4 Development testing
4.1 Classification of tests
Tests as the main form of control products represent the experimental determination of the qualitative and quantitative properties of the product as a result of exposure to operations, as well as in the simulation object.
The purpose of the various tests at different stages of designing and manufacturing products.
When it comes to defining “test”, must proceed not from the English term “test” (which, as you know many values), and from the traditional norms of the Russian language. According to these norms, the test always assumes any impact or load. The test is pass or don't pass.
Testing is a form of control. In the test system includes following main elements:
a) test object - a product test.
b) test conditions - a set of influencing factors and / or modes of operation of the facility during the test. The test conditions can be real or simulated;
b) means testing is the technical devices required for testing. This includes measuring tools, test equipment and auxiliary technical devices;
g) the executors of the test is the personnel involved in the testing process. To him are requirements for qualification, education, experience and other criteria;
d) normative-technical documentation on the tests, which are a set of standards governing the organizational-methodological and normative-technical basis of tests; a set of standards for the system development and launch of new products; technological normative and technical documents regulating the requirements and test methods;
Normative and technical documents regulating the requirements to the means testing and the use of them.
The test conditions and the list of monitored parameters of electronic products are stipulated in the standards and General technical conditions (TU) on the product.
All the tests are classified according to the methods of conducting, purpose, stages of design, manufacturing and production, referring to the finished product, duration, level of organization, type of impact, determined by the characteristics of the object.
The result of exposure to electronic products tests are divided into destructive and non-destructive, but also on durability, strength and resistance.
The tests are destructive, if their conduct is used destructive methods of control or as a result of influence of external factors the test samples unsuitable for further use. NDT methods are used instead as destructive, and in addition to them. This reduces the time of analysis of failures, and in some cases more accurately establishes the location and type of defect.
Most test methods of electronic products are either destroying or significantly reducing the lifespan of products. Also due to the decrease in production volume of the products there are situations when the amount of samples for destructive testing becomes comparable to the volume of production. Therefore, the most widely used in practice trials received a sampling method that allows you to judge the entire population of products taken from the sample.
If the products that are included in the sample, fully reflect the nature and structure of the General population, this sample is called a representative or representative.
The sample is classified on several grounds:
a) according to the method of education (repeated and unrepeated);
b) justification of selection (intentional and accidental);
b) in relation to the time of education (one-time and casual);
g) for the intended purpose (stratified and obdarovavani).
Table 7-Types, purposes, tasks and objects of tests
Types |
Test objectives |
Problems of tests |
Objects |
1 |
2 |
3 |
4 |
The research |
Choice and justification of characteristics of the projected production |
1.The study of analogues. 2. Verification of own production. 3.Preparation specification. |
Analogs, model samples, batch production |
The honing |
Working off of a design in the course of design |
1. Definition of characteristics of the projected production. 2.Assessment compliances to the projected production to the specification. 3. Search of ways of improvement of indicators of quality. |
Prototypes, analogs |
The preliminary |
Determination of readiness of a product for acceptance tests |
1.Assessment of compliance of production technical job. 2.Definition the actual charakteristic production. 3. Preliminary definition of need for spare parts. 4.Definition possibilities of representation of production on acceptance tests. |
Prototypes |
The acceptance |
Making decision on statement on production |
1. Determination of compliance of production to requirements of standards and to the specification. 2. Obtaining information on readiness of a product for certification. 3. Making decision on statement of a product on production. |
Prototypes |
The adjusting |
Check of readiness of production for production |
I.Check qualities of the products made on the accepted technologies. 2. Check readiness productions to release the developed production. |
Samples of the first the industrial parties |
The certified |
Obtaining certificate and mark of conformity |
1. At formation compliances of characteristics production to requirements safety and ecology. 2. Inclusion in the state register and receiving licenses for the right productions. |
The identified samples |
Periodic, control |
Control stability Productions |
1. Check compliances production to specifications and to standards. 2. Assessment stability productions and qualities of the serial production. 3.Identification short comin gsthe serial prodl. 4.Assessment efficiency actions, introduced in the serial production. |
Samples of a batch production |
The inspection |
Check of compliance of a batch production to the certified sample |
1. Definition compliances the serial production to requirements safety and ecology. |
Samples of a batch production |
The acceptance |
Acceptance production customer |
1.Definition characteristics of production. 2.Assessment compliances qualities charasteric production to contract vaniye. 3.Identification of short comings and their elimination. |
Samples of the handed-over party |
Operational supervision) |
Assessment compliance of products to service conditions |
1. Definition values of indicators qualities in the conditions of the real operation. 2.Identification of shortcomings production. 3. Studying of demand of the consumer. 4. Collecting information on features operation of the various conditions. |
Serial samples, being in operation |
The duration of all tests are divided into:
a) normal test - the test methods and conditions which ensure obtaining the necessary scope of information on the reliability of the product at the same time as during operation;
b) accelerated testing - test methods and conditions which provide the necessary information about the quality of the product in a shorter period of time;
in) short-circuit test - a test carried out under the reduced program.
The purpose of the tests can be divided into study and control.
Research tests are conducted to study certain characteristics of the properties of the product. The results of these tests are used for the following tasks:
a) determine or assess indicators of quality of functioning of the test products under certain conditions;
b) selection of optimum performance and reliability;
c) comparing the plurality of implementation variants of the product in the design and certification;
g) constructing a mathematical model of the functioning of the product (estimates of parameters of the mathematical model);
e) selection of significant factors influencing the indicators of quality of functioning.
Research testing if necessary at any stage of the product life cycle.
Tests carried out for quality control of the object, called watches. The purpose of the control test verification of compliance during manufacture. Control tests make up the largest group of tests.
The goals and objectives of the tests change over the life cycle of a product. In this regard, it is clear the selection test in stages. In these phases is carried out finishing, preliminary and acceptance tests.
Finishing testing research, and conduct them in the design of products with the aim of assessing the impact made to the technical documentation of changes to achieve specified values of quality indicators. The need for testing is determined by the developer or in the preparation of technical specifications for the development or in the development process; it is the program and methods of testing.
The tests subjected the prototypes of products.
Preliminary tests control for prototypes and (or) experimental batches of products. They are carried out to determine the possibility of filing a test sample for acceptance testing.. the pre-test as close as possible to the operating conditions of the product. The organization of the tests is the same as in finishing the test. According to test results execute the act, the report and determine the possible submission of a product acceptance test.
