# Method of determination of acetic acid concentration

FIELD: chemical industry; methods of determination of acetic acid concentration.

SUBSTANCE: the invention is pertaining to the field of chemical industry, in particular, to the method of determination of acetic acid concentration in a broad band of temperatures. The technical result is an increased accuracy at determination of concentration of acetic acid within the range of temperatures from 0° up to 40°C. The offered method allows using the linear interpolation to determine dependence of density on the concentration and the temperature in 1°C within the range of temperatures from 0°C up to 40°C according to the known dependence of density from concentration over the range from 0 up to 100 % and on the temperature - from 0°C up to 40°C in 5; 10°C. Then they homogenize the solution and determine the temperature of the solution in the pressure tank with accuracy 0.1°C and the density. At the integer values of the temperature using the received dependence determine two values of density that are the most close to the experimental values and two values of concentration corresponding to them and determine the first derivative from concentration according to the density. If |dc/dp | ≤ 3.3*10,^{} the concentration is determined by the linear interpolation method according to the received dependence of density on concentration with accuracy up to 0.1 %. If |dc/dp |> 3.3*10^{3}, then into pressure tank inject water in a such amount that to get into the zone of |dc/dp | <3.3*10^{3} for determination of concentration of the acetic acid. In the case of non-integral values of the temperature it is necessary to conduct the following operations: for the most close to the experimental integer value of the temperature select two values of density the most close to the experimental value of density and corresponding to them two values of concentration. Using the received dependence of the density on the temperature find two values of density at the temperature of the experiment and determine the first derivative from concentration on the density, and then the operations are iterated as for the integer value of the temperature.

EFFECT: the invention ensures an increased accuracy at determination of concentration of acetic acid within the range of temperatures from 0° up to 40°C.

5 ex, 4 tbl, 3 dwg

The invention relates to the field of chemistry, in particular for determining the concentration of acetic acid in a wide temperature range.

There is a method of determining the concentration of acetic acid titration method /TU 9182-022-0334586-03. Acetic acid food, Moscow, p.16/.

The method is as follows.

Take the sample test solution, dilute with water. Further titration with sodium hydroxide solution with phenolphthalein indicator until the transition of color from colorless to purple. Then about the calculation of the mass fraction of acetic acid in% /X_{1}/ by the formula

X_{1}=(V*0,6005*100):m-1.3 X_{2},

where V is the volume of sodium hydroxide solution of concentration exactly 1 mol/DM^{3}used for titration, cm^{3},

m is the sample of the analyzed solution, g,

X_{2}- mass fraction of formic acid, %.

The disadvantages of the method are:

- availability of sophisticated equipment,

- difficulty making m sodium hydroxide solution,

- the use of sodium hydroxide only the qualification of "chemically pure",

- complexity methods for determining the mass fraction of formic acid.

There is also known a method of determining the concentration of acetic acid, taken as a prototype /TU 9182-022-00334586-03. Acetic acid food, Moscow, p.16-18, p.24-25/.

The method is as follows.

Take a sample of 200 g of test solution concentration of 70%; 80% and diluted with the same amount of water. Bring the temperature up to 20°and pour the solution into the cylinder. Determine the temperature of the solution, then a hydrometer to determine the density and again measure the temperature of the solution. Then take the average of the temperature before and after the density measurement. In a known density dependence of the concentration at 20° (chemist's Handbook, T. W, s-578; M - L., 1964) determine the concentration of the solution, dual and get the original concentration.

The disadvantages of the method are:

- the inability to determine the concentration of acetic acid at temperatures different from 20°C;

- low accuracy of determination of concentration, as the accuracy of bringing the temperature up to 20°With approximately 1°C

- long analysis time due to taking a sample and bring the temperature of the dilute solution up to 20°C;

- change the structure of the polymer solution upon dilution with water, which also affects the accuracy of determination of concentration.

The objective of the invention is to improve the accuracy in determining the concentration of acetic acid in the range from 0 to 100% in the temperature range from 0 to 40°C.

