JP4775710B2 - Thermocouple thermometer - Google Patents

Description

  The present invention relates to a thermocouple thermometer with improved reference junction compensation accuracy of a terminal board.

  Prior art documents related to thermocouple thermometers include the following.

JP-A-6-201485

FIG. 6 is an explanatory diagram of a configuration of a conventional example that is generally used conventionally, FIG. 7 is an explanatory diagram of a main part of FIG. 6, (a) is a front view, and (b) is a side view.
In FIG. 6, a thermocouple 1 is a sensor that measures a relative temperature.
In order to know the absolute temperature of the measurement contact (measurement target point) 2 with the thermocouple 1, it is necessary to measure the temperature of the reference contact 3.
For example, there is a method of measuring the temperature of the terminal 5 of the measuring instrument 4.

As shown in FIG. 7, a terminal board 12 and a reference contact compensation printed board assembly 13 are provided on a base printed board 11 of the terminal board.
Although not shown in the drawing, the reference junction compensation printed board assembly 13 may include a sensor peripheral circuit in addition to the reference junction compensation sensor.
The connector 14 is a connector for connecting the terminal board assembly to the measuring instrument main body.

  FIG. 8 is a diagram illustrating the configuration of another conventional example that is generally used conventionally. FIG. 8A is a front view, FIG. 8B is a side view, FIG. 9A is an operation diagram of FIG. ) Shows the temperature distribution of the measurement terminal 23 and the reference junction compensation sensor 22.

  In the conventional temperature measurement using a thermocouple, the voltage of the temperature measuring contact of the wiring terminal portion 21 of the thermocouple is measured, and at the same time, the temperature of the reference contact of the wiring terminal portion 21 of the thermocouple is changed to another reference contact compensation sensor 22. Measure with.

Then, the temperature difference of the temperature measuring junction is measured by calculating the potential difference with the temperature measuring junction and performing correction (linearization) according to the thermoelectromotive force according to the thermocouple type.
In the temperature measurement input unit of FIG. 8, the reference junction compensation sensor 22 is arranged so as to have the same temperature as the terminal temperature (1-6CH).

Since the temperature difference between the measurement input terminal 23 and the reference junction compensation sensor 22 becomes an error when measuring the temperature with a thermocouple, the temperature difference between the multipoint measurement input terminals 23 is reduced according to the product, The arrangement of the reference junction compensation sensor 22 is determined so as to be equal to the terminal temperature.
Reference numeral 24 denotes a terminal cover, and 25 denotes a housing.

Such an apparatus has the following problems.
First, problems in the conventional example of FIG. 7 will be described.
◇ About temperature gradient in terminal board In many cases, there are multiple measurement channels in measuring instruments. For example, in FIG. 7, the terminal plate assembly of a 10-channel measuring instrument is illustrated.

  Here, there is a gradient in temperature between terminals 1ch to 10ch. In order to keep the error of the reference junction compensation system within a target range, it is necessary to find a point in the terminal board assembly space where a representative value (for example, an average value) of the temperature distribution between terminals can be sampled.

For example, in a situation where the temperature of 1ch is the highest and 5ch is the average temperature, and the temperature of 10ch is the lowest, if the reference junction compensation sensor is laid out in the vicinity of 10ch, the measurement value of 1ch is not within the reference. Therefore, it is important to find a place where representative values can be sampled.
However, there are various arrangements of parts in the measuring instrument. Therefore, the positions of the heat generating parts are also various, and it takes a very long time to find a place where the representative value can be sampled.

◇ Fig. 7 Tuning with the conventional configuration.
The temperature measurement value of the printed board assembly 13 for reference junction compensation is calibrated in advance so as to show an accurate value.
The printed board assembly 13 for reference contact compensation is connected to the base printed board 11 of the terminal board assembly by a connector or the like.

  In order to be able to measure the same temperature as the representative temperature of the terminal block 12, the position of the reference contact compensation sensor in the printed circuit board assembly 13 for reference contact compensation, the position of the printed circuit board assembly 13 for reference contact compensation, and other mechanical Adjust the structure.

As above,
There are many mechanical constraints on the layout location of the printed circuit board assembly 13 for reference contact compensation.
◇ Many development steps are required to tune the reference junction compensation system.
◇ It is difficult to thermally couple the printed circuit board assembly 13 and the terminal block 12 for reference junction compensation.
◇ It is difficult to design a high-precision reference junction compensation system.
◇ If the terminal board assembly is exposed to a rapid temperature change, the follow-up is slow.