Acceptance tests are also control for prototypes, pilot batches or single pieces. Acceptance testing of the prototype carried out in order to determine compliance of products with technical specifications, standards and technical documentation, evaluation technical level, the definitions for the formulation of new products.
Testing of finished products are divided into qualification, acceptance, periodical, standard, inspection, certification.
Qualification tests conducted in the following cases: when assessing the readiness of the enterprise for the production of specific products, if manufacturers of prototypes and serial products are different, as well as in the formulation for production licenses and products developed by another entity. In other cases, the need for qualification tests acceptance Committee sets.
The tests subjected the samples from the first production batches), as well as the first samples of products manufactured under license and developed by another company.
The composition of these tests include all tests specified in the normative-technical documentation, except to check the persistence.
Routine testing is carried out for decision making about the suitability of the products for delivery or use. The tests subjected every manufactured unit or a sample from the batch.
Periodic tests are conducted to:
a) periodic quality control of products;
b) control the stability of the technological process in the period between ordinary tests;
b) approve the continuation of manufacturing of products at the then-current documentation;
g) confirm the level of quality of the product released during the controlled period;
e) confirm the effectiveness of the test methods used during acceptance inspection.
Periodic tests are designed to produce steady-state serial (mass) production.
Type tests - control of products of the same size using the same methodology, which is carried out to evaluate the effectiveness and feasibility of changes to the design or manufacturing process. These tests are random, as are the damaging tests, designed to assess the resistance of structures under different types of mechanical and environmental influences.
The inspection tests are a special kind of check tests. Implement them selectively to control the stability of quality of samples of finished products and products in service.
Certification testing - an element of the system of measures aimed at confirming the compliance of the actual characteristics of the product to the requirements of normative-technical documentation. Certification test, generally conducted by independent test centers. According to the results of the tests will receive a certificate or mark of conformity of product to requirements of normative-technical documentation. Certification involves mutual recognition of test results the supplier and the consumer.
In addition to the tests carried out by the manufacturer, the product can be checked when the input control of the consumer. When the input control should not be thermal shock, thermal cycles, prolonged vibration, mechanical shock, multiple test products test voltage. Invalid test products in modes other than those listed in the technical specifications. Used for incoming inspection, measuring, test equipment and benches shall conform to the requirements for similar equipment and benches supplier.
Depending on the nature of the impact on products of all WWF are divided into classes: mechanical, climatic and other natural, biological, radiation, electromagnetic fields .
It should be noted that the improved control of the design process and the technological process of manufacturing products leads to a decline in the role of finished product testing. Well-organized automated control of technological process of production reduces the amount of testing of finished products. Given the need to optimize the cost of the product, it is necessary to find a reasonable compromise between volume testing and performance monitoring of manufacturing products.
4.2 Equipment and instruments for testing. Means of measurement.
4.2.1 Equipment and devices for determining the chromaticity
Laboratory scales 3rd grade precision with the greatest limit of weighing 1 kg according to GOST 24104.
A photometric device that allows you to select wavelength (420±5) nm permissible absolute error in the measurement of transmittance of not more than 0.5%.
Photometric cuvette length less than 3 cm, each pair of the ditch should be marked accordingly.
The membrane filter or a glass pore size 0.45 µm.
The liquid-in-glass thermometer with scale division of 1 °C and a measuring range from 0 to 100 °C according to GOST 28498.
Water bath.
Thermostat.
Refractometer for the determination of dry matter.
Funnel In-100-150 XC GOST 25336.
The flask KN-2-250-34/40/ TCS GOST 25336.
Distilled water according to GOST 6709.
The filter paper according to GOST 12026.
Cylinder 1 /3/ - 100 GOST 1770.
pH meter.
Diatomaceous earth beyond 10.04-852* or perlite.
The one mentioned here and hereafter, are the author's development. For additional information, please refer to the link. - Note the manufacturer's database.
Sodium hydroxide according to GOST 4328, solution molar concentration mol/DM is prepared as follows:
4.0 g of sodium hydroxide was dissolved in distilled water in a volumetric flask with a capacity of 1000 cm and the volume was adjusted to the mark with water.
Allowed the preparation of the reagent from the corresponding fixanal.
Hydrochloric acid according to GOST 3118, solution molar concentration mol/dm is prepared as follows:
8,2 cm of concentrated hydrochloric acid density ( g/cm ) was diluted with distilled water in a volumetric flask with a capacity of 1000 cm to the mark.
Allowed the preparation of the reagent from the corresponding fixanal.
Allowed to use other equipment, reagents and materials specifications not below the established standard.
4.2.2 Equipment and devices for determination of sucrose
The held compensation with quartz wedge or with a rotating compensator with international sugar scale, equipped with a monochromatic light source, with a limit of measurement uminus 40 to 120 °Z (sugar" degree) or automatic polarimeter with the permissible basic error of ±0,05 °z
Cylinder 1-10-2, 1/3/-100-2, 1/3/-1000-2 GOST 1770.
The volumetric flask 2-100-1 GOST 1770, calibrated with a tolerance on the capacity of ±0.1 cm . If necessary, calibration flasks is carried out in the laboratory.
Watch mechanical GOST 10733 or stopwatch.
Laboratory scales General purpose of the 2nd accuracy class with the greatest limit of weighing 200 g and 3rd class with precision
the greatest limit of weighing 1 kg according to GOST 24104.
The General purpose hydrometer with a range of measurement of the density of 1000-2000 kg/m GOST 18481.
The liquid-in-glass thermometer with a temperature measurement range from 0 to 100 °C and a scale division of 0.1 °C according to GOST 28498.
Thermostat liquid temperature range 20-150 °C, creating a temperature deviation from set value ±0.1 °C.
The cuvette polarimetric length (200,00±0,02) mm, (100,00±0,02) mm coverslip of clear optical glass of a thickness of 1-2 mm with parallel and smooth surfaces.
The control cuvette with quartz polarimetric plates.
Cup Nickel-silver.
Funnel In-100-150 vehicle according to GOST 25336.
Glass W/d/-1/2/TC -250 GOST 25336.
The porcelain mortar with pestle, GOST 9147.
Glass hour.
Water bath.
Bottle.
The glass wand.
Wand wood.