This object is achieved in that in the method of determining the concentration of acetic acid to the slots,
including the determination of the density of the solution and the establishment of proper concentration, according to the invention, determine the density dependence on concentration and temperature through 1°in the range from 0 to 40°With the method of linear interpolation on a known density dependence of the concentration in the range from 0 to 100 wt.% and temperature from 0 to 40°5; 10°after homogenization of the solution determine the temperature of a solution of acetic acid in a pressure vessel with an accuracy of 0.1°and density, for integer values of temperature are two density values, the closest to the experimental, and two concentration values, appropriate, determine the first derivative of the concentration density and if |dc/dp|≤3,3·10^{3}the concentration of acetic acid is determined by the method of linear interpolation of the density dependence of the concentration at the temperature of the experience with an accuracy of 0.1% and if |dc/dp|>3,3·10^{3}in pressure vessel enter the water in such a quantity to get in the zone |dc/dp|≤3,3·10^{3}to determine the concentration of acetic acid after dilution and calculation of the initial concentration, based on the amount of added water; in case of non-integer values of the temperature, do the following: for the most close to the experimental a values the temperature are two adjacent values of density,
the closest to the experimental and the corresponding concentration values, on the dependence of density on temperature for two values of concentration are two values of the density at the temperature of the experiment and determine the first derivative of the concentration density, and then the operation is repeated for the whole temperature values.

This method allows you to identify the zone concentrations /60-85%/, in which the dependence of density on temperature is almost linear, which allows to determine the concentration with high accuracy.

Figure 1 shows the dependence of the density of aqueous solutions of acetic acid concentration at temperatures of 0, 20, 30°C.

Figure 2 shows the concentration dependence of the first derivative of the concentration density at 20°C: dc/dp=f(C).

Figure 3 shows the concentration dependence of the absolute value of the first derivative of the density on temperature |dp/dT|=f(C).

The method is as follows.

Determine the density dependence on concentration and temperature through 1°in the temperature range from 0 to 40°With the method of linear interpolation on a known density dependence of the solution concentration in the range from 0 to 100% in 1% and a temperature in the range from 0 to 40°5; 10°C.

In the whole range of temperatures depending the density of the concentration passes through a maximum at concentrations 76-83% (figure 1). This means that the first derivative of density concentration becomes 0 and to determine the concentration requires the introduction of water. To simplify the following table segments:

table 1.1 concentrations of 5-7% and temperatures of 10-30°C;

table 1.2 for the concentration of 68-70% and temperatures 0-22°C;

table 1.3 for the concentration of 79-81% and temperatures 0-22°C;

table 1.4 concentration of 92-94% and temperatures of 10-30°C.

Further implementation of the method discussed in the examples at various densities and temperatures.

Example 1.

In the pressure tank with a capacity of 5 m^{3}containing 4700 DM^{3}an aqueous solution of acetic acid, homogenize it by circulation on the circuit: discharge capacity of the pump, directly in the tank determine the temperature of the solution 19,0°and in the selected sample density is determined using the hydrometer 1,0690. Then according to the density dependence of the concentration and temperature (1.2) are at a temperature of 19°With two density values, the closest to the experimental 1,06874 and 1,06914, and two concentration values that they correspond to 68, and 69%. Calculate the value of the first derivative of the concentration density dc/dp:

dc/dp=(69-68):(1,06914-1,06874)=2,5·10^{3}

The first derivative of the concentration density of less than 3.3·10^{3}. From figure 2 it follows that h is about when it is <
3,3·10^{3}you can determine the concentration, if |dc/dp|>3,3·10^{3}then the derivative is increasing rapidly, tending to infinity, which does not allow to determine the concentration.

By the method of linear interpolation of the dependence of the concentration on the density at T=19°using the found value of dc/dp, find the concentration of:

C=68+2,5·10^{3}·(1,0690-1,06874)=68,65˜68,6%.

Example 2.

In the pressure vessel homogenized 4800 DM^{3}solution of acetic acid. Directly in the tank determines the temperature of 15.7°With, in the selected sample density is determined using the hydrometer 1,0725. In 1.2 are two density values, the closest to the experimental ones for the whole temperature value 16°S: 1,07196 and 1,07226, and two concentration values, they are relevant: 69, and 70%. By the method of linear interpolation of the dependence of density on temperature for the two concentrations, using the values of the derivative dp/dT, is given in 1.2, calculate the density at non-integer values of temperature:

69%: p=1,07196+/-0,00094/*/15,7-16/=1,07224

70%: p=1,07226+/-0,00094/*/15,7-16/=1,07254.

