JP2002365144A - Compensation structure for cold junction - Google Patents

Abstract

PROBLEM TO BE SOLVED: To allow a temperature to be measured precisely. SOLUTION: A space isolated from the outside air is provided inside a connector 4 connected to an internal circuit 13 of a temperature regulator 5, and a connection part (cold junction) for a thermocouple element wire or a compensation lead wire 2, and a temperature measuring element 12 are stored in the space.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermocouple input device, which measures the temperature of a thermocouple connection terminal (cold junction) of the device, and detects a thermocouple signal equivalent to that when the cold junction is placed at 0.degree. The present invention relates to a cold-junction compensation structure suitable for performing cold-junction compensation so as to be provided to a device.

[0002]

2. Description of the Related Art FIG. 10 shows a schematic configuration of a conventional example of a cold junction compensation structure of a temperature controller using a thermocouple.
In this cold junction compensation structure, the compensating lead wire 22 connected to the thermocouple 21 is connected to the internal circuit 24 of the temperature controller 23 via the terminal block and the connector 25, and at a position near the terminal block and the connector 25. A temperature measuring element 26 such as a temperature measuring resistor or a thermistor for detecting a temperature is provided, and the internal circuit 24 performs cold junction compensation.

[0003]

The terminal block and the connector 25 for connecting the compensating lead wire 22 and the temperature controller 23 must be installed at a location on the periphery of the temperature controller 23 which is exposed to the outside air. A temperature measuring element 26 for measuring the temperature of the terminal block or the connector 25 serving as a thermocouple connection terminal (cold junction) of the controller 23 as accurately as possible is also arranged as close to the terminal block and the connector 25 as possible. Therefore, the device is exposed to the outside air, and depending on the use conditions, the influence of the outside air temperature, the air current, and the like on the cold junction compensation cannot be neglected, which is a harmful effect on the temperature measurement with high accuracy.

The present invention has been made in view of such a point, and it is a main object of the present invention to provide a cold junction compensation structure capable of measuring a temperature with high accuracy.

[0005]

In order to achieve the above object, the present invention has the following configuration.

That is, the cold junction compensation structure of the present invention is a cold junction compensation structure in a device that performs cold junction compensation by measuring the temperature of the connection portion with a thermocouple with a temperature measuring element, and shuts off outside air. A housing, the housing having a first connection portion connected to a thermocouple element wire or a compensation lead wire from the thermocouple, and a second connection portion connected to an internal circuit of the device; An internal terminal of the first connection portion is made of the same material as a thermocouple wire or a compensating lead wire. The internal terminals of the first and second connection portions are connected in a housing, and the temperature measurement is performed. The element is connected to the internal terminal of one of the connection portions in the housing.

Here, the housing only needs to be able to block the outside air and suppress its influence, and may be configured to be externally attached to the device or may be configured to be housed inside the device. You may.

According to the present invention, the first terminal connected to the thermocouple wire or the compensating conductor is made of the same material as the thermocouple wire or the compensating wire, so that the first terminal portion in the housing is provided. The connection between the cold junction and the second terminal is a cold junction, and the temperature of the cold junction is measured by a temperature measuring element also arranged in the housing. As a result, the cold junction compensation is performed with high accuracy.

In another embodiment of the present invention, the first and second connecting portions are connectors.

According to the present invention, while the housing can be attached to and detached from the device via the connector, the thermocouple wire or the compensating conductor can be easily connected to or separated from the housing. Thereby, the assembling workability and the maintainability are excellent, and the practical convenience is high.

A cold junction compensation structure according to the present invention is a cold junction compensation structure in an apparatus for performing cold junction compensation by measuring the temperature of a connection portion with a thermocouple with a temperature measuring element, wherein the temperature measuring element has an internal structure. And a first connector connected to a thermocouple element wire or a compensating lead wire from the thermocouple and a second connector connected to an internal circuit of the device on a peripheral wall thereof. Connector.

According to the present invention, the internal terminal of the first connector connected to the thermocouple wire or the compensating lead wire serves as a cold junction, and the temperature of the cold junction is measured by a temperature measuring element arranged in the housing. Therefore, the cold junction and the temperature measuring element are located in a portion that is not exposed to the outside air temperature or the air current, and the high-precision cold junction compensation is performed.