Pipette with a fine tip or a syringe for injection.
Paper laboratory grade filter f - GOST 12026.
Charcoal active charcoal powder according to GOST 4453 or imported.
The ethyl ether.
The lead acetate according to GOST 1027.
The lead oxide on the legal document.
Aluminum sulfate (basic) with a mass fraction of aluminum oxide
with (a ) not less than 18% of the normative document.
The indicators are: litmus, phenolphthalein.
Distilled water according to GOST 6709.
Allowed to use other equipment, labware, and reagents with the metrological and technical characteristics are not included below.
4.2.3 Equipment and instruments for the determination of ash
Laboratory scales General purpose of the 4th class of accuracy with the greatest limit of weighing 500 g - GOST 24104.
Conductivity meter, calibrated in units of electrical conductivity measurement range from 0 to 150 s/Cm or percent ash.
Thermostat liquid, creating a temperature deviation from set value ±0.1 °C.
The liquid-in-glass thermometer with a measuring range from 0 to 100 °C and a scale division of 0.1 °C according to GOST 28498.
The volumetric flask 1(2)-100-2 - in accordance with GOST 1770.
Funnel In-100-150 XC - GOST 25336.
Paper laboratory filter brands FOB, FB, FS, FM, GOST 12026.
Distilled water according to GOST 6709.
Potassium chloride according to GOST 4234.
Allowed to use other equipment, laboratory glassware with metrological and technical characteristics are not below the established standard.
4.2.4 Equipment and instruments for the determination of reducing substances
Measurement tools, accessories, materials, reagents
Cylinder 1-5-2, 1-500-2, 1-1000-2 GOST 1770.
The volumetric flask 1(2)-100-2, 1(2)-200-2, 1(2)-1000-2 GOST 1770.
The flask KN-2-250-34 TCS GOST 25336.
Pipettes with a capacity of 20 cm and 50 cm according to GOST 29169 or a graduated pipette with a capacity of 25 cm according to GOST 29228.
Burette with a capacity of 50 cm with the smallest scale division of 0.1 cm according to GOST 29252.
The glass In(N)-1(2)-150 GOST 25336.
Funnel In-100-150 GOST 25336.
Laboratory scales General purpose of the 2nd class of accuracy the greatest limit of weighing 20 g, 2nd accuracy class the greatest limit of weighing 200 g and 4 th grade precision with the greatest limit of weighing 500 g GOST 24104.
The liquid-in-glass thermometer with a scale interval of 0.1 °C and a measuring range of temperature from 10 °C to 100 °C according to GOST 28498.
Laboratory pH meter with boundaries of measure from minus 1 to 14 pH and ranges from minus 1 to 14 pH, from pH 5 to 8; from 4 to 9 pH.
Stopwatch or watch mechanical GOST 10733.
The porcelain mortar with pestle, GOST 9147.
Glass hour.
Thermostat liquid, creating a temperature deviation from set value ±0.1 °C.
Water bath.
Paper laboratory grade filter f according to GOST 12026.
Distilled water according to GOST 6709.
Lead acetate according to GOST 1027.
Sodium carbonate GOST 83.
Phenolphthalein (indicator) according to the normative document.
Acetic acid according to GOST 61.
Copper sulfate 5-water GOST 4165.
Potassium sodium tartrate 4-water GOST 5845.
Sodium carbonate 10-water GOST 84.
Coal active brightening wood powder according to GOST 4453.
Sodium hydroxide GOST 4328.
Iodine GOST 4159.
Potassium iodide GOST 4232.
Starch soluble GOST 10163.
Sodium thiosulfate according to GOST 27068.
Potassium dichromate according to GOST 4220.
The isobutyl alcohol according to GOST 6016.
Allowed to use other equipment, labware, and reagents with the metrological and technical characteristics are not included below.
For the preparation of reagents allowed the use of standard titles.
Preparation of solutions reagents must be complied with GOST 27025.
4.2.5 Equipment and instruments for the determination of reducing substances
Measurement tools, accessories, materials, reagents
Cylinder 1(3)-25-2, 1(3)-100-2, 1(3)-500-2, 1(3)-1000-2 GOST 1770.
The volumetric flask 1(2)-100-2, 1(2)-200-2, 1(2)-1000-2 GOST 1770.
The flask KN-2-250-34 TCS GOST 25336.
Pipette with a capacity of 20 cm and 50 cm according to GOST 29169 or a graduated pipette with a capacity of 25 cm according to GOST 29228.
Burette with a capacity of 50 cm with the smallest scale division of 0.1 cm according to GOST 29252.
The glass In(N)-1(2)-1000 TCS GOST 25336.
Laboratory scales General purpose of the 2nd class of accuracy the greatest limit of weighing 20 g, 2nd accuracy class the greatest limit of weighing 200 g and 4 th grade precision with the greatest limit of weighing 500 g GOST 24104.
The liquid-in-glass thermometer a scale interval of 0.1 °C and a measuring range of temperature from 10 °C to 100 °C according to GOST 28498.
Laboratory pH meter with a measurement range from minus 1 to 14 pH and ranges from minus 1 to 14 pH, from pH 5 to 8; from 4 to 9 pH.
Stopwatch or watch mechanical GOST 10733.
The porcelain mortar with pestle, GOST 9147.
The burner gas.
Glass hour.
Thermostat liquid, creating a temperature deviation from set value ±0.1 °C.
Mesh with asbestos plate with a hole diameter of 35 mm.
Water bath.
The glass wand.
Paper laboratory grade filter f according to GOST 12026.
Distilled water according to GOST 6709.
Ceramic is porous.
Lead acetate according to GOST 1027.
Sodium phosphate disubstituted 12-water GOST 4172.
Sodium phosphate disubstituted GOST 11773.
Coal active brightening wood powder according to GOST 4453.
Copper sulfate 5-water GOST 4165.
Sodium carbonate GOST 83.
Sodium carbonate 10-water GOST 84.
Potassium sodium tartrate 4-water GOST 5845.
Acetic acid according to GOST 61.
Hydrochloric acid according to GOST 3118.
Potassium iodide according to GOST 4232.
Iodine GOST 4159.
Sodium hydroxide according to GOST 4328.
Potassium dichromate according to GOST 4220.
Sodium thiosulfate according to GOST 27068.
Starch soluble GOST 10163.