Calculate the value of the first derivative of the concentration density at a temperature of 15.7°With:

dc/dp=(70-69):(1,07254-1,07224)=3,3·10^{3}.

dc/dp=3.3V·10^{3}. The concentration calculated by the method of linear interpolation of the dependence of the concentration from the lotnosti at a temperature of 15.7°
With:

C=69+3.3V·10^{3}/1,0725-1,07224/=69,89˜69,9%.

From figure 3 it follows that the absolute value of the derivative of the density on temperature |dp/dT| nonlinear increases with increasing concentration, reaching a limiting value with >90%. Figure 3 shows the absolute error in the determination of this derivative with 95%confidence probability. In the concentration range of 60-80% relative error does not exceed 1.9%.

Example 3.

In discharge capacity after homogenization receive 4350 DM^{3}solution of acetic acid. Determine the temperature directly in the pressure capacity of 12.2°With, in the selected sample density is determined 1,0725. On tabl find two density values, the closest to the experimental ones for the whole temperature value 12°S: 1,07776 and 1,07762, and two concentration values, corresponding to 80, and 81%. Analogously to example 2 by the method of linear interpolation expect two density values for non-integer values of temperature and two concentrations:

80%: p=1,07756

81%: p=1,07741.

Calculate the value of the first derivative of the concentration density at temperatures of experience:

dc/dp=(81-80):(1,07741-1,07756)=-6,6·10^{3}; |dc/dp|>3,3·10^{3}.

In the pressure vessel is injected 660 DM^{3}water, homogenize the solution, determine the temperature of 13.2°C, density 1,0748. On the dependence of the density on the concentration and the fact is that the temperature /1.2/ find the two values of the density at a temperature of 13°
With the closest experimental 1,07474 and 1,07508, and two concentration values, corresponding to 69, and 70%. Analogously to example 2 find the two values of the density at the temperature of the experience: 13,2°With:

69%: p=1,07456

70%: p=1,07490.

Calculate the value of dc/dp at 13,2°With:

dc/dp=(70-69):(1,07490-1,07456)=2,9·10^{3}:|dc/dp|<3,3·10^{3}.

By the method of linear interpolation of the dependence of the concentration on the density determine the concentration of:

C=69+2,92·10^{3}/1,0748-1,07456/=69,71˜69.7 percent.

Then calculate the concentration prior to the introduction of water. It is of 79.5%.

Example 4.

In the pressure tank with a capacity of 1000 DM^{3}prepare 970 kg of a solution of vinegar. Directly in the tank determines the temperature of 21.3°With, in the selected sample density is determined 1,0062.

In table 1.1. when the closest whole temperature value 21°To find two values of the density closest to the experimental 1,00522 and 1,00662, and the corresponding values of the concentrations of 5 and 6%.

By the method of linear interpolation of the dependence of density on temperature calculated two density values for non-integer values of temperature and two concentrations:

5%: p=1,00522+/-0,00028/*(21,3-21)=1,00514

6%: p=1,00622+/-0,00028/*(21,3-21)=1,00654

Next, calculate the value of the first derivative of the concentration density at non-integer values of temperature:

dc/dp=6-5):(1,00654-1,00514)=714;
|dc/dp|<3.3·10^{3}.

By the method of linear interpolation of the dependence of the concentration on the density calculate the concentration:

C=5+714/1,0062-1,00513/=5,76˜5,8%.

Example 5.

In railway tank having a capacity of 73 m^{3}containing 66,6 tons of concentrated acetic acid, water is supplied, then the solution is homogenized, determine the temperature of 15.0°and density 1,0683.

According to the table. 1.4 find the two values of the density closest to the experimentally found at a temperature of 15.0°S: 1,0690 and 1,0680, and two concentration values, corresponding to 92, and 93%. Calculate the value of the first derivative of the concentration density:

dc/dp=(93-92):(1,0680-1,0690)=-1,0·10^{3}; [dc/dp]<3,3·10^{3}.

Calculate the concentration of the dependence of the concentration from the absorbance at 15,0°With the method of linear interpolation:

C=92+/-1.0·10^{3}/1,0680-1,0690/=92,7%.