In a preferred aspect of the present invention, the connector of the housing is connected to an internal circuit of the device via a cable.

According to the present invention, it is possible to dispose the apparatus at a distant position so as not to be affected by the heat generation of the apparatus.

In another embodiment of the present invention, the device is a temperature controller.

According to the present invention, the temperature can be measured with high accuracy, so that the temperature can be controlled with high accuracy.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic configuration diagram of a cold junction compensation structure of a temperature controller according to the present invention, and FIG. 2 is a perspective view showing a cold junction compensation structure of the temperature controller.

In these figures, reference numeral 1 denotes thermocouples installed at a plurality of temperature measuring points, and a compensating lead wire 2 derived from each thermocouple 1 is collected in a harness 3 and serves as a housing for shutting off outside air. It is connected to a multipoint type temperature controller 5 via a connector 4. The connector 4 includes the connectors 6a, 6
The harness 3 of the compensating lead 2 is detachably connected to the connector 4 via connectors 7a and 7b, while being connected detachably to the temperature controller 5 via b. The internal terminal of the connector 7a on the compensation lead 2 side is made of the same material as the compensation lead 2.

FIG. 3 shows the internal structure of the connector 4. The body 8 of the connector 4 has a hollow box shape, and a connector 6b as a second terminal connected to the connector 6a of the temperature controller 5 is provided below the hollow body 8. A connector 7b as a first terminal connected to a connector 7a to which the harness 3 is connected is provided on an upper portion of the body 8, and an internal terminal of the connector 7b is made of the same material as the compensating conductor 2. ing.

The internal terminal 9 of the connector 6b and the internal terminal 10 of the connector 7b are connected by a conductor 11 made of the same material as the compensating conductor 2.

Therefore, in this embodiment, the cold junction serves as a connection between the conductor 11 and the internal terminal 9 of the connector 6b.

A temperature measuring element 12 such as a thermistor for measuring the temperature at the cold junction is connected to and supported by another internal terminal 9 of the connector 6b.

Each terminal of the connector 6a on the temperature controller side is
The internal circuit 13 of the temperature controller 5 is connected to the internal circuit 13 via a pattern, wiring, or the like on the substrate, thereby forming a cold junction compensation circuit.

According to the above configuration, the connection point between the conductor 11 and the connector 6b in the body 8 becomes the cold junction e, and the cold junction e and the temperature measuring element 12 are exposed to the outside air temperature or airflow. Connector 4 with stable temperature conditions
Therefore, the cold junction compensation is performed with high accuracy.

Although not shown, the body 8 of the connector 4 may have a split structure such as an upper cover and a lower cover, and may have a structure in which a connector is mounted on one side. , Or other structures.

As another embodiment of the present invention, as shown in FIG. 4, the internal terminal 9 of the connector 6b and the connector 7
b of the internal terminal 10 and the conductor 11 of the same material as the compensating conductor 2
Instead of the connection, a simple copper wire 30 may be used to connect the temperature measuring element 12 to the internal terminal 10 of the connector 7b. As shown in FIG. 5, the internal terminal 9 of the connector 6b and the internal terminal 10 of the connector 7b are connected to the circuit board 31.
6 may be connected through the conductor pattern of FIG.
As shown in (5), the temperature measuring element 12 'may be mounted on the circuit board 31'.

As another embodiment of the present invention, a resin is sealed in the body 8 of the connector 4 so as to increase the heat capacity and to make the temperature between the cold junction and the temperature measuring element uniform. You may.

Further, in each of the above-described embodiments, the internal terminal 10 of the connector 7b above the connector 4 is
However, as another embodiment of the present invention, as shown in FIG. 7, the internal terminal 10 'of the upper connector 7b' is a normal conductor,
A connector 7b 'of a normal material may be used. In this case, since the connection point of the internal terminal between the connector 7a to which the compensating lead wire 2 from the thermocouple 1 is connected and the connector 7b 'is a cold junction, it is not affected by the outside air.

