JPH06241914A - Reference contact compensating device - Google Patents

Abstract

PURPOSE:To compensate the temp. of a reference contact with high accuracy by connecting a wiring board having the conductive plate electrically connected to a terminal plate having a plurality of terminals provided on one side thereof to the terminal plate on the other side thereof and providing a temp. element in the vicinity of the conductive plate. CONSTITUTION:Terminals 21-25 are provided at one end of a terminal plate 11 and thermocouple wires are connected to the head parts of one ends of the terminals by terminal screws 21a-25a. The other ends of the terminals 21-25 are extended and the card edge 30 of a printed wiring board 3 is inserted in the recessed part provided at the other end of the terminal plate 1. Therefore, the conductive plates 41, 45 of the edge 30 are electrically connected to the terminals 21-25 and, further, thermocouple outputs connected to the terminals 21-25 are taken out through patterns 51-55. Temp. elements 61, 62 for compensating the temp. of a reference contact are provided in contact with the conductive plates 41, 45 corresponding to the terminals 21, 25 and the outputs of the temp. elements 61, 62 are taken out of patterns 50a, 50b. Since the elements 61, 62 are thermally connected to the terminals 21, 25 through the conductive plates 41, 45, the reference contact of each thermocouple is compensated extremely well.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reference junction compensation device such as a thermocouple.

[0002]

2. Description of the Related Art When a plurality of terminals to which a thermocouple or the like is connected are provided on a terminal plate for temperature measurement, a representative temperature at one point is usually measured to compensate for a reference junction temperature.

[0003]

However, if only one point of temperature is used as a representative, it is not sufficient when there is a temperature distribution due to the structure of the terminal board, and each terminal is subject to temperature fluctuations due to changes in ambient temperature. Therefore, there was a problem that the temperature distribution varied and the temperature compensation was not sufficient.

SUMMARY OF THE INVENTION In view of the above points, an object of the present invention is to provide a reference contact compensating device capable of performing more accurate reference contact temperature compensation.

[0005]

According to the present invention, there is provided a wiring having a terminal plate having a plurality of terminals connected to one side and a conductive plate connected to the other side of the terminal plate and electrically connected to the terminals. A reference contact compensating device comprising a substrate and a temperature element for compensating a reference contact provided in the vicinity of the conductive plate, and a plurality of terminals provided on the terminal plate and one of the terminals. And two or more temperature elements provided corresponding to the parts, and a calculating means for calculating the difference between each output of the temperature elements and the zero-point output to calculate the temperature of each terminal of the terminal board and perform reference contact compensation. The reference contact compensation device is provided with.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a structural explanatory view showing an embodiment of the present invention.

In the figure, reference numeral 1 denotes a terminal plate, and a plurality of terminals 21, 22, 23, 24, 25, ... Are provided on one side thereof, and one end of the terminals 21, 22, 23, 24, 25 ,. A thermocouple wire (not shown) is attached to the heads of the terminal screws 21a, 2
2a, 23a, 24a, 25a, ... Are connected. The other end of each terminal 21, ... Extends, and the card edge 30 of the printed wiring board 3 is inserted into the concave portion on the other side of the terminal board 2. As a result, the card edge portion 3 of the printed circuit board 3
0 electrically conductive plates 41, 42, 43, 44, 45, ... Are electrically connected to the respective terminals 21, 22, 23, 24, 25, .. Further, wiring patterns 51, 52, 53, 54, 5.
The thermocouple outputs connected to the terminals 21, 22, ... Are taken out via 5 ,.

Further, corresponding to some terminals 21 and 25, temperature elements 61 and 6 such as transistors for compensating the reference junction temperature.
2 is provided in close proximity to the conductive plates 41 and 45,
Wiring patterns 50a, 5 on the opposite side of the printed wiring board 3
An electric output corresponding to the temperature is taken out from 0b. The temperature element is resin-molded or the like for insulation.

As described above, since the temperature elements 61 and 62 are in isothermal contact with the terminals 21 and 25 through the conductive plates 41 and 45 and are made to be isothermal, the reference junction compensation of each thermocouple is extremely excellent. . This temperature element may be provided for each thermocouple, but may be provided for some terminals and the temperature of each of the other terminals may be calculated to perform reference junction compensation. In this regard, FIG.
Will be described with reference to.

