(57) Abstract:The proposed condensation hygrometer relates to techniques for measuring the humidity of gases and can be used for measuring low dew point directly at high pressures. The measuring chamber of the hygrometer made in the form of multiple longitudinal symmetrical cylindrical channels, which is the condensing mirrors. One of the channels is equipped with an insert in the form of a hollow cylinder made of a material with lower thermal conductivity than the material of the measuring chamber. The cavity insert is connected with the output of the sample gas pipeline and manifold. The hygrometer is equipped with a cooler, a temperature sensor, a light source and a photodetector. Between the light source and the measuring chamber installed reflector. A sight glass is located coaxially with the measuring chamber. The technical result of the invention is to improve the measurement accuracy of the dew point and the reduction of the sample gas. 2 Il. The invention relates to techniques for measuring the humidity of gases. Primary area of use is the measurement of low values of dew point directly at high pressures.The disadvantage of this hygrometer is that a relatively large volume of the measuring chamber and a relatively small area of the condensing mirror lead to the fact that the great mass of the sample gas does not participate in the process of condensation flowing almost in the boundary layer, which leads to an increase in its consumption when measuring dew point. In addition, the temperature difference between the analyzed gas and condensing mirror increases with the lowering of temperature of the condensing mirror that leads to increased measurement errors.Known condensation hygrometer containing the measuring chamber to the condensing mirror in the form of a cylindrical channel, the cooler, the light source, the photodetector and the temperature sensor (see, for example, ).This hygrometer increased area of the condensing mirror. However, as the hygrometer discussed above, a large mass of the sample gas does not participate in the process of condensation of water vapor, and also has a substantial temperature difference between the analyzed gas and condensing mirror that is not rnost which is a measuring mirror, cooler, the light source, the photodetector and the temperature sensor (see, for example ) adopted for the prototype.In the prototype reduced the number of analyzed gas not participating in the process of vapor condensation, but not resolved the issue of reducing the temperature difference between the analyzed gas and condensing mirror, resulting in large measurement errors.In addition, all considered hygrometers excluded the possibility of visual observation of the surface of the condensing mirror.The result of the invention is to improve the measurement accuracy of the dew point and reducing the number of analyzed gas needed for the measurements.This result is achieved by the fact that in the proposed condensation hygrometer containing the measuring chamber to the condensing mirror in the form of a cylindrical channel, the cooler, the light source, the photodetector and the temperature sensor, the measuring chamber in the form of several longitudinal symmetrical channels, one of which is equipped with an insert in the form of a hollow cylinder made of a material with lower thermal conductivity than the material of the measuring chamber, the cavity of which is connected to the input of made reflector, and coaxially with the measuring tube is a sight glass.The invention and its distinguishing features are that in the alleged condensation hygrometer measuring chamber in the form of several longitudinal symmetrical channels, one of which is equipped with an insert in the form of a hollow cylinder made of a material with lower thermal conductivity than the material of the measuring chamber. Between the light source and the measuring chamber installed reflector and coaxially with the measuring tube is a sight glass.This results in a positive effect, consisting in the following. Rays from the light source, Bouncing, fall on all parts of the measuring mirrors, with a direct hit of light beams on the photodetector excluded. The presence of inserts of a material with lower thermal conductivity connecting the inlet pipe and header, allows you to pre-cool the gas, thereby decreasing the temperature difference between the analyzed gas and the surfaces of the channels of the measuring chamber.Compared with the prototype of these channels (measuring mirrors) can be performed with much smaller diameters, as a result is that you can greatly reduce its consumption. In addition, the design provides for visual observation of the degree of purity of channels condensing mirrors to reveal the need of cleaning them. Compared with the prototype of the proposed condensation hygrometer relatively simple design.Variant of practical implementation of the proposed condensation hygrometer shown in Fig. 1 and 2, which respectively depict the hygrometer in the cut and its cross section along a - A.Condensation hygrometer includes measuring chamber 1, cases 2 and 3, the light source 4, a reflector 5, a protective glass 6 and 7, a sight glass 8, the inlet 9 and outlet 10 pipelines, box 11, collective screen 12, a sensor 13, the manifold 14, the insulating strips 15 and 16, the temperature sensor 17, the cooler 18.The measuring chamber 1 is made of metal with high thermal conductivity (such as copper) with polished surfaces of the channels, the insert 11 and the inlet pipe 9 made of a metal