JPS592854B2 - Method and device for measuring temperature and water vapor pressure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method and apparatus for measuring the average temperature of 30 degrees Celsius and the average water vapor pressure of a substance over a certain period of time.

The substance whose temperature is to be measured may be solid, liquid, or gas, such as soil, water, seawater, or air. The invention can also measure water vapor pressure. Conventionally, when measuring the temperature of soil, etc. over a certain period of time, the temperature was recorded almost regularly during that period and the arithmetic mean of the recorded temperatures was taken.

Temperature recording was done by direct reading from a thermometer or thermocouple placed within the material. However, the accuracy of the calculated average value was highly dependent on the number of temperature recordings, the range and frequency of natural variations in temperature, and errors due to the equipment or reading method used. Since the equipment used was generally installed in the open air, there was a great deal of damage caused by animals.
Furthermore, since the temperature must be read and recorded many times, the labor and management costs are high, and the total cost of temperature measurement is enormous. Furthermore, the equipment was often located in remote locations, which added to labor costs and made regular reading and recording difficult. This invention attempts to solve and improve the problems of the conventional technology as described above, and it is possible to measure the average temperature and water vapor pressure of a substance over a certain period of time without frequently measuring the average temperature and water vapor pressure within that period. The object of the present invention is to provide a method and apparatus for centrally measuring and determining substances while minimizing various disturbances to substances, and at great expense.

The basic temperature measurement method used in this invention is to weigh a specific hollow spherical cell filled with desiccant, place it in an airtight or liquidtight container filled with water, and then remove the cell after a certain period of time has elapsed. The weight increase is calculated, and the calculated weight increase is compared with a reference value (described later) to measure the average temperature of the substance over a certain period of time. The above reference value is set as follows. First, add the same weight of dry desiccant to n pieces (where n is 30. The same applies hereinafter).
) of identical spherical cells Xl. X2,・・・・・・・・・
...Place Xn in n airtight and liquidtight containers filled with water,
This container is heated to n different temperatures for a standard period of time, respectively.
For example, hold it for one year. After the reference period has elapsed, the n cells are removed from the container and the outer surface of each cell is thoroughly dried. Therefore, the weight increase of each cell was calculated, and each W
l. w2......Represented as Wn.
This weight increase and each temperature Tl. T2,・
・・・・・・・・・・Represent in a graph in correspondence with Tn, (W1, T1), (W2, T2)...
... A smooth curve obtained by connecting each point of (Wn, Tn) is a curve representing the reference value. The apparatus used to carry out this method of temperature measurement consists of an airtight, liquid-tight container filled with water and containing a hollow spherical cell, the cell having a constant wall thickness and containing water vapor. It is made of a material that allows water to pass through, and contains a dry granular desiccant agent inside.

The container used as the device is preferably a glass container with a screw-on lid and sealed to prevent air or liquid from entering or exiting.

The dimensions of the container are not particularly important, but it goes without saying that the opening must be large enough to allow the spherical cells to be taken in and taken out. A typical shape is about 5 CTL in height, about 3.5 CTr in diameter, and about 2-3 m77 in wall thickness! Just consider the cylinder. The dimensions of the hollow spherical cell containing the desiccant are preferably about 15 to 50 mm in diameter and about 0.25 to 5 mm in wall thickness, particularly preferably about 27 mm in diameter and 1.0 mm in wall thickness.

As mentioned above, the wall thickness of each cell must be constant,
The material must be permeable to water vapor. Particularly desirable cell materials are:
It is a thermoplastic material that not only allows water vapor to pass through, but also has very high impact strength, low water absorption, and is easy to weld.

For example, General Electric Company uses the Lexan 14
A polycarbonate commercially available under the name 1Rclear (Lexanl4lRclear) is suitable. This material has a specific gravity of approximately 1.2, a Rockwell hardness of M78, and a water absorption rate of 24.
It is approximately 1.5% in time (ASTM standard). For a general explanation of the production and properties of polycarbonate, please refer to ``Polycarbonate'' (1962 edition), co-authored by William S. Christopher and Daniel D. Fox, published by Lehnbold Publishing Co., New York. Note that epoxy resin can also be used. However, nylon and the like are hygroscopic, and other materials are undesirable as they can cause deterioration, such as peeling off in layers, even after a year in cold water. The cell may be manufactured by a known method.

Here, we will briefly explain the case where cells are made of polycarbonate. A. Facility··········
...Use an injection mold with three lumens whose inner surfaces are sufficiently hardened and polished for injection molding the upper and lower halves of the cell and the sealing plug.

B. Manufacturing method: The upper half, lower half, and plug are molded, and the upper and lower halves are welded using a solvent.

The spherical cells thus created are filled with desiccant and plugged. The solvent used for welding is dichloromethane. The dimensional tolerance of a cell with a diameter of 27cm and a wall thickness of 1mm is ±0.0 in diameter.
5 mm 1 wall thickness ±0.01 mu. As a desiccant,
Activated zeolite 4A called Molecule Sieve is good. Union Carbide Corporation for this zeolite 4A and other suitable zeolites.
[Union Carbide for Selective Adsorption] published by B1, D1, H Laboratory, Chemicals Division,
("Union Carbide" is a registered trademark of Union Carbide Corporation.) Cells containing dry desiccant should be used when not in use. You can surround it with granular desiccant and store it in an airtight or liquidtight container.