Output V corresponding to temperatures T1 and T2 of temperature elements 61 and 62 provided corresponding to the mth and nth terminals, respectively.
m, Vn and zero point output are changeover switches S1 and S
2 and So are sequentially switched and selected, and A is passed through the buffer 71.
The signal is AD converted by the -D converter 81 and stored in the memory of the calculating means 9 such as a microcomputer, and the calculating means 9 takes the difference between the outputs Vm and Vn and the zero-point output Vo = 0, and then the terminals. For example, if the temperature output for compensating the reference junction temperature with respect to is linearly approximated, it is obtained by the calculation of the following equation.

Vk = (Vm−Vn) (k−n) / (m−n) + Vn (1) Here, the output of the Kth terminal is Vk, but the buffer 7
If there is a measurement error Δ such as a drift in the circuit such as 1, the output and the zero output are Vm + Δ, Vn + Δ, and Δ, respectively, but the equation (1) is Vk = {(Vn + Δ) − (Vn−Δ)} (k−n) /
(M−N) + {(Vn + Δ) −Δ} = (Vm−Vn)
(K−n) / (m−n) + Vn, and in particular, the influence of the bias error of the term Vn is removed.

On the other hand, thermocouple inputs e1, e2, ... And zero point input eo = 0 from terminals 21, 22, 23, 24 ,.
Are changeover switches S11, S12, S13, S14, ...
It is switched and selected by Sn1, Sn2, So1, and So2, amplified by the amplifier 72, AD-converted by the AD converter 82, and input e1, e2 ... And zero point eo by the calculating means 9.
And the circuit error of the amplifier 72 and the like is removed, and the reference contact compensation signal Vk obtained by the equation (1) corresponding to each terminal is added to each output ek to perform the reference contact compensation. Obtain the output ek + Vk. This temperature compensation calculation is
The outputs ek and Vk are always executed periodically every time they are fetched.

The positions of the temperature compensating temperature elements 61 and 62 are set so that when the terminals of the terminal board 1 are arranged vertically, the positions of the upper and lower terminals correspond to the positions of any other terminals. It may be three or more, and the arithmetic expression is
Various things will do. It is also possible to measure and correct the temperature distribution in advance.

[0014]

As described above, according to the present invention, since the temperature element for reference point compensation is provided close to the conductive plate of the wiring board for connecting to the terminal of the terminal board and is made isothermal, the temperature detection accuracy is improved. Is high, the influence of surrounding changes is small, and the reference junction compensation accuracy is high. Also, since two or more temperature elements are provided and the temperature of each terminal is calculated by taking the difference from the zero point output, even if there is a circuit error, it will be eliminated and a more accurate compensation output will be obtained, resulting in a temperature distribution. Is less affected, and the compensation accuracy is improved.

[Brief description of drawings]

FIG. 1 is a structural explanatory view showing an embodiment of the present invention.

FIG. 2 is a structural explanatory view showing an embodiment of the present invention.

[Explanation of symbols]

1 terminal board 21, 22, 23, 24, 25 terminal 21a, 22a, 23a, 24a, 25a terminal screw 3 printed wiring board 30 card edge 41, 42, 43, 44, 45 conductive plate 51, 52, 53, 54, 55, 50a, 50b Wiring pattern 61, 62 Temperature element 71 Buffer 72 Amplifier 81, 82 AD converter 9 Arithmetic means

Claims (2)

[Claims] 1. A wiring board having a terminal board to which a plurality of terminals are connected on one side, a conductive board connected to the other side of the terminal board and electrically connected to the terminals, and a wiring board adjacent to the conductive board. And a temperature element for compensating the reference contact, which is provided as described above. 2. A plurality of terminals provided on a terminal board, and two or more temperature elements provided corresponding to a part of the terminals,
A reference contact compensation device, comprising: a calculation unit that calculates a difference between each output of the temperature element and a zero-point output to calculate the temperature of each terminal of the terminal board and performs reference contact compensation.