This method allows to determine with high accuracy any concentration of acetic acid in a wide temperature range.

Table 1.1. Density of aqueous solutions of acetic acid, depending on temperature and concentration. | ||||||

Temperature, °C. | Density and dp/dT for a given concentration | |||||

5% | 7% | |||||

P | dp/dT | P | dp/dT | P | dp/dT | |

0 | 1,00880 | 1,01060 | 1,01240 | |||

10 | 1,00760 | 1,00920 | 1,01080 | |||

11 | 1,00740 | 1,00898 | 1,01056 | |||

12 | 1,00720 | -0,00020 | 1,00876 | -0,00022 | 1,01032 | -0,00024 |

13 | 1,00700 | 1,00854 | 1,01008 | |||

14 | 1,00680 | 1,00832 | 1,00984 | |||

15 | 1,00660 | 1,00810 | 1,00960 | |||

16 | 1,00638 | 1,00786 | 1,00934 | |||

17 | 1,00616 | 1,00762 | 1,00908 | |||

18 | 1,00594 | -0,00022 | 1,00738 | 0,00024 | 1,00882 | -0,00026 |

19 | 1,00572 | 1,00714 | 1,00856 | |||

20 | 1,00550 | 1,00690 | 1,00830 | |||

21 | 1,00522 | 1,00662 | 1,00800 | |||

22 | 1,00494 | 1,00634 | 1,00770 | |||

23 | 1,00466 | -0,00028 | 1,00606 | -0,00028 | 1,00740 | -0,00030 |

24 | 1,00438 | 1,00578 | 1,00710 | |||

25 | 1,00410 | 1,00550 | 1,00680 | |||

26 | 1,00376 | 1,00514 | 1,00644 | |||

27 | 1,00342 | 1,00478 | 1,00608 | |||

28 | 1,00308 | -0,00034 | 1,00442 | -0,00036 | 1,00572 | -0,00036 |

29 | 1,00274 | 1,00406 | 1,00536 | |||

30 | 1,00240 | 1,00370 | 1,00500 |

Table 1.2. Density of aqueous solutions of acetic acid, depending on temperature and concentration. | ||||||

Temperature, °C. | Density and dp/dT for a given concentration | |||||

68% | 69% | 70% | ||||

P | dp/dT | P | dp/dT | P | dp/dT | |

0 | 1,08600 | 1,08650 | 1,08690 | |||

1 | 1,08511 | 1,08560 | 1,08600 | |||

2 | 1,08422 | 1,08470 | 1,08510 | |||

3 | 1,08333 | 1,08420 | ||||

4 | 1,08244 | 1,08290 | 1,08330 | |||

5 | 1,08155 | -0,00089 | 1,08120 | -0,00090 | 1,08240 | -0,00090 |

6 | 1,08066 | 1,08110 | 1,08150 | |||

7 | 1,07977 | 1,08020 | 1,08060 | |||

In | 1,07888 | 1,07930 | 1,07970 | |||

9 | 1,0,7799 | 1,07840 | 1,07880 | |||

10 | 1,07710 | 1,07750 | 1,07790 | |||

11 | 1,07618 | 1,07658 | 1,07696 | |||

12 | 1,07525 | 1,07566 | 1,07602 | |||

13 | 1,07434 | -0,00092 | 1,07474 | -0,00092 | 1,07508 | -0,00094 |

14 | 1,07342 | 1,07382 | 1,07414 | |||

15 | 1,07250 | 1,07290 | 1,07320 | |||

16 | 1,07156 | 1,07196 | 1,07226 | |||

17 | 1,07062 | 1,07102 | 1,07132 | |||

18 | 1,06968 | -0,00094 | 1,07008 | -0,00094 | 1,07038 | -0,00094 |

19 | 1,06874 | 1,06914 | 1,06944 | |||

20 | 1,06780 | 1,06820 | 1,06850 | |||

21 | 1,06686 | 1,06724 | 1,06754 | |||

22 | 1,06592 | -0,00094 | 1,06628 | 1,06658 |

Table 1.3. Density of aqueous solutions of acetic acid, depending on temperature and concentration. | ||||||

