JPS581731B2 - Multi-point temperature measuring device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a multi-point temperature measuring device. A multi-point temperature measuring device requires a terminal board for inputting the thermoelectromotive force of a plurality of thermocouples.

The thermocouple is connected to the input terminal either directly or through a compensating conductor, thus creating a reference junction near the input terminal.

The temperature of the reference junction is detected by a temperature sensing element and used as a cold junction compensation signal. However, it is cumbersome to detect the temperature of the reference junction for each thermocouple, so it is necessary to The temperature of the reference junction is made to be constant.

A conventional example of isothermalizing multiple reference junctions is to connect a normal conductor to the input terminal to which a thermocouple or its compensation conductor is connected via an internal compensation conductor of the same type, and to connect this internal compensation conductor to the normal conductor. There is one in which the connection point is used as a reference junction and is concentrated in a reference temperature tank.

However, in such conventional devices, the internal compensation lead wire must be selected according to the type of thermocouple, which is complicated, and the internal compensation lead wire connected to the normal lead wire cannot be easily replaced, so it is difficult to select it once it has been adopted. It is difficult to replace the thermocouple with a different type later.

In other words, the terminal board cannot be standardized because the combination with a specific thermocouple is determined.

An object of the present invention is to provide a multi-point temperature measuring device using a simple terminal device that is suitable for standardization in which combinations with thermocouples are not specified.

The present invention arranges a plurality of input terminals inside a closed housing, groups these into horizontal rows, and performs cold junction compensation at the internal temperature of the housing corresponding to the vertical position of each group. be.

The present invention will be explained below with reference to the drawings.

FIG. 1 is a conceptual block diagram of an embodiment of the present invention.

In FIG. 1, TIS is a multi-point temperature measuring device, which is composed of an input terminal device (terminal board cubicle) TBC and a data processing device (field control cubicle) FCC.

A plurality of thermocouples TC are connected to the input terminal device TBC through compensation conductor cables CW.

A signal is usually provided from the input terminal device TBC to the data processing device FCC via a conductor cable RW.

The data processing device FCC is a digital data processing device using a microprocessor, and processes a given signal to obtain temperature measurement values at multiple points.

The data processing device FCC has a tabletop operator control device DOC.
are connected, making man-machine communication possible.

The data processing unit FCC connects to other control stations FCS and operators' terminals for comprehensive monitoring via the communication line F-BUS.
It is connected to the station OPS and forms part of the overall control system.

The detailed configuration of the multi-point temperature measuring device TIS is shown in FIG.

As shown in FIG. 2, the input terminal device TBC is configured by mounting a plurality of input terminal boards TB in a housing (cubicle).

Each strand of the compensation conductor cable CW is connected to each terminal of the input terminal board TB.

Each terminal is collectively connected to a connector, and from this connector each signal is transmitted to the data processing device F through a normal conductor cable RW.
This will be communicated to CC.

The data processing device rCC is constructed by mounting a control nest CN including a microprocessor serving as the central part of data processing and a common power supply, and a plurality of multiplexer nests MN in a housing.

Normal conductor cable RW for multiplexer nest MN
A plurality of input signals are provided through.

A plurality of input signals are converted one by one into digital signals and held in the multiplexer nest MN.

The digital signal held in the multiplexer nest MN is subjected to arithmetic processing such as cold junction compensation and linearization by the microprocessor of the control nest CN, and becomes a temperature measurement value.

The temperature measurements are displayed on a display on the tabletop operator controller DOC or operator's station OPS.

FIG. 3 shows the detailed structure of the input terminal board TB.

In FIG. 3, a is a plan view, and b is a sectional view taken along line AA'.

In FIG. 3, 1 is a collective terminal, 2 is a connector, 3 is a mounting base, and 4 is a base.

The collective terminal 1 and the connector 2 are mounted on a mounting base 3.

The mount 3 is mounted on the base 4.