Hereinafter, each problem will be described in detail.
◇ Difficulty in layout and tuning.
The printed circuit board assembly 13 for reference contact compensation is relatively large compared to a narrow space where the entire terminal board assembly is allowed, and is not large enough to be placed anywhere in the terminal board assembly, but is a size that hinders placement. .

When the printed board assembly 13 is connected to the terminal board assembly by a connector, the mounting shape is almost determined by the restriction of the connector shape. Normally, it is attached at right angles to the terminal board surface.
The printed board assembly 13 is not flexible.
There are significant restrictions when determining the layout in the terminal board assembly.

  For example, in FIG. 7, although the back surface of the connector 14 has a space, the printed circuit board assembly 13 for reference contact compensation cannot actually be laid out. The reason is that the connector of the printed board assembly 13 for compensating the reference contact cannot be provided on the back side of the connector 14.

  Also, for example, even if the vicinity of the 5ch + terminal is the optimum place for the layout of the printed circuit board assembly for reference contact compensation in terms of temperature, it is close to the 5ch + terminal due to mechanical restrictions. I can not layout.

  In order to move the position of the printed circuit board assembly 13 for reference contact compensation to the optimum position on the printed circuit board 11 of the terminal board assembly, a plurality of holes for connecting connectors are formed on the printed circuit board 11. Alternatively, it is necessary to recreate the base printed board 11 itself. Therefore, it is difficult to finely adjust the position of the printed board assembly 13 for reference contact compensation.

FIG. 7 shows an example in which the printed circuit board assembly 13 for reference contact compensation is laid out on the upper side (component surface) of the base printed circuit board 11.
However, depending on the product, the printed circuit board assembly 13 for compensating the reference contact may be mounted on the back side of the base printed circuit board 11 (that is, the connector 14 side = solder surface) due to space.

  As a general physical property, the temperature condition should be better near the terminal block 12, but when the printed circuit board assembly 13 for compensating the reference contact is mounted on the back surface, the tuning becomes more difficult and the development period takes longer. Become a trend.

  In short, as described above, there are layout constraints as described above, and it takes a very large number of man-hours to adjust the temperature indicated by the reference junction compensation system to the optimum temperature.

◇ Difficulties in thermal coupling Generally, it is better to physically attach the reference junction compensation sensor close to the terminal, so that thermal coupling is better and a highly accurate reference junction compensation system can be achieved.
However, it is troublesome to make the printed circuit board assembly 13 for reference contact compensation mounted perpendicularly to the base printed board 11 in close contact with the terminal block 12 and is difficult to manufacture.

  Further, when the printed circuit board assembly 13 for compensating the reference contact is mounted on the back side (= solder surface) of the base printed circuit board 11, it is difficult to adhere to the terminal block 12, so that the thermal coupling becomes more difficult.

◇ It is difficult to design a high-precision reference junction compensation system.
One of the important elements of measuring instruments is measurement accuracy. In thermocouple temperature measurement, the measurement accuracy of the reference junction compensation system also affects the temperature measurement accuracy. In order to make a reference junction compensation system with higher accuracy than the present one, it is difficult to use the current reference junction compensation printed board assembly as it is.

◇ When the terminal board assembly is exposed to a rapid temperature change, the measured value follows slowly.
When there is a temperature change in the terminal board, it is ideal that the measured value of the printed board assembly 13 for reference junction compensation follows without delay, but in reality, a delay occurs. In other words, the measurement accuracy of the entire thermocouple measurement system is reduced during a time zone that is not followed.
This is because the thermal coupling between the terminal board and the reference junction compensation is loose.

Next, problems in the conventional example of FIG. 8 will be described.
In the measuring instrument alone, the temperature difference between the measurement terminal and the reference junction becomes an error when measuring the temperature with a thermocouple, so that the temperature difference between the multipoint measurement input terminals 23 is reduced according to the product, The arrangement of the reference junction is determined so as to be equal to the terminal temperature.

  However, depending on the installation environment of a specific actual system, there may be a local heat source A around the measuring instrument as shown in FIG. In this case, temperature distribution occurs at the measurement terminal and the reference junction due to the influence of the heat source A, and the temperature balance between the “terminal temperature of the multi-point input CH section” and the “reference junction” is lost and the temperature measurement error increases.

The object of the present invention is to solve the above problems.
7 is the purpose to solve the problems of the conventional example.
The layout of the reference junction compensation sensor can be easily positioned to shorten the product development period.
Reduce mechanical structural constraints.

Reduce the number of rework with the base printed board 11.
The thermal coupling between the reference junction compensation sensor and the terminal block 12 is improved.
Improve reference junction compensation with high accuracy.
Develop a reference junction compensation system that quickly follows the rapid fluctuation of terminal board temperature.
A configuration that can cope with the downsizing of measuring instruments, which is the current trend.