Temperature,° | Density and dp/dT for a given concentration | |||||

79% | 80% | 81% | ||||

P | dp/dT | P | dp/dT | P | dp/dT | |

0 | 1,08940 | 1,08950 | 1,08950 | |||

1 | 1,08844 | 1,08853 | 1,08852 | |||

2 | 1,08748 | 1,08756 | 1,08754 | |||

3 | 1,08652 | 1,08652 | 1,08656 | |||

4 | 1,08556 | 1,08556 | 1,08558 | |||

5 | 1,08460 | -0,00096 | 1,08456 | -0,00097 | 1,08460 | -0,00098 |

6 | 1,08364 | 1,08368 | 1,08362 | |||

7 | 1,08268 | 1,08271 | 1,08264 | |||

8 | 1,08172 | 1,08172 | 1,08166 | |||

9 | 1,08076 | 1,08077 | 1,08068 | |||

Ȁ | ||||||

10 | 1,07980 | 1,07980 | 1,07970 | |||

11 | 1,07878 | 1,07878 | 1,07866 | |||

12 | 1,07776 | -0,00102 | 1,07776 | -0,00102 | 1,07762 | -0,00104 |

13 | 1,07674 | 1,07674 | 1,07762 | |||

14 | 1,07572 | 1,07674 | 1,07658 | |||

15 | 1,07470 | 1,07470 | 1,07450 | |||

16 | 1,07376 | 1,07376 | 1,07358 | |||

17 | 1,07282 | -0,00094 | 1,07282 | -0,00094 | 1,07266 | -0,00092 |

18 | 1,07188 | 1,07188 | 1,07174 | |||

19 | 1,07094 | 1,07984 | 1,07082 | |||

20 | 1,07000 | 1,07000 | 1,06990 | |||

21 | 1,06896 | 1,06894 | 1,06884 | |||

22 | 1,06792 | -0,00104 | 1,06788 | 1,06778 |

Table 1.4. Density of aqueous solutions of acetic acid, depending on the temperature the s and concentration. |
|||||||