with a relatively low thermal conductivity (e.g., stainless steel), the reflector 5 is made of metal (e.g. stainless steel) with a polished surface, for the manufacture of teplota is the quality of the light source 4 can be a source of infrared radiation, collectively, the screen 12 is a metal cone with a polished inner surface, the hole is set to the photodetector 13 (for example, photodiode), the cooler 18 is, for example, a thermopile, and a temperature sensor 17 is a thermistor.Condensation hygrometer works as follows.Analyzed the high-pressure gas through the inlet pipe 9 connected tangentially (not shown) with the cavity of the insert 11, enters the collector 14, where uniformly passes through the longitudinal channels of the measuring chamber 1, and then flows into the cavity between the protective glass 6 and through an outlet pipe 10 is discharged into the atmosphere. Simultaneously the cooler 18, the light source 4, the photodiode 13 and the temperature sensor 17. Due to significant differences of coefficients of thermal conductivity of the material of the measuring chamber 1 and the insert 11, will take place a certain temperature difference, automatically supported in the process. The temperature of the insert 11 is not reduced until the temperature of the gas dew point. The light rays from the light source 4 enters the reflector 5 and is directed in the longitudinal channels of the measuring chamber 1 through stvie providing coverage of all surfaces of the channels, to reduce measurement error. In Fig. 1 shows the course of the rays from the light source 4 to the photodetector 13 in one of the channels.In addition, the use of an infrared light source, the rays of which intensively absorbed by the condensed phase of water vapor, also reduces the measurement error. In the absence of the condensed phase on the inner surfaces of the channels of the measuring chamber 1, the signal on the photodetector 13 is maximum. During the formation of the condensed phase the intensity of the light rays falling on the photodetector 13, sharply decreases due to the absorption of light condensed phase. Defined in this moment the temperature of the measuring chamber 1 temperature sensor 17 is the dew point of the gas.Visual monitoring of the condition of the surfaces of the channels is carried out through a sight glass 8 to reveal the need of cleaning them.Thus, the proposed condensation hygrometer compared with the prototype allows to reduce the amount of the sample gas, to automatically maintain the temperature difference between the analyzed gas and measuring channels, and substantially lowered the 397830, CL G 01 N 25/66, 1973.2. Auth.St. USSR N 488126, CL G 01 N 25/66, 1975.3. Auth.St. USSR N 1681218, CL G 01 N 25/66, 1991. Condensation hygrometer containing a measuring chamber with a condensing mirror, the cooler, the light source, the photodetector and the temperature sensor, wherein the measuring chamber in the form of several longitudinal symmetrical cylindrical channels, one of which is provided with an insert in the form of a hollow cylinder made of a material with lower thermal conductivity than the material of the measuring chamber, the cavity of which is connected to the input of the sample gas pipeline and collector, and the rest are channels condensing mirrors, between the light source and the measuring chamber installed reflector and coaxially with the measuring tube is a sight glass.
FIELD: measurement technology.
SUBSTANCE: working body of indicator is made in form of thin metal membrane which is subject to cooling according to linear law by means of thermo-electric cooler. Direct measurement of temperatures of body and cooler is provided. At the moment of water vapor condensation the speed of cooling of membrane reduces abruptly due to consumption of cold used for cooling of moisture that condenses on surface of membrane turned to atmosphere.
EFFECT: improved precision of indication.
FIELD: measurement technology.
SUBSTANCE: device has two units. The first one combines mechanical units and has casing, connection tube with gas duct. The tube branches into the main one and internal one placed inside, electrically connected to each other. Filter collecting moisture is mounted on entry to the internal tube. The third tube having entry closed from the gas flow side is formed above the internal tube surface. The fourth tube is located in the third tube. The fourth and the third tube go out from the main one. The fourth one is connected to pump which outlet is separately connected to cooler and heater. Dielectric layers cover external surface of the third tube and internal surface of the fourth one. Its dielectric properties depend on moisture amount. The dielectric layers are covered with reticular electrodes bearing temperature gages attached to them. The second unit is electric circuit for shaping, processing and recording electric signal. It has generator, bridge circuit, differential amplifier, recorder and two-channeled amplifier.
EFFECT: high accuracy in concurrently measuring humidity and temperature.
FIELD: measuring technique.
SUBSTANCE: hygrometer comprises measurement chamber with sight and protecting glasses, pipelines for gas to be analyzed and cooling gas, cool conductor with condensation surface and temperature gage, base, throttle, and control members. The throttle may be mounted in the bottom section of the cool conductor with condensation surface or in the base.
EFFECT: enhanced accuracy of measurement.
2 cl, 2 dwg
FIELD: measurement engineering.