8 is the purpose to solve the problems of the conventional example.
When there is a local heat source A around the measuring device as shown in FIG. 9 due to incorporation into a specific actual system device, etc., temperature distribution occurs at the measurement terminal and the reference junction due to the influence of the heat source A. The purpose is to correct that the temperature measurement error increases due to the imbalance between the temperature of the terminal temperature of the multi-point input CH section and the temperature of the “reference contact”.

In order to achieve such a problem, in the present invention, in the thermocouple thermometer of claim 1,
In the thermocouple thermometer having the reference contact compensation means of the terminal plate, one end is connected to one end of the terminal plate and the other end is moved along the terminal plate, and the other end of the moving means is provided. A reference contact compensation sensor and a fixing means for fixing the reference contact compensation sensor to the terminal board are provided.

In the thermocouple thermometer according to claim 2 of the present invention, in the thermocouple thermometer according to claim 1,
At least two or more units of the moving means and the reference contact compensation sensor are used.

In the thermocouple thermometer according to claim 3 of the present invention, in the thermocouple thermometer according to claim 1 or 2,
The moving means is a flexible printed board.

In the thermocouple thermometer according to claim 4 of the present invention, in the thermocouple thermometer according to claim 3,
The flexible printed board is provided with an electric circuit component.

In the thermocouple thermometer according to claim 5 of the present invention, in the thermocouple thermometer according to any one of claims 1 to 4,
The fixing means uses an adhesive.

In the thermocouple thermometer according to claim 6 of the present invention, in the thermocouple thermometer according to claim 4,
The pressure-sensitive adhesive is a double-sided tape.

In the thermocouple thermometer according to claim 7 of the present invention, in the thermocouple thermometer according to claim 4,
An adhesive is used as the pressure-sensitive adhesive.

According to the first to seventh aspects of the present invention, the following effects can be obtained.
During development, the position of the reference junction compensation sensor can be freely changed, shortening the tuning period.
Mechanical constraints on the reference junction compensation layout, such as connector position, are greatly reduced.
Even if the reference contact compensation layout position is changed, the design conditions such as the base printed board of the terminal board assembly are not affected so much, so the number of times the printed board is recreated is reduced, resulting in a shorter development period.

Because thermal coupling with the terminal (or terminal block) is better than the current method,
Tuning is easy.
Expected to improve accuracy of reference junction compensation.
It is possible to realize reference junction compensation in which the measured value quickly follows the rapid fluctuation of the terminal board temperature.

Depending on the incorporation of the measuring instrument into the system device, the temperature around the measuring instrument may fluctuate greatly in a relatively short time. This is because in such a case, the reference junction compensation is required so that the measured value can quickly follow the temperature change.
Since a plurality of reference junction compensation sensors can be easily attached, the terminal temperature can be measured with high accuracy.

Hereinafter, the present invention will be described in detail with reference to the drawings.
FIGS. 1A and 1B are explanatory views of a main part configuration of an embodiment of the present invention. FIG. 1A is a front view, FIG. 1B is a side view, and FIG.
In the figure, the same symbol structure as in FIG. 7 represents the same function.
Only the difference from FIG. 7 will be described below.

In FIG. 1, the moving means 31 has one end connected to one end of the terminal plate and the other end moving along the terminal plate.
In this case, the moving means 31 is a flexible printed board.
In this case, an electric circuit component 311 is provided on the flexible printed board 31.

The flexible printed circuit is an abbreviation for Flexible Printed Circuit.
The base material of the flexible printed circuit is an insulator, and an electric circuit is formed on the base material or with a conductor interposed between the base material and the base material.
Reference numeral 312 denotes a connector of the flexible printed board 31 provided at one end of the flexible printed board 31.

The reference contact compensation sensor 32 is provided at the other end of the moving means 31 as shown in FIG.
The fixing means 33 fixes the reference junction compensation sensor 32 to the terminal board.
In this case, the fixing means 33 uses an adhesive.
In this case, the adhesive 33 is a double-sided tape.
Note that the adhesive 33 may be an adhesive.

In the above configuration, the reference contact compensation sensor 32 is mounted on the flexible printed board 31.
Note that the peripheral circuit 311 of the reference contact compensation sensor 32 may be attached on the flexible printed circuit 31 as shown in FIG.

The sensor 32 portion of the reference junction compensation is attached to a place (terminal or terminal block 12) where the temperature is to be measured.
In FIG. 1, a relatively long flexible printed board 31 is bent and attached to the position of 5ch. For example, if the flexible printed board 31 is extended, the temperature at the position of 1 ch (right end ch) can be easily measured.