In each of the above embodiments, the connector 4 is directly connected to the temperature controller 5 via the connector 6a. However, as another embodiment of the present invention, for example, as shown in FIG. Alternatively, the connecting device 4 and the temperature controller 5 may be connected by a normal cable 35, so that the connecting device 4 can be arranged at a position not affected by the heat generated by the temperature controller 5.

It is to be noted that a thermocouple element may be used in place of the compensating conductor 2 described above, and the present invention may be embodied as follows.

(1) As shown in FIG. 9, it is also possible to carry out the embodiment in which the compensating lead wire 2 (or thermocouple wire) is directly connected to the connector 6b of the connector 4.

(2) If necessary, each of the thermocouples may be connected to the temperature controller 5 via a dedicated connector 4 containing the temperature measuring element 12 in the internal space.

(3) The compensating conductor or the thermocouple wire is guided inside the device, and a housing is arranged inside the device. A configuration may be adopted in which the temperature element is housed and arranged so as not to be affected by the outside air and the heat from the heating element of the device.

[0035]

As described above, according to the present invention, the connecting portion for the thermocouple, that is, the so-called cold junction, and the temperature measuring element for measuring the temperature thereof are located at a portion which is not exposed to the outside air temperature or the air current. , It is possible to perform high-precision cold junction compensation,
As a result, even in measurements where high resolution is required,
Highly accurate temperature measurement with excellent reproducibility and stability is possible. Further, by applying the present invention to a temperature controller, high-precision temperature control becomes possible.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing a cold junction compensation structure of a temperature controller according to the present invention.

FIG. 2 is a perspective view showing a cold junction compensation structure of the temperature controller according to the present invention.

FIG. 3 is a front view showing the internal structure of the connector.

FIG. 4 is a schematic configuration diagram showing another embodiment of a cold junction compensation structure.

FIG. 5 is a schematic configuration diagram showing another embodiment of the cold junction compensation structure.

FIG. 6 is a schematic configuration diagram showing another embodiment of the cold junction compensation structure.

FIG. 7 is a schematic configuration diagram showing another embodiment of the cold junction compensation structure.

FIG. 8 is a schematic configuration diagram showing another embodiment of the cold junction compensation structure.

FIG. 9 is a schematic configuration diagram showing another embodiment of the cold junction compensation structure.

FIG. 10 is a schematic configuration diagram showing a conventional cold junction compensation structure.

[Explanation of symbols]

 2 Compensating conductor 4 Connector (housing) 5 Temperature controller 6a, 6b Connector 7a, 7b connector 9 Internal terminal 10 Internal terminal 11 Conductor 12 Temperature measuring element 13 Internal circuit

Claims (5)

[Claims] 1. A cold junction compensation structure for a device that performs cold junction compensation by measuring the temperature of a connection portion with a thermocouple with a temperature measuring element, comprising: a housing that blocks outside air; A first connection portion connected to a thermocouple element wire or a compensation lead wire from the thermocouple, and a second connection portion connected to an internal circuit of the device, and an internal terminal of the first connection portion. Is made of the same material as the thermocouple wire or the compensating lead wire, and the internal terminals of the first and second connection portions are connected in the housing, and the temperature measuring element is one of the ones in the housing. A cold junction compensation structure, wherein the cold junction compensation structure is connected to an internal terminal of a connection portion. 2. The cold junction compensation structure according to claim 1, wherein said first and second connection portions are connectors. 3. A cold-junction compensation structure in a device for performing cold-junction compensation by measuring the temperature of a connection portion with a thermocouple by using a temperature-measuring element, wherein a housing in which the temperature-measuring element is disposed is provided. Wherein the housing has, on its peripheral wall, a first connector connected to a thermocouple wire or a compensating wire from the thermocouple and a second connector connected to an internal circuit of the device. Cold junction compensation structure. 4. The cold junction compensation structure according to claim 1, wherein the connector of the housing is connected to an internal circuit of the device via a cable. 5. The apparatus according to claim 1, wherein the device is a temperature controller.
5. The cold-junction compensation structure according to any one of items 1 to 4.