JPS5818618B2 - Temperature measurement method and device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method and apparatus for measuring the average temperature of a substance over a period of time.

The substance whose temperature is to be measured may be solid, liquid, or gas, such as soil, water, seawater, or air.

Conventionally, when measuring the temperature of soil or the like over a certain period of time, the temperature was recorded more or less regularly during that period, and the arithmetic mean of the recorded temperatures was taken.

Temperature recording was made directly 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 lot 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 installed in remote locations, which increased labor costs and made regular reading and recording difficult.

This invention attempts to improve the conventional technology by solving the problems described above, and it is possible to measure the average temperature of a substance during a certain period of time without frequently measuring it. The purpose of the present invention is to provide a method and apparatus for performing intensive measurements and determinations while minimizing disturbances and without incurring large costs.

The temperature measurement method according to the present invention involves weighing a specific hollow spherical cell filled with a desiccant, placing it in an airtight or liquid-tight container filled with water, and after a certain period of time, taking out the cell and weighing it. 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, put n pieces of dry desiccant of the same weight (however, n
430.

same as below. ) identical spherical cells X1, X2 H...
...Xo is placed in n air-tight, liquid-tight containers containing water, and each of these containers is maintained at n different temperatures for a standard period of time, for example, 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 w12w
2...Represented as wn.

And this weight increase and each temperature T, l T2.
・・・・・・Represent it in a graph in correspondence with To, and VV
F t T 1 r W2 r , r2. ,,,,,w
A smooth curve obtained by connecting each point of n'Tn is a curve representing the reference value.

Apparatus used to carry out the method of this invention.

consists of an air-tight, liquid-tight container filled with water and containing hollow spherical cells, which have a certain wall thickness and are made of a material that is permeable to water vapor. , and contains dry granular desiccant.

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 crfL in height and about 3.5 crf in diameter.
A cylinder with a diameter of 5 cm and a wall thickness of 2 to 3 mm may be considered.

The dimensions of the hollow spherical cell containing the desiccant are approximately 15 to 15 mm in diameter.
501 m, wall thickness 0.25-5 m7IL1 Particularly desirable is one with a diameter of about 1 mm and a wall thickness of 1.0 mm.

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 thermoplastic materials that are not only permeable to water vapor but also have very high impact strength, low water absorption, and are easily welded.

For example, General Electric Co.
1R clear (Le-xan 141 Rclear)
Polycarbonate commercially available under the name .

This material has a specific gravity of approximately 1.2 and a Rockwell hardness of m
78, water absorption rate is approximately 15% in 24 hours (ASTM standard).

A general explanation of the production and properties of polycarbonate can be found in ``Polycarbonate'' (1962) by William Niss, Christopher, Daniel W. Fox, published by Rainbolt Publishing Company, New York.
Please refer to the 2017 edition).

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. Equipment: An injection mold with three internal cavities whose inner surfaces are sufficiently hardened and polished is used 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 27 mm and a wall thickness of 1 m7rL is ±0.05 mm in diameter and ±0.01 mm in wall thickness.

A good desiccant is activated zeolite 4A called molecular sieve.

This zeolite 4A and other suitable zeolites are described in "Union Carbide Molecular Sheep for Selective Adsorption", 3rd edition, 2nd edition, published by Union Carbide Corporation, B.D.H. Laboratory Chemicals Division. (Revised Edition) ("Union Carbide" is a registered trademark of Union Carbide Corporation.

). When the cell containing the dried desiccant is not in use, it can be surrounded by granular desiccant and placed in an airtight or liquid-tight container.

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

If you want to measure the temperature of a piece of land, for example, 1 meter underground, for a year, put the device 1 meter underground, take it out after one year, open the container, drain the water from the container, and remove the cell from the container. Take out.

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 together with the desiccant back into the container, transport them to an appropriate 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 at various depths underground in the fields of agriculture and horticulture to determine the effect of temperature changes on the growth rate of plants and crops. This includes investigating the

In addition, in the above explanation, the standard period for setting the temperature standard value was one year, but this period can be set to various lengths such as one month, six months, two years, etc. as necessary. I can do it.

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 the present invention is also effective in measuring the average temperature of seawater at various depths over a long period of time.

Claims (1)

[Claims] 1. The weight of a sealed cell, which has walls of a certain thickness made of a material that allows water vapor to pass therethrough and contains a dry desiccant inside, is measured, and the sealed cell is filled with water and airtight. , put it in a liquid-tight container, seal the container, place this sealed container in the substance whose temperature is to be measured for a predetermined period of time, take out this sealed container from the substance after the elapse of a predetermined period, and open the sealed cell. After removing the cell from the container and thoroughly drying its outer surface, measure its weight.Compare it with the initially measured weight to calculate the weight increase of the sealed cell. a period of the same length as said period under
Determining the temperature corresponding to the weight increase by comparing with a reference value of the weight increase corresponding to each temperature measured for a large number of sealed cells of the same type each installed in a container of the same type as above. A temperature measuring method characterized by calculating the average temperature of a substance over a predetermined period of time. 2. A hollow spherical sealed cell with a wall of a certain thickness made of a material that allows water vapor to pass through, and a dry granular desiccant is placed inside the cell, and the sealed cell is filled with water around it and sealed. A temperature measuring device consisting of an air-tight, liquid-tight container, in which the sealed container is placed in a substance whose temperature is to be measured for a predetermined period of time, and is used to calculate the average temperature of the substance.