In attaching the reference contact compensation sensor 32, an adhesive 33 is used. In this case, an adhesive having good thermal conductivity is used. In attaching, the double-sided tape 33 may be used.
In this case, a double-sided tape with good thermal conductivity is used. Usually, the tape is very thin and has better heat conduction than air, so a superior type can be used for temperature evaluation.

In the design stage, the layout location of the reference junction compensation is tuned and positioned as described above.
In the manufacturing stage, a flexible printed circuit assembly on which a reference contact compensation sensor or the like is mounted is attached at a predetermined position.

As a result,
During development, the position of the reference junction compensation sensor 32 can be freely changed, so that the tuning period can be shortened.

Mechanical constraints on the reference junction compensation layout, such as connector 312 position, are greatly reduced.
Even if the reference contact compensation layout position is changed, the design conditions such as the base printed board 11 of the terminal board assembly are not significantly affected, so that the number of times the printed board is remade is reduced, resulting in a shortened development period.

Since thermal coupling with the terminal (or terminal block 12) is better than the current method,
Tuning is easy.
Expected to improve accuracy of reference junction compensation.
It is possible to realize reference junction compensation in which the measured value quickly follows the rapid fluctuation of the terminal board temperature.

  Depending on the incorporation of the measuring instrument into the system device, the temperature around the measuring instrument may fluctuate greatly in a relatively short time. This is because in such a case, the reference junction compensation is required so that the measured value can quickly follow the temperature change.

FIG. 3 is an explanatory view of the main part configuration of another embodiment of the present invention.
When a device that performs temperature measurement using a thermocouple is incorporated in a system device, the temperature measurement may be affected depending on the ambient temperature environment inside the system device.
Usually, in a multi-point temperature measuring device using a thermocouple, the terminal temperature of the multi-point input CH section is measured by a single reference junction compensation sensor provided separately, and the temperature is measured by compensating as the temperature of the measurement terminal section. .

At this time, if the ambient temperature of the measuring device is constant, the temperature of the “multi-point input CH section terminal temperature” and the “reference junction compensation sensor” are kept in balance regardless of the ambient temperature, and the temperature measurement error is small. it can.
However, depending on the installation environment of the system device, etc., there may be an extreme temperature distribution in the ambient temperature of the measuring device. In this case, the temperature balance between the “terminal temperature of the multi-point input CH section” and the “reference junction compensation sensor” Collapses and temperature measurement error increases.

  The present embodiment is an invention relating to a method for compensating for a temperature measurement error in a case where an extreme temperature distribution is present in the ambient temperature of a measuring instrument due to such an apparatus being incorporated.

In FIG. 3, at least two units of moving means 31 and reference contact compensation sensor 32 are used.
Even in such a case, as shown in FIG. 3, the space can be easily attached. By laying out the reference junction compensation sensor 32 at both ends of the terminal block 12 and complementing the measured value of the terminal temperature therebetween, a highly accurate reference junction compensation system can be realized.

  As a result, since a plurality of reference junction compensation sensors can be easily attached, the terminal temperature can be measured with high accuracy.

4A and 4B are explanatory views of the main configuration of another embodiment of the present invention. FIG. 4A is a front view, FIG. 5B is a side view, FIG. 5 is an operation explanatory view of FIG. , 42, the temperature distribution of the measurement terminal 23 and the reference junction compensation sensor 22, (b) is the compensation temperature of the measurement terminal 23 and the reference junction compensation sensor 22 by the compensation plates 41, 42, and (c) is the compensation plate 41, 42. Is a temperature distribution after temperature compensation of the measurement terminal 23 and the reference junction compensation sensor 22 according to FIG.
In the figure, the same symbols as those in FIG. 8 represent the same functions.
Only the difference from FIG. 8 will be described below.

In FIG. 4, the sensor temperature correction plate 41 is arranged corresponding to the reference junction compensation sensor 22 provided on the terminal plate 21 and corrects the temperature of the ambient temperature environment.
The terminal temperature correction plate 42 is arranged corresponding to each predetermined terminal, and corrects the temperature of the ambient temperature environment for each predetermined terminal.

In this case, one sensor temperature correction plate 41 and two terminal temperature correction plates 42 are used.
In this case, the sensor temperature correction plate 41 and the terminal temperature correction plate 42 are provided on the side surface of the terminal plate 21 so as to be orthogonal to the surface of the terminal plate 21.
In this case, the sensor temperature correction plate 41 and the terminal temperature correction plate 42 slide in a direction orthogonal to the surface of the terminal plate.

