger change inside shorter time. It is to say cotton machined the special condition of the process to cause its namely the ultra encourage condition that regain changes, make the balance time that we cannot put wet process to know pily resurgence with groovy suction. For example, october, some processing factory in the morning 9 when machine cotton, the atmosphere relative humidity at that time is 70% , the true regain of seed cotton is big stack 11% the left and right sides, the regain that the cotton becoming a parcel that come out machines below this kind of condition should be in commonly 8% ~ 9% between; Arrived afternoon 1 when, the true regain of seed cotton still is in big stack 11% the left and right sides, but if atmosphere relative humidity fell 50% , the regain that machines the cotton becoming a parcel that come out at this moment can lie 6% ~ 7% between.

   3 detect about rising the problem that result accuracy should pay close attention to

   XJ130 new-style report is measured implement be according to new promulgated national level GB/T6102.2—2009 " report of method of experiment of cotton wool regain is measured implement law " the regulation makes. Model of correction maths of the mathematical model of the regain that this instrument place uses and resistance and temperature is to be in in below the fine bureau organization guidance jointly with branch of each experience cotton, all previous is built via experiment of full range temperature and humidity, its science sex and validity are nonexistent issue. So, if through legal fiber metric branch presses a country JJG845—2009 of metric calibrating regulations " cotton wool moisture determines appearance " the instrument of calibrating qualification, unless the instrument appears temporarily hardware breakdown, in use need not suspect the quality of instrument oneself the problem commonly, when affirming the test has deviation as a result, should collect from sample, the link such as processing and experiment method searchs an account. New-style report is measured implement when the test, collect besides the sample that should set according to the place on national level and instrument manual, outside processing and operation experiment method, still should note the following problem in practice:

   1) the uniformity with the hydrous sample that be measured. If each are nodded inside sample hydrous inhomogenous, certainly will causes bigger repetition to measure an error;

   2) when the sample that gives to cutting in pily treatment spot undertakes metrical, must rip pine hind to be measured again to sample, if check directly to original shape condition, measured value can reduce 0.5% or so;

   3) the sample that the lab brings back to measure after the spot is sealed, should have the balance with lab temperature, make the difference of cotton appearance temperature and lab temperature is not more than 2 ℃ . Below the situation that monitors directly to cotton appearance temperature in inconvenience, balance time should not be less than 4 hours, make sure difference is not more than the requirement of 2 ℃ very hard otherwise, bring about the generation that measures an error thereby.

   The draw-out sample when the spot flies the model that include a short slender pointed piece of metal releases rear body to accumulate at once to expand in bundle up pressure, suffer easily at that time the influence of environmental humidity, bring about regain to change and generation measures an error; Additional, if open packet of a short slender pointed piece of metal,measure with report instantly after appearance implement measure likely also because sample temperature and environmental temperature are abhorrent,the influence measures an outcome, because this should avoid as far as possible,in environmental temperature and humidity the condition of sharp change falls (as above midday 9 when before reach afternoon 5 when hind) appearance of a short slender pointed piece of metal opening a bag and test.

    4) the experiment makes clear, with polybag the means of sealed sample can not make sure pily moisture is absolutely and changeless, special it is when polybag is thinner the case is more severe;

   5) when sealed sample checks, if check the environmental humidity when environmental relative humidity and this sample are formed,differ too big, so, it is the change that also can make the moisture happening of sample surface bigger inside the shorter time that measures in the instrument namely, make thereby measured value deviate its female parent;

   6) grade is 5 class the following, or the meeting when pily impurity is too big makes report measures a value to slant big;

   7) be heated by oven the cotton after drying of 100 ℃ above, its physics function produces change likely, the report of the cotton that handles through this kind of means measures a value to be able to increase 0.3% the left and right sides;

   8) doing the ambient conditions when experimenting than noticing oven to answering when the experiment with oven law, if be below environment of standard temperature and humidity, the dry weight that says does not need to amend; If be in nonstandard the test has below environment of temperature and humidity, the means that the dry weight that says must provide by GB GB/T9995-1997 undertakes correction, otherwise, can cause 0.3% right-and-left measurement greatly most error.

   4 example error is analysed

   4.1 tests example

   Cotton of one odd futures examines at the beginning of November somewhere 2 batches, among them one batch is on November 2 afternoon 16: Appearance of 30 a short slender pointed piece of metal measures water, XJ130 temperature shows 15 ℃ at that time, 24 sample regain is average 6.4% , indication is in 6 ~ 6.9 between; The following day early 8: 10 check another batch of discovery when 24 sample indication is in 7.4 ~ 8.4 between, increase apparently, temperature shows 9 ℃ , these two batches of cotton machine date to be around day, the instrument sets the one night inside the car at that time, car and cotton are open air is deposited. After extracting above sample a short slender pointed piece of metal sealed put together with XJ130 indoor after two hours, temperature shows 15 ℃ , measure an indication to be in again 6.5 ~ 7.2.

   4.2 errors are analysed

   (1) although the pily treatment date of two batch is around day, unwarrantable also their resurgence value does not have bigger difference. Although a bale of cotton of same day treatment, in the morning, machine in the evening with medium, afternoon (inland 11 when ~ 17 when) also can appear of treatment 1% ~ 2% , taller even regain difference. The account that produces this kind of phenomenon is many sided, main reason has:

   The regain between different battlements can have the seed cotton before ① is machined probably big difference, it is same namely the cotton of big stack is in of the battlements each between also can put in bigger difference;

   ② machines the diversity that change of air temperature and humidity accepts to bring about in the process

   The Qiu Dong that machines in cotton is seasonal everyday 10 when before reach 17 when later with 11 when the airy temperature and humidity of 17 time often has ~ very big difference.

   (2) the statistic to regain of two batches of sample

   ① spot checks

   A) average of test of the first batch of 24 sample spots is 6.4;

   Average of test of the 2nd batch of 24 sample spots is B) 7.9;

   C)48 average of sample spot test is 7.15;

   ② lab checks

   48 sample are sealed the average that after temperature balances 2 hours, tests is 6.85.

   ③ difference is analysed

   Spot test and lab check, average difference is its regain 0.3% , possible reason is as follows:

   The sample when A) lab checks is sealed the time that undertakes temperature is balanced is not quite long (only 2 hours) , did not achieve the requirement of difference in temperature with experimental environment.

    The experiment proves, need ability of 4 hours above to make sealed specimen temperature satisfies the requirement that is not more than 2 ℃ with environmental temperature difference commonly. B) same sample checks in the spot (check) hind after warp density seals a balance, undertake 2 times again (lab) test, method of this kind of experiment brings about the generation of add error very easily. The reason is the resurgence after the sample in checking a process is arranged artificially may produce a few change.

   C) if the regain that sample nods each is not quite even, it is in the process of sealed balance this kind of inhomogenous sex also can produce change, produce an effect to checking a result then.

   The draw-out sample when D) spot flies the model that include a short slender pointed piece of metal releases rear body to accumulate at once to expand in bundle up pressure, suffer easily at that time the influence of environmental humidity, bring about regain to change and generation measures an error; Additional, if open packet of a short slender pointed piece of metal,measure with report instantly after appearance implement measure likely also because sample temperature and environmental temperature are abhorrent,the influence measures an outcome, the condition that because this should avoid as far as possible,changes quickly in environmental temperature and humidity lays appearance of packet of a short slender pointed piece of metal and test.