On the base 4, there is another set of collective terminals 1' and connectors 2'.
and the mounting base 3' assembly is attached.

The interiors of the mounting bases 3, 3' are hollow, and a printed wiring board 5 of normal conducting wires for connecting each terminal of the collective terminal 1 and the connector 2''f is provided therein.

A temperature sensing element 6 is mounted on the printed wiring board 5 and connected to the connector 2 through printed wiring.

A thermocouple TC is connected to each terminal of the collective terminal 1 through a compensation conductor, and a reference junction is formed at each terminal.

The electromotive force of each thermocouple and the detection signal of the temperature-sensitive element are transmitted to the data processing device FCC by a normal conductor cable connected to the connector 2.

Such an input terminal board TB is installed in the housing of the input terminal device TBC in such a position that each terminal of the collective terminal 1 is horizontal and the base 4 is vertical.

This installed state is shown in FIG. Since the input terminal board TB does not have a heat generation source, the flow of air is almost stagnant inside the casing in which it is mounted.

Therefore, the temperature difference between the terminals arranged horizontally becomes negligible, and the temperature difference between the collective terminal 1 on the front side of the mounting base 3 and the temperature sensing element 6 on the back side can also be ignored. Become.

Therefore, each reference junction belonging to the same column is made substantially equal in temperature, and its temperature is detected by a common temperature sensing element 6.

The data processing device FCC performs cold junction compensation based on the temperature detection signal of the temperature sensing element 6.

Although there may be a temperature difference based on temperature distribution in the vertical direction inside the housing, the temperature of each example reference junction is detected by a temperature sensing element provided on the back side of each example.

When the temperature distribution is known in advance, it is not necessary to provide a temperature sensing element for each reference junction row, but by providing each temperature sensing element on the input terminal boards corresponding to the upper, middle, and lower rows of the housing. The number can be reduced and the temperatures of the other stages can be calculated by analogy in the data processing device FCC.

Since the temperature of the reference junction is made equal in this way, there is no need to use an internal compensating conductor or a special reference temperature tank as in the conventional case.

Therefore, any type of thermocouple can be connected to each terminal, and the configuration is simplified.

In other words, the input terminal device is suitable for standardization.

The present invention arranges a plurality of input terminals in a closed housing, groups them in horizontal rows, and performs cold junction compensation at the internal temperature of the housing corresponding to the vertical position of each group. , a multi-point temperature measuring device using an input terminal device suitable for simple standardization of a configuration in which the combination with a thermocouple is not specified can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a conceptual block diagram of an embodiment of the present invention, FIG. 2 is a detailed diagram of the main part of FIG. 1, FIG. 3 is a block diagram of an input terminal board, and FIG. 4 is a block diagram of an input terminal device. TIS...Multi-point temperature measuring device, TBC...
...Input terminal device, FCC...Data processing device, TC...Thermocouple, CW...Compensation lead wire, RW...Normal lead wire, DOC... ...Tabletop operator control unit, FCS ... System station, OPS ... Operator's station, F-BUS ... Data communication line, TB- ...
...Input terminal board, CN...Control nest, MN...Multiplexer nest, 1.
...Collection terminal, 2...Connector, 3...
...Mounting stand, 4...Base, 5...
・Printed board, 6...Temperature sensing element.

Claims (1)

[Claims] 1. A multi-point temperature measurement device consisting of an input terminal device to which a plurality of thermocouples are connected and a data processing device that processes signals received from the input terminal device, the input terminal device having a closed housing, Inside this housing, there are multiple input terminals arranged horizontally in rows and vertically in multiple stages, connectors that aggregate the input terminals in each row, and connectors arranged at multiple vertical locations inside the housing that receive detection signals. The data processing device has a plurality of temperature sensing elements that are applied to the data processing device, and the data processing device has a multi-point calculation circuit that calculates the temperature of the measured object based on the thermoelectromotive force signal that is applied through the connector and the detection signal of the temperature sensing device. Temperature measuring device.