In this case, the sensor temperature correction plate 41 and the terminal temperature correction plate 42 are made of an aluminum material.
Specifically, in the embodiment of FIG. 4, the reference contact compensation sensor 22 is arranged between 3CH and 4CH in the multipoint measurement terminals 23 from 1CH to 6CH.

  In the above configuration, when the ambient temperature is constant, the multi-point measurement terminal 23 and the reference junction compensation sensor 22 can perform accurate temperature measurement while maintaining temperature balance. However, there is a local heat source A in the vicinity of the temperature measuring device. In this case, due to the influence of the heat source A, as shown in FIG. 5A, temperature differences occur between the multipoint measurement input terminals 23 and the reference junction compensation sensor 22, and the temperature measurement error increases.

  Therefore, in order to correct the temperature distribution of the terminal portion (measurement terminal 23, reference contact compensation sensor 22) by the heat source A, a reference contact temperature correction plate 41 and a terminal temperature correction plate 42 are individually provided below the terminal portion, and the reference As shown in FIG. 4B, the contact temperature correction plate 41 and the terminal temperature correction plate 42 are moved as shown by the arrow B, so that the reference contact temperature correction plate 41 and the terminal temperature correction plate 42 are moved. 5B, the temperature between the terminals 23 and the temperature of the reference contact compensation sensor 22 whose thermal equilibrium has been lost and the temperature of the reference contact compensation sensor 22 are set to the same temperature as shown in FIG. 5C. And correct.

The temperature correction plates 41 and 42 are metals having good heat conduction such as aluminum, and are thermally coupled to the casing 25 to conduct heat of the casing 25 to the correction plates 41 and 42, below the reference contact compensation sensor 22 and the terminal 23. Apply temperature correction from.
The correction plates 41 and 42 are arranged independently of the reference junction compensation sensor unit 22 and the terminal unit 23, and have a structure that balances temperature by moving according to the correction temperature as a structure that can be individually expanded and contracted.

As a result,
When a thermocouple thermometer is arranged in an environment where the local heat source A is installed in a system apparatus, a temperature distribution is generated in the measurement terminal 23 and the reference junction compensation sensor 22 due to the influence of the heat source. There is a problem that the temperature balance between the terminal 23 "of the point input CH section and the" reference contact compensation sensor 22 "is unbalanced and the temperature measurement error increases.

  In this embodiment, after being incorporated into a device having a local heat source A, the temperature correction plate is individually applied to “terminal 23 of multi-point input CH section” and “reference junction compensation sensor 22” according to the influence of the heat source. The temperature measurement error can be reduced by performing temperature correction by 41 and 42.

The above description merely shows a specific preferred embodiment for the purpose of explanation and illustration of the present invention.
Therefore, the present invention is not limited to the above-described embodiments, and includes many changes and modifications without departing from the essence thereof.

It is principal part structure explanatory drawing of one Example of this invention. It is component explanatory drawing of FIG. It is principal part structure explanatory drawing of the other Example of this invention. It is principal part structure explanatory drawing of the other Example of this invention. It is operation | movement explanatory drawing of FIG. It is structure explanatory drawing of the prior art example generally used conventionally. It is principal part explanatory drawing of FIG. It is composition explanatory drawing of the other conventional example generally used conventionally. It is operation | movement explanatory drawing of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Thermocouple 2 Measurement contact 3 Reference contact 4 Measuring instrument 5 Terminal 11 Base printed board 12 Terminal block 13 Reference contact compensation printed board assembly 14 Connector 21 Wiring terminal part 22 Reference contact compensation sensor 23 Measurement input terminal 24 Terminal cover 25 Case 31 moving means 311 electrical circuit components 312 connector 32 reference junction compensation sensor 33 fixing means 41 sensor temperature compensation plate 42 terminal temperature compensation plate A heat source

Claims (7)

In a thermocouple thermometer having a terminal plate reference junction compensation means,
One end is connected to one end of the terminal plate and the other end moves along the terminal plate;
A reference junction compensation sensor provided at the other end of the moving means;
A thermocouple thermometer comprising: fixing means for fixing the reference junction compensation sensor to the terminal plate. The thermocouple thermometer according to claim 1, wherein at least two units of the moving means and the reference junction compensation sensor are used. The thermocouple thermometer according to claim 1, wherein a flexible printed board is used as the moving means. The thermocouple thermometer according to claim 3, wherein an electric circuit component is provided on the flexible printed board. The thermocouple thermometer according to any one of claims 1 to 3, wherein an adhesive is used as the fixing means. The thermocouple thermometer according to claim 4, wherein a double-sided tape is used as the adhesive. The thermocouple thermometer according to claim 4, wherein an adhesive is used as the adhesive.

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