SUBSTANCE: controlled gas is subject to cool down due to passing it through layer of liquid, temperature of which liquid is kept equal to preset value of "dew point temperature for higher hydrocarbons". Correspondence of gas quality according to "of "dew point temperature for higher hydrocarbons" is determined by absence or presence of higher hydrocarbon film on surface of liquid. For the case, the liquid is chosen with density being higher than density of liquid state of hydrocarbons and in which liquid the liquid higher hydrocarbons do not solve. Water, diethylene glycol and methanol should solve in the liquid, which matter normally are present in controlled gas. Calcium chloride water solution of required concentration can be used as the liquid.
EFFECT: improved truth of quality control.
1 dwg, 1 tbl
FIELD: measuring technique.
SUBSTANCE: method comprises step cooling of solid body, maintaining a constant temperature at each step for a time period, and step cooling down to a temperature of onset condensation. The condensation temperature is determined from the formula proposed.
EFFECT: enhanced accuracy of measurements.
2 cl, 3 dwg
FIELD: measurement technique.
SUBSTANCE: humidity of natural gas is measured by means of dewpoint hygrometers. According to method, hydrate formation onto mirror is prevented due to introduction of vapors of fluid to gas coming for analysis into dewpoint hydrometer. Freezing point of fluid is lower than -80°C and tangent of angle of loss is small at measurement of dew point temperature by means of SHF/EHF hygrometer. Amount of vapor is measured from reduction in temperature of hydrate-formation at 8-10°C in relation to overload capacity of dew point temperature for tested gas. Methyl, ethyl, propyl alcohols or acetone are taken as fluid.
EFFECT: reduced systematic error; prevention of hydrate formation.
2 cl, 3 dwg
SUBSTANCE: invention concerns gas humidity measuring techniques. Hygrometer contains casing, coaxial source and receiver of light beams between which there is mounted flat optically transparent condensation mirror, temperature sensor and cooler unit. One version of hygrometer implies that condensation mirror is provided with not less than two through channels perpendicular to axis of source and receiver of light beams which lateral surfaces are parallel to condensation mirror planes. The second version of hygrometer implies that casing is provided with internal grooves, and condensation mirror with at least one through channel, and lateral surfaces of through channels being parallel to condensation mirror planes.
EFFECT: increased accuracy of measurements.
2 cl, 4 dwg
FIELD: physics; measurement.
SUBSTANCE: invention relates to measurement techniques and more specifically to measurement of humidity of gases particularly natural gas, containing a high level of technical trace constituents - compressor oil, vapours of desiccant alcohols (glycols), and higher hydrocarbons. Gas is passed over the cooling surface of a metallic mirror and the dew point temperature (DPT) is recorded. At operating pressure the gas is fed into an enclosed volume. Using the mirror, the entire gas is cooled to a temperature invariably lower than the dew point. Thermohygrometric equilibrium is established between the falling condensate and the surrounding gas and mass of the water precipitated on the mirror is measured. The absolute moisture content, adjusted to normal conditions, is found, corresponding to saturated gas at temperature of the mirror, using known tables or graphs which link humidity of gas with dew point temperature at operating pressure. The complete normalised humidity of the initial natural gas is calculated using a given mathematical relationship, and then using the same tables or graphs, the dew point temperature is found.
EFFECT: reduced errors.
FIELD: measurement equipment.
SUBSTANCE: invention refers to relative humidity sensors. In the device, metal chrome-plated mirror plate is provided with a number of conical vertical holes and conical metal movable electrodes with micrometric thread placed in them. Control of interelectrode gap is provided by movement of electrodes along axis of conical vertical holes. Moisture microparticles allow closing circuit of electrode with plate, which allows measuring dew point temperature.
EFFECT: providing sufficient accuracy in actual operating conditions.
FIELD: instrument making.
SUBSTANCE: low-temperature humidity metre includes light generator for formation of light flux, and two mirrors. At that, one mirror is equipped with cooling system with thermometre to cool its surface when dew point value is being determined. Temperature of the other mirror is kept stable and equal to the temperature of layers enveloping its atmospheres. As light generator there used is semiconductor laser or laser diode, or light-emitting diode, or luminescent diode generating light flux. On the way of light generator there located is plane convex lens. Light flux after the lens interacts with divider so that it can be split into two beams of equal intensity. Beams are directed through plane convex and rod lenses to the appropriate mirrors. On the way of light fluxes reflected from surface of mirrors there installed in series are plane convex lenses and photodetectors. The latter generate the signals proportional to intensity of light fluxes. Outputs of the above photodetectors are connected to the appropriate two inputs of information processing unit. The third input of information processing unit is connected to the output of semi-conductor thermometre. Outputs of the above unit are connected to information board and to cooling system. At that, light flux on its way from light generator to photodetectors is enclosed in light guides.
EFFECT: enlarging the range of working temperatures, improving measurement accuracy.
7 cl, 1 dwg