The isobutyl alcohol according to GOST 6016.
Allowed to use other equipment, labware, and reagents with the metrological and technical characteristics are not included below.
For the preparation of reagents allowed the use of standard titles.
Preparation of solutions reagents must be complied with GOST 27025.
4.3 Preparation of samples for testing
4.3.1 Preparation for the test to determine the chromaticity
Before measuring, check the zero value of the instrument.
4.3.2 Preparation for the test for determination of sucrose
300 g of lead acetate triturated in a porcelain mortar with 100 g of lead oxide and 100 cm of distilled water. Porcelain mortar with the mixture was placed in a boiling water bath and heated with stirring until then, until the original yellow mass takes on a white or pink color. Then, while mixing, add parts 900 cm hot distilled water and transfer the mixture into a bottle. The operation is repeated several times, depending on the capacity of the bottle. Filled the bottle and leave in a warm place for 3-5 days, occasionally stirring the solution with a wooden stick.
After clarification, the solution was filtered. The filtered solution was stored in tightly closed bottles.
Lead the vinegar should have a strong alkaline reaction to litmus and slightly alkaline to phenolphthalein.
The density of the solution should be p 20 = 1235-1240 kg/m , the lead content in terms shall be (100±2) kg/m .
The prepared solution of lead vinegar should not come into contact with the carbon dioxide .
Preparation of the solution of the basic aluminum sulfate
To 122 g of basic aluminium sulphate is added 1000 cm of distilled water, left overnight and then thoroughly mixed.
Before the test you must check the scale held by using a quartz plate with a known value of polarization for light source. The measurement is performed at a temperature of (20,0±0,5) °C. If the measurement at this temperature it is impossible to produce, the value of polarization of the light of the quartz plate is calculated by the formula
Z t = Z 20* [ 1+0.00014*(t-20)], (1)
where 0,00014 is constant;
- the value of polarization of the light of the quartz plate at a temperature of 20 °C;
the measurement temperature, °C.
When using the held compensation with quartz wedge its temperature and plates, as well as reading held at the specified tube is not determined.
4.3.3Preperation to test for ashes definition
Before carrying out test check correctness of indications of the conductometer by means of solutions of chloride potassium of a certain molar concentration which electric conductivity is known. Check is made on the methods attached to the conductometer.
4.3.4Preparation to test for definition of reducing substances
Preparation
of solution
of
acetic lead
Dissolve 300 g of 3-water acetic lead (
)
in 800 sm
distilled
waters
in a measured flask with a capacity of 1000 cm
,
if necessary establish rn by the 7th solution of acetic acid or a
hydroxide of sodium and bring volume the distilled
water
to a tag.
Preparation
of solution of carbonic sodium (
)
mass fraction of 14%
dissolve 140 g of carbonic sodium the
distilled water in a measured flask with a capacity of 1000 cm
and
bring volume the distilled
water
to a tag.
Preparation of solution of acetic acid of molar
concentration
mol/dm
Dilute
300 cm
of
ice acetic acid with the distilled water in a measured flask with a
capacity of 1000 cm
and
bring volume the distilled water to a tag.
Preparation of a reactant of Müller
Müller's reactant is prepared mixing of solutions A and B.
Solution
A: 35,00 g of 5-water sulfate copper (
)
dissolve in 400 smkipyashchy
the
distilled water.
Solution B: 173,00 g of 4-water tartrate
potassium-sodium and 68 g of waterless carbonic sodium dissolve in
500 cm
of
the boiling distilled water or 183,50 g of 10-water carbonic sodium
dissolve in 400 cm
of
the boiling
distilled
water.
After dissolution and cooling solution B is flowed to
solution A in a measured flask with a capacity of 1000 cm
and
bring volume the distilled
water
to a tag.
Add 3 g of active coal to a measured flask, shake up and leave for 2 h. Then solution is filtered through filter paper. In case of loss of a deposit of an oxide of copper at long storage solution is filtered again.
Solution is stored in ware from dark glass with a prishlifovanny stopper at the room temperature.
Preparation
of solution of a hydroxide of sodium of molar
concentration
mol/dm
Dissolve
40 g of a hydroxide of sodium the distilled water in a measured flask
with a capacity of 1000 cm
and
bring volume the distilled
water
to a tag.
Preparation
of solution of iodine of molar concentration
mol/dm
Dissolve
4,30 g of resublimated iodine in the water solution containing 10 g
of iodide potassium, carefully mix before full dissolution of iodine
and bring the volume of solution the distilled water to 1000 cm
.
The correction coefficient of solution of iodine is established at least 1 time in 10 days on sodium thiosulphate solution according to requirementsof GOST 25794.2. Solution is stored in ware from dark glass with a price stopper at the room temperature.
Starch solution preparation by a mass fraction of 1% Pound 1 g of starch in a porcelain mortar from 25 cm of the distilled water. The received starched milk is poured in 74 cm of the boiling water.
Sodium
thiosulphate solution preparation (sernovatistokisly sodium) of molar
concentration
mol/dm
Dissolve
8,40 g of thiosulphate of sodium in 100 cm
of
the svezheprokipyachenny distilled water, cool, add 3 cm
of
isobutyl alcohol, carefully mix and bring volume to 1000 cm
.
The correction coefficient of solution is established in 10 days on
solution of bichromate of potassium of molar
concentration
mol/dm
COUNTRY
CHURCHYARD
25794.2.
Solution is stored in ware from dark glass at the room temperature.
Potassium bichromate solution preparation (dvukhromovokisly potassium) of molar concentration mol/dm
Dissolve 1,6345 g of the potassium bichromate which is dried up at 150 °C in the distilled water and bring solution volume water to 1000 cm .
Preparation of initial solution of raw sugar Weigh 40 g of raw sugar with a margin error of ±0,01 g, dissolve in the distilled water, transfer to a measured flask with a capacity of 200 cm , clarify neutral solution of acetic lead in quantity from 1,0 to 4,0 cm , checking completeness of sedimentation by addition of one drop of neutral solution of acetic lead. Bring volume the distilled water to a tag, shake up and filter via the paper filter, covering a filtering funnel with hour glass in order to avoid evaporation and change of concentration of solution. Select a pipette 50 cm of a filtrate, transfer to a measured flask with a capacity of 100 cm , add solution of carbonic sodium ( ) with a mass fraction of 14% in the presence of the indicator of a fenolftalein (before weak pink coloring) for removal of excess of acetic lead, bring volume to a tag the distilled water, shake up and filter via the paper filter.
