RU2658552C1 - Device for measuring the vertical profile of environment temperature - Google Patents

Abstract

FIELD: measuring equipment.

SUBSTANCE: invention relates to thermometry and can be used in meteorology to investigate the vertical distribution of ground or soil temperature. Device contains a probe in the form of a vertical chain of digital temperature sensors having a 1-WIRE communication protocol, interconnected in parallel and having unique logical numbers; cable entry through which a cable is output that connects the sensors to a controller-logger for reading information. Device makes it possible to significantly reduce the distortion of temperature distribution by heat flows through the communication cable due to the fact that the cable entry is located at a distance of at least 200 mm from ground or soil surface, while the horizontal part of the cable going from the probe to the controller (logger), horizontally laid in a closed trench, has a length of at least 1 meter.

EFFECT: reduction of the distortion of temperature distribution by heat flows through the communication cable.

1 cl, 1 dwg

Description

The invention relates to measuring technique and can be used to measure the temperature profile of soil, soil, including permafrost soils and soils.

Known thermal probes for measuring the temperature profile of the medium (RU No. 97524, 128323 U1 G01K 3/00). Devices include a thermocut, with temperature sensors placed on it, a connector for connecting a processing device. The braid is enclosed in a rubber tube, both ends of which are sealed, inside which a polyethylene tube is inserted to give rigidity, the upper end of which is left open, and a polyethylene sleeve with a sealed lower end. Measurements are taken in wells obtained by mechanical or thermal drilling.

Disadvantages - devices can be used to measure the temperature of ice, including hummocks and ham.

It is known to use automatic recording devices (loggers) for temperature monitoring of permafrost soils (Cryosphere of the Earth, 2011, vol. XV, No. 1, pp. 23-32). The quality of temperature monitoring of soils and the performance of logger devices for many years of use depends on compliance with certain rules for installing temperature sensors in soils. Ignoring them can lead to the fact that even the most advanced equipment will be useless.

The disadvantage is the use of a cable composed of copper conductors to connect temperature sensors to the logger. The cable is located vertically and is a heat conductor, which leads to a distortion of the temperature distribution.

The closest in technical essence is a temperature probe for measuring the soil temperature profile TP32MTT_03_D http://www.directindustry.com.ru/prod/delta-ohm/product-25140-1572320.html. The device contains temperature sensors fixed in a fiberglass pipe for simultaneous measurement of temperature at 7 levels: +5 cm, 0, -5 cm, -10 cm, -20 cm, -50 cm, -1 m relative to the soil surface (according to the recommendations of the World Meteorological Organization ) In the upper part of the pipe, a cable is output for transmitting data from sensors. Data is transmitted via the RS485 interface using the MODBUS RTU protocol to the logger.

The disadvantage of this device is the probability of introducing distortion of the temperature field along the probe with a data cable.

The objective of the invention: to reduce the temperature disturbance of the probe sensors acting through the cable conductors.

Effect: reduction of temperature distortions in the inventive temperature probe increases the accuracy of the measurement of the vertical temperature profile.

The technical result is achieved by the fact that, as in the known one, the proposed device for measuring the vertical profile of the medium temperature comprises a probe in the form of a vertical chain of digital temperature sensors having a 1-WIRE communication protocol, connected in parallel and having unique logical numbers; cable entry through which a cable is connected connecting the sensors to the controller-logger for reading information.

Unlike the device known in the claimed device, the cable entry connecting the chain of temperature sensors to the controller is fixed at a distance of at least 200 mm from the upper end of the protective casing, which coincides with a zero level of soil or soil, and part of a horizontally laid cable is at least one meter long, counting from the probe, placed in a closed trench.

The use of the claimed probe design with a cable branch location of at least 200 mm from the end of the probe is due to the fact that lines of equal temperature at a vertical section of the soil at this depth become almost horizontal and do not cross the cable laid horizontally. Thus, when the temperature of the soil changes, the cable and the sensor closest to the cable are heated and cooled synchronously. The shorter laying depth of the initial part of the cable will cause several zones with different temperatures to act on the cable, and due to the high thermal conductivity, its temperature will differ from the temperature of the soil around the near sensor. The minimum length of the horizontal part of the cable 1 m is selected empirically, based on the operating experience of thermal probes accumulated by the LGIT laboratory. The shorter length of the horizontal part of the cable can lead to the fact that the heat fluxes from the end of the cable, located at a different depth and having a different temperature, are not completely shunted by the surrounding soil, have time to reach the probe along the cable cores and can distort the distribution of heat in the temperature sensors.

The invention is illustrated in the drawing.

The device comprises a probe 1 in the form of a vertical chain of digital temperature sensors 2 having a communication protocol 1-WIRE, connected together in parallel and having unique logical numbers; cable entry 3, through which a cable 4 connects the sensors to the controller-logger (not shown) for reading information. The cable outlet 3 is located at a distance of not less than 200 mm from the upper end of the probe 1.

The device operates as follows.

Before use, the device must be installed permanently, observing the following requirements:

The device is located in the well with a depth equal to the length of the probe. The upper end of the probe 1 coincides with a zero level of soil or soil. Near the well there is a trench with a depth of at least 200 mm (per bayonet shovel) and a length of at least 1 m. The beginning of the trench coincides with the upper end of the well. The end of the trench leads to the location of the logger (not shown). Cable 4 is located at the bottom of the trench.

Temperature sensors 2 installed on probe 1 simultaneously measure the temperature of the medium at 7 levels: +5 cm, 0, -5 cm, -10 cm, -20 cm, -50 cm, -1 m relative to the soil surface (according to the recommendations of the World Meteorological Organization). The controller-logger reads the data of sensors 2 according to the 1-WIRE protocol through cable 4, passing through cable entry 3, and fixes them in the internal memory.

Information sources

1. RU 97524 U1 G01K 3/00

2. RU 128323 U1 G01K 3/00

3. P.Ya. Konstantinov, A.N. Fedorov, T. Machimura, G. Ivahan, X. Yabuki, J. Yijima, F. Kostar. “The use of automatic recording devices (loggers) for temperature monitoring of permafrost soils”, Earth Cryosphere, 2011, vol. XV, No. 1, p. 23-32.

4. Probe for measuring the soil temperature profile TP32MTT_03_D http://www.directindustry.com.ru/prod/delta-ohm/product-25140-1572320.html

Claims (1)

A device for measuring the vertical profile of the temperature of a medium containing a probe in the form of a vertical chain of digital temperature sensors having a 1-WIRE communication protocol, connected together in parallel and having unique logical numbers; cable entry through which a cable is connected connecting the sensors to the controller-logger for reading information, characterized in that the cable entry connecting the chain of temperature sensors to the controller is located at a distance of at least 200 mm from the upper end of the protective housing, which coincides with a zero soil level or soil, and part of a horizontally laid cable with a length of at least one meter, counting from the probe, is placed in a closed trench.

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