Temperature, °C. | Density and dp/dT for a given concentration | ||||||

92% | 93% | 94% | |||||

P | dp/dT | P | dp/dT | P | dp/dT | ||

K) | 1,07490 | 1,07390 | 1,07270 | ||||

11 | 1,07372 | 1,07272 | 1,07150 | ||||

12 | 1,07254 | -0,00118 | 1,07154 | -0,00118 | 1,07030 | -0,00120 | |

13 | 1,07136 | 1,07036 | 1,06910 | ||||

14 | 1,07018 | 1,06918 | 1,06790 | ||||

15 | 1,06900 | 1,06800 | 1,06670 | ||||

16 | 1,06806 | -0,00094 | 1,06704 | -0,00096 | 1,06574 | -0,00096 | |

17 | 1,06712 | 1,06608 | 1,06478 | ||||

18 | 1,06618 | 1,06512 | 1,06382 | ||||

19 | 1,06524 | 1,06416 | 1,06286 | ||||

20 | 1,06430 | 1,06320 | 1,06190 | ||||

21 | 1,06318 | 1,06210 | 1,06080 | ||||

22 | 1,06206 | -0,00112 | 1,06100 | -0,00110 | 1,05970 | -0,00110 | |

23 | 1,06094 | 1,05990 | 1,05860 | ||||

24 | 1,05982 | 1,05880 | 1,05750 | ||||

25 | 1,05870 | 1,05770 | 1,05640 | ||||

26 | 1,05756 | 1,05652 | 1,05524 | ||||

27 | 1,05642 | -0,00114 | 1,05534 | -0,00118 | 1,05408 | -0,00116 | |

28 | 1,05528 | 1,05416 | 1,05292 | ||||

29 | 1,05414 | 1,05298 | 1,05176 | ||||

30 | 1,05300 | 1,05180 | 1,05060 |

The method of determining the concentration of acetic acid, comprising the determination of the density of the solution and the establishment of proper concentration, characterized in that to determine the dependence of the density of the solution concentration and temperature through 1°in the range from 0 to 40°With the method of linear interpolation on a known density dependence of the solution concentration in the range from 0 to 100 wt.% and temperature from 0 to 40°after homogenization of the solution determine the temperature of a solution of acetic acid in a pressure vessel with an accuracy of 0.1°and density, for integer values of temperature are obtained according to the two values of the density closest to the experimental, and two concentration values, appropriate, determine the first derivative of the concentration density and, ifthe concentration of acetic acid is determined by the method of linear interpolation on the obtained dependence of the concentration on the density with an accuracy of 0.1%, and ifin the pressure vessel enter the water in such a quantity to get in the zoneto the op what edeline the acetic acid concentration after dilution and calculation of the initial concentration, based on the amount of added water; in case of non-integer values of the temperature, do the following: for closest to the whole experimental temperature values are two density values, the closest to the experimental, and the corresponding two values of concentration, the obtained dependence of density on temperature for two values of concentration are two values of the density at the temperature of the experiment and determine the first derivative of the concentration density, and then the operation is repeated for the whole temperature values.

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2 dwg

FIELD: technology for determining moisture load of solid materials, possible use for construction, chemical and other industries.

SUBSTANCE: UHF method for determining moisture load of solid materials on basis of Brewster angle includes positioning researched material into high-frequency electromagnetic field with following registration of parameters alternation, characterizing high-frequency emission. Ring-shaped multi-slit antenna with electronic-controlled direction diagram excites electromagnetic wave, falling onto dielectric material. Direction diagram inclination angle is measured until moment, at which minimal power of reflected wave is detected, wave length of UHF generator is determined and Brewster angle is calculated. Then on basis of normalized mathematical formulae moisture load value of surface layer of W_{s} is calculated for measured material. Further, power of refracted wave is stabilized by changing power of falling wave, temperature of subject material T_{1} is measured, and after given time span - temperature T_{2} and moisture level are determined for volume of material from given mathematical relation. Device for realization of given method includes UHF generator, UHF detector, wave-guiding Y-circulator, input shoulder of which has generator block controlled by voltage, attenuator, controlled by central microprocessor unit, UHF watt-meter with output to central microprocessor unit device for controlling and stabilization of output power, diode pulse modulator and video pulse generator, controlled by central microprocessor unit, peak detector. First output shoulder of Y-circulator has absorbing synchronized load, and second output shoulder has complex cone antenna, consisting of emitting portion in form of ring-shaped multi-slit antenna and cone-shaped receipt portion, to which gate is connected as well as second UHF watt-meter, connected to extreme digital controller for searching and indication of power minimum of returned wave and resonator indicator of wave meter. UHF generator is powered by central microprocessor unit controlled power block, video pulse counter is connected to digital wave meter, and thermal pairs block is connected to central microprocessor unit device.

EFFECT: increased sensitivity, increased precision of measurement of moisture load of surface layer, expanded functional capabilities due to additional determination of integral moisture load on basis of interaction volume and decreased parasitic UHF emission.

2 cl, 3 dwg

FIELD: chemical industry; methods of determination of acetic acid concentration.

SUBSTANCE: the invention is pertaining to the field of chemical industry, in particular, to the method of determination of acetic acid concentration in a broad band of temperatures. The technical result is an increased accuracy at determination of concentration of acetic acid within the range of temperatures from 0° up to 40°C. The offered method allows using the linear interpolation to determine dependence of density on the concentration and the temperature in 1°C within the range of temperatures from 0°C up to 40°C according to the known dependence of density from concentration over the range from 0 up to 100 % and on the temperature - from 0°C up to 40°C in 5; 10°C. Then they homogenize the solution and determine the temperature of the solution in the pressure tank with accuracy 0.1°C and the density. At the integer values of the temperature using the received dependence determine two values of density that are the most close to the experimental values and two values of concentration corresponding to them and determine the first derivative from concentration according to the density. If |dc/dp | ≤ 3.3*10,^{} the concentration is determined by the linear interpolation method according to the received dependence of density on concentration with accuracy up to 0.1 %. If |dc/dp |> 3.3*10^{3}, then into pressure tank inject water in a such amount that to get into the zone of |dc/dp | <3.3*10^{3} for determination of concentration of the acetic acid. In the case of non-integral values of the temperature it is necessary to conduct the following operations: for the most close to the experimental integer value of the temperature select two values of density the most close to the experimental value of density and corresponding to them two values of concentration. Using the received dependence of the density on the temperature find two values of density at the temperature of the experiment and determine the first derivative from concentration on the density, and then the operations are iterated as for the integer value of the temperature.