Preparation of initial solutions of granulated sugar, refined sugar Weigh 40 g of granulated sugar or refined sugar with a margin error of ±0,01 g, dissolve in the distilled water, transfer to a measured flask with a capacity of 200 cm and bring volume the distilled water to a tag.
4.3.5 Conduct to test for definition of definition of the reducing substances
Preparation
of neutral solution of acetic lead (
)
mass fraction of 10%
Dissolve 100,00 g of 3-water acetic lead ( ) in 800 smdistillirovanny waters in a measured flask with a capacity of 1000 cm , if necessary establish rn by 7 solutions of acetic acid or hydroxides of sodium and bring volume the distilled water to a tag.
Preparation
of solution of disubstituted phosphorly sodium (
)
mass fraction of 10%
Dissolve
100,00 g of disubstituted 12-water phosphorly sodium (
)
in the distilled water in a measured flask with a capacity of 1000
cm
also
bring volume the distilled
water
to a tag.
Preparation of solution of Offner
Dissolve
in a glass the distilled water 5,00 g of 5-water sulfate copper,
10,00 g of carbonic sodium or 27,00 g of 10-water carbonic sodium,
300,00 g of tonkoizmelchenny 4-water tartrate potassium-sodium, 50,00
g of disubstituted 12-water fosfornokisly sodium or 19,80 g of
disubstituted fosfornokisly sodium, bring the distilled water to 700
cm
.
The glass with solution is heated on a water bath, periodically
stirring slowly with a glass stick. After full dissolution of
components heating is continued on the boiling water bath of 2 more
h. Then solution is cooled to 20 °C, transferred to a measured flask
with a capacity of 1000 cm
and volume bring the distilled water to a tag. Add 2 g of active
coal, vigorously shake up and filter through filter paper. Solution
is stored in ware from dark glass with are polished stopper at the
room temperature.
Preparation of solution of hydrochloric
acid of molar concentration
mol/dm
Dilute
82,3 cm
of
the concentrated hydrochloric acid with density
g/cm
the
distilled water in a measured flask with a capacity of 1000 cm
to
a tag.
Preparation
of solution of iodine of molar concentration
mol/dm
Weigh
4,10 g of iodine in a glass for weighing with a cover, a plastic
spoon transfer to a measured flask with a capacity of 1000 cm
,
add 25 cm
of
the water solution containing 20 g of iodide potassium carefully mix
before full dissolution of iodine and bring the volume of solution
the distilled water to 1000 cm
and
vigorously shake up. Correction coefficient of solution of iodine
establish at least 1 time in 10 days on solution the standard caption
of thiosulphate of sodium of molar concentration
mol/dm
according
to requirementsof
GOST 25794.2. Solution is stored in ware from dark glass with are
polished stopper
at
the room temperature.
Preparation of solution of a hydroxide of sodium of molar concentration mol/dm Dissolve 40,00 g of a hydroxide of sodium in the distilled water in a measured flask with a capacity of 1000 cm and bring volume the distilled water to a tag.
Potassium
bichromate solution preparation of molar concentration
mol/dm
Dissolve 0,317 g of bichromate of potassium in the distilled water and bring the volume of solution the distilled water to 200 cm .
Sodium thiosulphate solution preparation of molar concentration mol/dm
Dissolve
8,00 g of thiosulphate of sodium (
)
in 100 smsvezheprokipyachenny
waters,
add 3 cm
of
isobutyl alcohol, carefully mix and bring the distilled water to 1000
cm
.
The correction coefficient of solution of thiosulphate of sodium is
established in 10 days by solution of bichromate of potassium of
molar concentration of 0,0323 mol/dm
with
correction coefficient 1,0 in accordance with GOST25794.2.
Solution is stored in ware from dark glass with a prishlifovanny
stopper at the room temperature.
Starch solution preparation with a mass fraction of 1% Pound 1 g of starch in a porcelain mortar from 25 cm of the distilled water and pour in the received starched milk in 74 cm of the boiling water.
Preparation of initial solutions of granulated sugar and refined sugar Initial solutions of granulated sugar and refined sugar are prepared. Preparation of initial solution of raw sugar Weigh 20 g of raw sugar with a margin error of ±0,01 g, dissolve the distilled water in a measured flask with a capacity of 100 cm . At continuous hashing add 15 cm of solution of neutral acetic lead to solution( ) mass fraction of 10%. Flask contents are mixed carefully and left for some minutes. After that for removal of excess of acetic lead add 15 cm of solution of disubstituted phosphorly sodium ( ) mass fraction of 10%. Bring volume the distilled water to a tag, shake up and filter via the paper filter.
4.4 Technique of tests of a product
4.4.1 Carrying out test for determination of chromaticity
Weigh 100 g of sugar with a margin error of ±0,1 g and place in a flask with a capacity of 250 cm . Then in a flask pour 100 cm of the distilled water and agitation of a flask dissolve sugar. Size rn the distilled water has to make 7,0±0,2. If necessary rn waters establish the demanded size by means of a hydroxide of sodium or hydrochloric acid.
For faster dissolution of sugar the flask is placed in a water bath with the temperature about 50 °C. Duration of dissolution should not exceed 30 min. Solution is cooled to 20 °C, having placed a flask in the thermostat or on a water bath, and filter under vacuum via the membrane or glass filter. The first portions of a filtrate reject.
Filtering of solution via the paper filter is allowed. Thus to solution of sugar add diatomaceous earth or perlite at the rate of 1% to the mass of solids of solution.
In the filtered solution determine by the refractometer a mass fraction of solids. According to the table given in appendix A depending on a mass fraction of solids find work of a mass fraction of solids of sugar solution on value of its density. Before measurement to a ditch three times rinse with the studied solution then fill in solution in a ditch and by a photometer measure its optical density. Measurements are taken by three times.
4.4.2Conduction the test for sucrose definitions
In a unelected cup weigh 26 g of sugar with a margin error of ±0,001 g (refined sugar previously quickly crush in a porcelain mortar), dissolve in the small portions of the warm distilled water and by means of a funnel transfer to a pure dry measured flask with a capacity of 100 cm . Sugar is dissolved easy rotation of a flask.