When using this cell, remove it from the container along with the surrounding desiccant, accurately weigh the cell containing the desiccant, and then place it in a container filled with water and seal it.

Now, if you want to measure the temperature of, say, 1 meter underground in a certain piece of land for a year, you can put the device 1 meter underground, take it out after one year, open the container, and drain the water from the container. Remove the cells from the container.

Wipe the cell thoroughly with a soft cloth, and then weigh it accurately. If it is difficult to weigh the cells on-site, dry the inside of the container, put the cells back into the container together with the desiccant, select a suitable location, and weigh the cells as soon as possible. By comparing the calculated weight increase with the reference value (described above), the temperature course of the soil over the year can be directly read from the graph as a single value. Applications of this invention include estimating the age of obsidian hydration, and measuring the temperature of soil at various depths underground in the fields of agriculture and horticulture, and the effects of temperature changes on the growth rate of plants and crops. This includes investigating the

This invention also relates to water vapor pressure (hereinafter also simply referred to as vapor pressure).

) can also be used to measure When measuring the vapor pressure of a certain substance according to the present invention, a hollow spherical homogeneous cell with a constant wall thickness containing a dry desiccant is not placed in a container after its weight is measured, but the above-mentioned method according to the present invention is used. The temperature measuring device, ie a gas-tight, liquid-tight container containing a spherical cell filled with water and containing a desiccant agent, is placed close to each other in the substance whose vapor pressure is to be measured. Depending on the nature of the material, it may be necessary to protect the cell (or even the device) with a cover (eg, a wire mesh box) made of a material that is permeable to fluids. After a predetermined period of time, the temperature of the substance is first measured in the manner described above. Next, the increase in weight of the cell used without being placed in a container is measured, and the vapor pressure is calculated by comparing this with a reference value for vapor pressure (described later). In order to set this reference value of vapor pressure, it is necessary to operate n (n x 30) identical cells at a constant temperature T for one year at n different vapor pressures P1, P2...
After maintaining the temperature at Pn, the weight increase of each cell is measured using the method described above, and each vapor pressure P1, P2,...
......Weight increase W'1, W'2 relative to Pn
,......Display W′n on the graph,
(W'1, P1), (W'2, P2), ...
...Connect each point of (W'N.Pn) to draw a smooth curve.

Next, the reference value of vapor pressure at each temperature is set using the same procedure while varying the temperature T. In this way, after a predetermined period has elapsed, the weight of the cells that have not been placed in a sealed container is measured, the weight increase within that period is calculated, and this is determined at the same time as the standard value of vapor pressure that correlates to the average temperature of the measured substance. By comparing it to the curve, it is possible to determine the average vapor pressure of the substance over that period. In the above explanation, the standard period for setting the standard values for temperature and vapor pressure is one year, but this period can be changed to various lengths such as one month, six months, two years, etc. as necessary. It can be done.

Furthermore, in the above explanation, the cells are spherical only because the spherical shape maximizes the ratio of volume to surface area. Of course, it is possible to employ cells of However, measurements made using spherical cells are the most reliable. Moreover, the spherical shape is easy to manufacture. Note that this invention is particularly effective when measuring the average temperature and water vapor pressure of a substance over a long period of time in a place that is difficult to approach.

Claims (1)

[Claims] 1. The weight of each of two sealed cells each having a wall of a certain thickness made of a material that allows water vapor to pass therethrough and containing a dry desiccant inside is measured, and the first sealed cell is The cell is placed in an airtight or liquid-tight container filled with water, the container is sealed, and the sealed container and the exposed second sealed cell are brought close to each other to measure the temperature and water vapor pressure of the substance in the substance. After a predetermined period of time, the sealed container and second sealed cell are removed from the substance, the first sealed cell is removed from the sealed container, and the outer surfaces of the first and second sealed cells are thoroughly cleaned. After drying, measure the weight of each sealed cell and compare it with the initially measured weight of each sealed cell to calculate the weight increase of each of the first and second sealed cells, and then calculate the weight increase of the first sealed cell. corresponds to each temperature measured in a large number of sealed cells of the same type that have been sealed and installed in containers of the same type as the above for a period of the same length as the above period under various constant known temperatures. Compared with the reference value of weight increase, the first
The average temperature of the substance to be measured is calculated by determining the temperature corresponding to the increase in weight of the sealed cell, and the increase in weight of the second sealed cell is determined in advance by changing the water vapor pressure at various constant known temperatures. The first sealed cell is compared with a reference value of weight increase measured for a number of the same type of sealed cells, each of which has been left exposed for the same length of time as the aforementioned period under a known pressure condition. By determining the water vapor pressure corresponding to the weight increase of the second sealed cell at the same temperature as the average temperature of the substance calculated from the weight increase of A method for measuring temperature and water vapor pressure, characterized by calculating vapor pressure. 2. Two hollow spherical sealed cells each having a wall of a certain thickness made of a material that allows water vapor to pass therethrough and containing a dry granular desiccant inside, and a first sealed cell with water surrounding it. the substance whose temperature and water vapor pressure are to be measured, with the sealed container and the other, second sealed cell remaining exposed, in close proximity to each other; Temperature and water vapor pressure measuring device located in the substance for a predetermined period of time and used to determine the average temperature and average water vapor pressure of the substance.