EFFECT: the invention ensures an increased accuracy at determination of concentration of acetic acid within the range of temperatures from 0° up to 40°C.

5 ex, 4 tbl, 3 dwg

FIELD: possible use for determining water presence level in product of oil wells.

SUBSTANCE: method for measuring mass concentration of water in water-oil-gas mixture includes taking of a sample of water-oil-gas mixture in hermetic cylinder-shaped vessel with given volume V and height H and measurement of hydrostatic pressure P_{1} at fixed values of temperature T and pressure P_{a} in aforementioned vessel. After measuring of hydrostatic pressure volume of vessel hollow is decreased until full solution of gas and hydrostatic pressure P_{2} is measured, and mass concentration of water W in water-oil-gas mixture is determined in accordance to mathematical expression , where g - free fall acceleration.

EFFECT: improved precision of measurements of mass concentration of water in liquid due to prevented influence of gas separation.

1 dwg

FIELD: the invention may be used for automated control of humidity of soil, seeds of grain cultures and other granular materials.

SUBSTANCE: the arrangement for measuring humidity of granular materials has a high frequency T-piece connected with its first branch pipe with the input of a stroboscopic reference arrangement, its synchronizing input is switched to the first output of a synchronizer; another branch pipe of the high frequency T-piece is connected to the output of a generator of outgoing impulses, its launching input is switched to the second output of the synchronizer; the third branch pipe of the high frequency T-piece is connected through a connecting cable with a primary measuring transducer. The output of the stroboscopic reference arrangement is attached to a regulated threshold arrangement whose output is switched to the inputs of the first and the second blocks of detecting impulse fronts; the output of the first detecting block is connected with launching inputs of a timer and a program-time arrangement and the output of the second detecting block - with the input of the initial installation of the program-time arrangement and a stopping input of the timer whose output is connected to a calculating arrangement with an indicator; the output of the generator of outgoing impulses is switched to a peak detector of impulses with memory connected with its output to the first input of a multiplier whose output is connected with the controlling input of the regulated threshold arrangement and the second input is switched to the output of the program-time arrangement.

EFFECT: allows automated measurement and control of humidity of granular materials.

2 dwg

FIELD: the invention refers to measuring technique and may be used for example in industry, medicine, agriculture for definition of humidity of grain in a flow at its drying.

SUBSTANCE: a sensor-moisture meter for a drain drying machine has two parallel metallic plates 1 forming a condenser and a measuring block transforming values of condenser capacities into an analog signal according to the specified grain culture. The metallic plates 1 provided with dielectric columns 2 fastening it to the body of the grain drying machine in the grain flow subjected to drying with the aid of a cover 3 to the body 4 which in its turn is fixed to a flange 6 with a washer. At that the values of grain humidity are defined in accordance with the meaning of the analog signal of the sensor-moisture meter according to the formula: V_{i }= K (W_{I} - W_{MIN}), where V_{i }- a current value of the analog signal, B; K - a coefficient of transferring humidity into an analog signal, B/%; W_{I} - a current value of humidity of a measured culture, %; W_{MIN} -a minimal value of humidity of a measured culture, %. The sensor- moisture meter is characterized with correlation of the width of the "B" flow of grain subjected to drying to the width of the " b" coverage of the flow of grain with the metallic plates 1 equal for example , B/b= 10/1.

EFFECT: increases reliability characteristics of a sensor-moisture meter and provides possibility of using it in a grain flow and also increases accuracy of measuring humidity in a grain flow.

1 cl, 6 dwg

FIELD: measuring technique.

SUBSTANCE: method comprises heating the heat-shield structure from one side up to a high temperature, cooling the structure, applying marker dots on the section of the outer surface under study, cutting the axisymmetric specimens of the heat-shield structure, applying marker dots on the side of the specimen at a given distance from the inner surface, cutting the specimen over the planes perpendicular to its longitudinal axis and passing through the marker dots into pieces, subsequent heating of the pieces in the atmosphere of an inert gas, recording the change of weight of the pieces, recording the temperature of the beginning of the decrease of weight of each piece, and judging on the spatial temperature distribution from data obtained.

EFFECT: expanded functional capabilities.

5 dwg