At test of raw sugar in a measured flask add to solution on drops lead vinegar (no more than 4 cm ) until the deposit, or 5-10 cm of solution of the main sulfate of aluminum drops out.
Then add the distilled water (surely rinsing a flask mouth) in such volume that the level of solution did not reach 20 mm to a tag to a flask.
The flask with solution is placed in the thermostat for 15 min. for achievement of temperature of (20,0±0,1) °C.
Internal walls of a mouth of a flask to a tag drain filter paper. The foam formed on a solution surface is deleted with a drop of ethyl air. Solution is added the distilled water to a tag by means of a pipette with a thin tip or a syringe for injections. The flask is covered with small hour glass and maintained within 30 min., then closed a pure dry stopper and contents it carefully are mixed easy rotation.
If necessary solution is filtered via the double paper filter, covering a filtering funnel with hour glass in order to avoid evaporation and change of concentration of solution. The first 10 cm of a filtrate merge. Filtering is carried out at the same temperature at which carry out polarization. When using the main sulfate of aluminum contents of a flask are poured out in a dry pure glass, add 1,5-2,0 g of active coal, mixed a glass stick during 30 with and filtered via the double paper filter. Filtering is carried out according to the previous instructions.
Polarimetric to a ditch rinse with the filtered solution and fill so that vials of air were not formed. Integumentary glass should not nestle strongly a head ditches in order to avoid formation of tension which can influence optical rotation of solution.
Polarimetric to a ditch with solution place in a chamber of a saccharimeter and connect to the thermostat in which temperature of (20,0±0,1) °C is maintained.
Take five measurements with a margin error, the equal accuracy of the device, and calculate an arithmetic average value. When using polarimetric ditches 100 mm long value of counting on a scale of a saccharimeter doublean arithmetic average.
When using the automatic polarimeter of test carry out to similarly previous instructions with additional carrying out: - weighings of an empty measured flask with a margin error ±0,001 g; - weighings of a measured flask with sugar solution with a margin error ±0,001 g after 30 min. a vystaivaniye;
- removals of the indication of the polarimeter at empty office for polarimetric ditches;
- removals of indications of the polarimeter at established empty pure and dry polarimetric a ditch;
- determination of temperature of a quartz plate; - removals of indications of the polarimeter at the established quartz plate.
When using the automatic polarimeter polarization is defined taking into account amendments on temperature and volume.
The
polarization corrected on temperature
,
°Z ("sugar" degrees), calculate on a formula
(2),where
- the indication of the polarimeter at established polarimetric a
ditch with solution, °Z;
- the indication of the polarimeter at established empty (without solution) polarimetric a ditch, °Z;
-
the indication of the polarimeter at the established quartz plate,
°Z;
-
the indication of the polarimeter at empty office for polarimetric
ditches,
°Z;
-passport
data
of
a quartz plate;
1,44·10- coefficient;
- temperature of a quartz plate, °C;
20 - air temperature under normal conditions, °C.
The amendment on volume is defined as follows. Calculate the mass of solution , without amendment on weighing to air on a formula
,
(3)
where - the mass of a measured flask with solution;
- mass of an empty measured flask.
The received result is transferred to volume by means of the table given in appendix A.
The amendment on volume is found according to the table given in appendix A.
Example.
Let
=
109,717 g, determine
=100,060
cm
and
the amendment
which
is equal +0,060 °Z
by
the table.
True
polarization
,
°Z, determine by a formula
,
(4) where
- the polarization corrected on temperature, °Z;
- the amendment on the volume, °Z.
Calculations carry out to within 0,01 °Z.
4.4.3 Conduction tests for ashes definition
Weigh
31,3 g of sugar with a margin error of ±0,05 g (refined sugar
previously crush in a mortar), dissolve in the small portions of the
hot distilled water, pour by means of a funnel in a measured flask
with a capacity of 100 cm
,
cool (20,0±0,2) °C up to the temperature, bring volume to a tag the
distilled water and mix. Solution is filtered via the paper ashless
filter, the first 10 smfiltrat
merge.
Before measurement the cell of the conductometer is rinsed
with the studied solution then fill in solution in a cell of the
conductometer and define its specific electric conductivity.
Previously define specific electric conductivity of the distilled
water. The size of specific electric conductivity of the distilled
water has to be no more than 2,0
Cm
/ see. If necessary the demanded size of specific electric
conductivity of water reach it redistillation.
4.4.4 Conduction tests for definition of the reducing substances
Select 20 cm of the initial solution prepared on 4.2.10 that there correspond 2 g of raw sugar, or 50 cm of the initial solution prepared on 4.2.11 that there correspond 10 g of granulated sugar or refined sugar. If the content of the reducing substances in the taken volume of solution of raw sugar exceeds 25 g, select the smaller volume of the solution prepared on 4.2.10.
Solution is placed in a conic flask with a capacity of 250 cm (in the analysis of raw sugar neutralize contents of a flask solution of acetic acid of molar concentration mol/dm in the presence of the indicator of a fenolftalein). The volume of solution is brought the distilled water to 100 cm , add 10 cm of a reactant of Müller, mixed and place a flask with solution in the boiling water bath for 10 min. ± 5 pages. Water level in a bath has to be 2 cm higher than solution level in a conic flask. The flask has to be placed on a support so that it did not concern a bath bottom. The bath has to have such sizes that boiling did not interrupt when placing of a flask in it. After heating the conic flask covered with hour glass in order to avoid oxidation of an oxide of copper with air oxygen quickly is cooled under a stream of cold water without agitation.
After boiling solution has to have bluish-greenish coloring. If solution of orange coloring, experiment are repeated with smaller quantity of a filtrate.
To
the cooled solution add 5 cm
of
solution of acetic acid of molar concentration
mol/dm
and
at once solution of iodine of molar concentration
mol/dm
in
quantity from 20 to 40 cm
(
).
Both solutions add without agitation in order to avoid oxidation of
an oxide of copper
air
oxygen.
The
flask is closed and contents are shaken up before full dissolution of
a deposit, thus solution has the brown coloring caused by excess of
iodine and leave for 2 min. Then add 2 cm
of
solution of starch a mass fraction of 1% and titrut solution of
thiosulphate of sodium of molar concentration
mol/dm
before
disappearance
of
blue coloring of solution.
