JPS62287125A - Thermocouple input digital converting method - Google Patents

Abstract

PURPOSE:To easily make room temperature corrections by simple hardware constitution by processing a signal regarding a thermocouple input and a room- temperature correction signal obtained by measuring the room temperature after converting them into digital signals. CONSTITUTION:One of electromotive forces generated by plural thermocouples 1 is selected optionally by an analog multiplexer 4 and converted by the 1st A/D converter 5a into a digital signal, which is sent to a computing element 6. A voltage signal obtained by a room-temperature measuring circuit 2, on the other hand, is converted by the 2nd A/D converter 5b into a digital signal, which is sent to the computing element 6. The computing element 6 processes data obtained by those digital signals and makes proper room-temperature corrections of the thermocouple inputs to output effective data. Consequently, the number of room-temperature measuring circuits is decreased greatly and the room temperature corrections are easily made by the simple hardware constitution.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a thermocouple input digital conversion method that can easily perform room temperature correction of thermocouple input.

[Conventional technology]

Figure 2 is a block diagram for explaining the conventional thermal 1-to-person digital conversion method. It is a vessel.

Next, the operation will be explained. The thermoelectromotive force (α pressure) generated by the thermocouple 1 has a characteristic that immediately before the adder 3, it is reduced by an amount corresponding to the room temperature. Therefore, it is necessary to correct this subtracted amount by some means, but this correction is performed by the room temperature measuring circuit 2 and the adder 3. The voltage signal corrected in this manner is transmitted by the analog multiplexer 4, converted into a digital signal by the digital converter 5, and used as valid data.

[Problem that the invention seeks to solve]

Since the conventional thermocouple manual digital conversion method is configured as described above, it is necessary to perform room temperature correction for each data input from multiple thermocouples, and the room temperature correction circuit and associated components are required. There were problems such as requiring a large number of controllers and complicating the hardware configuration used for room temperature correction.

This invention was made to solve the above-mentioned problems, and its purpose is to provide a thermocouple input digital conversion method that can easily perform room temperature correction without complicating the hardware configuration. do.

[A precautionary measure to resolve the problem]

The thermocouple input digital conversion method according to the present invention is as follows.

The data sent from multiple thermocouples is transmitted through the analog multiplexer in the housing without correction.

In addition to digitally converting this, the room temperature correction signal obtained from room temperature measurement is also digitally converted, and then these digitally converted signals are processed to perform room temperature correction of the thermocouple input. This is what I did.

[Operation] The thermocouple input data in this invention is input to the analog multiplexer as it is without room temperature correction, is digitized, and then input to the arithmetic unit.Meanwhile, the room temperature correction signal obtained by room temperature measurement is also After being digitized separately, it is input to this arithmetic unit. Then, room temperature correction is performed by this g generator.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. 1st
In the figure, 1 is a thermocouple, 2 is a room temperature correction circuit, 4 is an analog multiplexer, 5a is a first converter, 5b is a second f converter, and 6 is an arithmetic unit.

Next, the operation will be explained. Each thermogenic force (voltage) generated by the plurality of thermocouples 1 is.

An arbitrary point is selected by the analog multiplexer 4, transmitted to the first converter 5a, and converted into a digital signal.
After being converted, it is sent to the arithmetic unit 6.

On the other hand, the voltage signal obtained by the room temperature measurement circuit 2 is converted into a digital signal by the second 0 converter 5b and sent to the digital converter 6.

The arithmetic unit 6 then performs arithmetic processing on the data provided by these digital signals in order to correct the room temperature of the thermocouple input, and outputs valid data that has been appropriately corrected for the room temperature.

In the above embodiment, the first line converter 5a (for thermocouple) and the second line converter 5b (for room temperature measurement) are shown as two converters, but the analog multiplexer 4 Depending on how you use it, you can use only one of these.

〔Effect of the invention〕

As described above, according to the present invention, the signal related to the thermocouple input transmitted by the analog multiplexer and the room temperature correction signal obtained by measuring the room temperature are converted into digital signals and then subjected to arithmetic processing. So, room temperature 1
The number of constant circuits can be greatly reduced, making it simple...
- There is an effect that room temperature correction can be easily performed due to the hardware configuration.

[Brief explanation of the drawing]

FIG. 1 is a telekinetic block diagram for explaining a thermocouple input digital conversion method according to an embodiment of the present invention, and FIG. 2 is a block diagram for explaining a conventional thermocouple input digital conversion method. 1 is a thermocouple, 2 is a room temperature correction circuit, 4 is an anacog multiplexer, 5a and 5b are first . The second line converter 6 is an arithmetic unit. In addition, in FIG. 1, the same reference numerals indicate the same 2 or corresponding parts. Patent Applicant Mitsubishi Electric Law Company Agent Patent Attorney 1) Hiroshi Sawa (2 others)

Claims (1)

[Claims] In a thermocouple input digital conversion method of digitally converting a plurality of thermocouple input data after room temperature correction using an analog multiplexer, inputting the plurality of thermocouple input data before room temperature correction to the analog multiplexer; It is characterized by performing room temperature correction of the thermocouple input by digitally converting the output signal from the sensor, digitally converting the room temperature correction signal obtained from room temperature measurement, and performing arithmetic processing on these digitally converted signals. Thermocouple input digital conversion method.