Carry out control definition, using the same reactants and in the same quantities, but instead of the examinee of solution add the distilled water. Control definition is carried out for each freshly cooked reactant of Müller.
In parallel make experiment without heating, using the same amount of initial solution and the same reactants (after addition of a reactant of Müller solution is left for 10 min.).
4.4.5Conduction tests for definition of the reducing substances
Select 50 cm of the initial solution prepared on 5.2.10 (that there correspond 10 g of granulated sugar or refined sugar), or 15 cm of initial solution (that there correspond 3 g of raw sugar).
Solution is placed in a conic flask, add 50 cm of solution of Offner and the distilled water to the total amount of 100 cm , 2-3 slices of porous ceramics (for uniform boiling), put on a gas torch with a grid and within about 4 min. bring to boiling. Contents of a flask are boiled on slow fire of 5 min., then cooled with fast immersion of a flask in cold water without agitation in order to avoid contact of a deposit of an oxide of copper with air oxygen.
Then add 1 cm of ice acetic acid, surplus (from 10 to 25 cm ) solution of iodine of molar concentration of 0,0323 mol/dm and 15 cm of solution of hydrochloric acid of molar concentration of 1 mol/dm .
The flask is closed and vigorously shaken up, thus solution has to have brown coloring.
The flask is covered with hour glass and left for 2 min. before the end of reaction of iodine with copper. From time to time the flask is shaken up, then add 2 cm of solution of starch with a mass fraction of 1% and titrut excess of solution of iodine solution of thiosulphate of sodium of molar concentration of 0,0323 mol/dm before disappearance of blue coloring.
4.5 Processing of results of tests
4.5.1
Processing
of results for determination of chromaticity
Chromaticity
of sugar
in
terms of optical density is calculated on a formula
,(5)
where
- the value of optical density of solution of sugar measured by the device (arithmetic-mean from three measurements);
- a mass fraction of solids in solution, %;
- density of sugar solution, g/cm ;
- length ditches, see.
Take the received result for the size of chromaticity.
1 units of optical density = 1 units of ICUMSA (International commission on unification of methods of the analysis of sugar).
Chromaticity of sugar can be defined by a photo-electric photometer, without applying a calculation formula, with delivery of its size on a device board. For this purpose after measurement of optical density of sugar solution enter coefficient of factorization which size find depending on a mass fraction of solids in sugar solution from the table given in the appendix B into the COMPUTER of the device.
Indications on a board of the device correspond to the size of chromaticity of the examinee of sugar in terms of optical density
4.5.2 Processing of results for sucrose definition
Mass
fraction of sucrose
,
%, calculate on formulas
- when using saccharimeters
with
maple compensation
;
(6)
- when using saccharimeters with the rotating compensator
,
(7)
Where - arithmetic-mean value of counting on a saccharimeter scale at a measurement temperature;
0,000611; 0,000467 - coefficients;
- solution temperature at measurement, °C;
20 - air temperature under normal conditions, °C.
Mass fraction of sucrose , %, in terms of solid calculate on a formula
,
(8)
where - result of measurements, %;
- a mass fraction of moisture in sugar, %.
Take for final result of test arithmetic-mean results of two parallel definitions, the allowed divergence between which should not exceed 0,05% of a mass fraction of sucrose.
4.5.3 Processing results for ashes definition
Mass fraction of ashes , %, calculate on a formula
,
(9)
where
-
the amendment on specific electric
conductivity
of ashes;
-
specific electric conductivity of the studied solution of
sugar,
Cm/cm;
0,35
- the amendment on specific electric conductivity of water; - specific electric conductivity of the distilled water, Cm / see. In the conductometers graduated as a percentage ashes, numerical value of a mass fraction of ashes is given directly for a device board. In case definition is carried out at a temperature other than 20 °C, the amendment on temperature is entered (appendix A, B).
Value of the amendment on temperature is subtracted from the value received at test test if temperature is above 20 °C and increases if temperature is below 20 °C.
Take for final result of test arithmetic-mean results of two parallel definitions, the allowed divergence between which should not exceed 0,003%.
4.5.4 Processing of resultsfor definition of the reducing substances
At calculation of a mass fraction of the reducing substances accept that 1 cm of solution of iodine (0,0333 mol/dm ) corresponds to 1 mg of the reducing substances.
The
mass fraction of the reducing substances in sugar
,
%, is calculated on a formula
,
(10)
Where - the amount of solution of iodine spent for test, cm ; - the amount of solution of thiosulphate of sodium spent for titration, cm ;
- correction coefficient of solution of iodine;
- correction coefficient of solution of thiosulphate of sodium;
- the sum of amendments on an iodine solution consumption on sucrose restoration (at the rate of 0,2 cm on 1 g), on an iodine solution consumption when determining without heating, on the reducing ability of a reactant of Müller;
100 - recalculation coefficient in percent;
-
mass
of
a hinge plate;
1000
- coefficient of recalculation
of
grams in milligrams.
The sum of amendments
,
cm
,
calculate on a formula
,(11)
where
0,2 - an iodine solution consumption on restoration of 1 g of
sucrose, cm/g;
-
the mass of a hinge plate;
- amount of solution of iodine, cm;
- correction coefficient of solution of iodine;
-
the amount of solution of thiosulphate of sodium spent for titration
at control definition, cm
;
- correction coefficient of solution of thiosulphate of sodium; - the amount of solution of thiosulphate of sodium spent for titration in experience without heating, cm (on 4.3.2).
Take arithmetic-mean value of results of two parallel definitions the divergence between which should not exceed 0,01% in absolute value for final result of test. If the divergence exceeds this size, test repeat. Calculation is carried out to within the second decimal sign. The divergence between the results of definition executed in two different laboratories should not exceed 0,02% in absolute value.
Admissible relative error of result of the analysis of 0,45% at confidential probability 0,95.
The method is applied at emergence of disagreements in an assessment of quality of raw sugar.
4.5.5obrabotka resultsfor definition of the reducing substances
At calculation of a mass fraction of the reducing substances accept that 1 cm of solution of iodine (0,0323 mol/dm ) corresponds to 1 mg of the reducing substances. Mass fraction of the reducing substances , %, calculate on a formula
,(12)
where
-
the excess amount of solution of iodine spent for test, cm
;
- the amount of solution of thiosulphate of sodium spent for titration, cm;
- correction coefficient of solution of iodine;
-
correction coefficient of solution
of
thiosulphate of sodium;
- the amendment on an iodine solution consumption (for 1 g of sucrose it is spent 0,1 cm of solution of iodine);
100 - recalculation coefficient in percent;
- the mass of a hinge plate;
1000 - coefficient of recalculation of grams in milligrams.
The amendment on a consumption of solution of iodine is calculated on a formula
,(13)
where
0,1 - an iodine solution consumption on 1 g of sucrose, cm/g
;
- mass of a hinge plate;
- mass fraction of sucrose, %.
Take arithmetic-mean value of results of two parallel definitions the divergence between which should not exceed 0,01% in absolute value for final result of test. If the divergence exceeds this size, test repeat.
Calculation is carried out to within the second decimal sign. The divergence between the results of definition executed in two different laboratories should not exceed 0,02% in absolute value. An admissible relative error of result of the analysis of 0,45% at confidential probability 0,95.
The method is applied at emergence of disagreements in an assessment of quality of granulated sugar and refined sugar.
Selection
according to GOST 12574-93
Equipment: Scales
laboratory general purpose of the 4th class of accuracy with the
greatest limit of weighing of 500 g - in accordance with GOST24104. The
thermostat the liquid, allowing to maintain temperature with a
deviation from a preset value ±0,1 °C.
Order
of carrying out test: Weigh
31,3 g of sugar with a margin error of ±0,05 g (sugar previously
crush lump sugar in a mortar), dissolve in the small portions of the
hot distilled water, pour by means of a funnel in dimensional
cooling (20,0±0,2) °C up to the temperature, bring volume to a tag
the distilled water and mix. The solution via the paper ashless
filter, the first 10 cm of a filtrate merge
Before
measurement the cell of the conductometer is rinsed with the studied
solution then fill in solution in a cell of the conductometer and
define its specific electric conductivity. Previously define
specific electric conductivity of the distilled water. The size of
specific electric conductivity of the distilled water has to be not
bolee2,0 Cm / see. If necessary the demanded size of specific
electric conductivity of water reach it redistillation.
Processing
of results:
Mass
fraction of ashes, %, calculate on a formula
,
where
-
the amendment on specific electric conductivity of ashes;
-
specific electric conductivity of the studied solution of sugar,
Cm/cm;
0,35 amendment on specific electric conductivity of
water;
- specific electric conductivity of the distilled water,
Cm / see. In the conductometers graduated as a percentage ashes,
numerical value of a mass fraction of ashes is given directly for a
device board. In case definition is carried out at a temperature,
excellent from 20 Value of the amendment on temperature is
subtracted from the value received at test test if temperature is
above 20 °C and increases if temperature is below 20 °C.
the
°C, is entered the amendment on temperature (appendix A, B).
Take
for final result of test arithmetic-mean results of two parallel
definitions, the allowed divergence between which should not exceed
0,003%
Conclusion
White sugar has to conform to the requirements established by standard and technical documentation, and also to hygienic requirements to a nutrition value and safety of foodstuff and food staples.
Quality and safety of foodstuff, materials and products are provided by means of:
- applications of measures of state regulation in the field of ensuring quality and safety of foodstuff, materials and products;
- carrying out by citizens, including individual entrepreneurs, and the legal entities which are carrying out activities for production and a turn of foodstuff, materials and products, organizational, agrochemical, veterinary, technological, technical, sanitary and anti-epidemic and phytosanitary actions for implementation of requirements of normative documents to foodstuff, materials and products, conditions of their production, storage, transportations and realization;
- carrying out production control over quality and safety of foodstuff, materials and products, conditions of their production, storage, transportations and realization, introduction of control systems of quality of foodstuff, materials and products;
- applications of measures for suppression of violations of the Republican law, including requirements of normative documents, and also measures of civil, administrative and criminal liability to the persons guilty of commission of the specified violations.
List of references
1. GOST 31361-2008 "Sugar-white. Specifications"
2. GOST P 53396-2009 "Sugar-white. Specifications"
3. GOST 12569-99 "Sugar. Acceptance procedures and methods of sampling"
4. GOST 12570-98 "Sugar. Method of definition of moisture and solids"
5. GOST 12571-98 "Sugar. Sucrose definition method"
6. GOST 12572-93 "Granulated sugar and refined sugar. Methods of determination of chromaticity"
7. GOST 12573-67 "Sugar. Method of definition ferroprimesy"
8. GOST 12574-93 "Granulated sugar and refined sugar. Ashes definition methods"
9. GOST 12575-2001 "Sugar. Methods of definition of the reducing substances"
10. GOST 12576-89 "Sugar. Methods of determination of appearance, smell, taste and purity of solution"
11. GOST 12579-67 "Granulated sugar and refined sugar. Method of definition of particle size distribution"
12. GOST 26521-85 "Granulated sugar and refined sugar. Methods of determination of net weight"
13. GOST 26884 - 2002 "Products of sugar industry. Terms and definitions"
14. GOST 26927-86 "Raw materials and foodstuff. Mercury definition method"
15. GOST 26929-86 "Raw materials and foodstuff. Preparation of tests. A mineralization for definition of toxic elements"
16. GOST 26930-86 "Raw materials and foodstuff. Arsenic definition method"
17. GOST 26931-86 "Raw materials and foodstuff. Copper definition methods"
18. GOST 26932-86 "Raw materials and foodstuff. Lead definition method"
19. GOST 26933-86 "Raw materials in foodstuff. Cadmium definition method"
20. GOST 26934-86 "Raw materials and foodstuff. Zinc definition method"
21. GOST 26968-86 "the Granulated sugar refined. Methods of the microbiological analysis"
22. Bugaenko I. F. Processing of raw cane sugar. - M.: Teller, 1997. - S. 31.
23. The golybin V. A., Chernyaeva L. A., Isaev A. K. Microbiological contamination of raw sugar // Sugar. - 2001. - No. 3. - S. 12.
24. Deminski F. A. Production of refined sugar. - M.: Food industry, 1974. - P. 40
25. Dmitrichenko M. I., Pilipenko T. V. commodity research and examination of dietary fats, milk and dairy products: Proc. allowance. - SPb.: Peter, 2004. - 352 C
26. Dracheva S. T. Theoretical basis of commodity research of food products. - M.: Economics, 1996. - S