JP2001066188A - Radiation thermometer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To measure accurately the surface temperature of an object to be measured, by a simple operation only of displaying a character or a graphic showing the object to be measured which is a measuring target, on a liquid crystal display and of retrieving it, even if an emissivity of the object to be measured is unknown. SOLUTION: This thermometer is equipped with a memory unit 10 in which a character (or a graphic) showing an object to be measured and an emissivity of the object to be measured are housed, a retrieving means 13 for displaying the character housed in the memory unit 10 on a liquid crystal display 12 and for retrieving the character showing the object to be measured which is a measuring target, a control device 8 for retrieving an emissivity of the object to be measured corresponding to the retrieved character from the memory unit 10, and an operating device 9 for calculating the surface temperature based on the emissivity retrieved by the control device 8 and a radiance from the surface of the object to be measured detected by an infrared sensor 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radiation thermometer for measuring a surface temperature based on the emissivity of an object to be measured and the radiance from the surface of the object to be measured.

[0002]

2. Description of the Related Art A radiation thermometer is based on a spectral emissivity ε (λ) of an object at a measurement wavelength λ and a spectral radiance L (λ) from the surface of the object detected by an infrared sensor. It is common to measure the surface temperature, but the emissivity differs depending on the object to be measured, and the difference in the emissivity affects the reading of the radiation thermometer. It is necessary to reset the emissivity according to the object to be measured.

[0003] In particular, a radiation thermometer used for measuring the surface temperature of various metals in a heat treatment plant or the like or for measuring the surface temperature of various foods or food materials in a food processing plant or the like is a measurement object to be measured. There are many types of objects, and the emissivity may differ significantly depending on the type. Therefore, it is necessary to frequently reset the emissivity according to the type of the measured object.

Therefore, the conventional radiation thermometer is, by definition, zero.
An emissivity adjustment knob or the like is provided that can set the emissivity ε (λ) which is larger and smaller than 1 in 0.01 increments.

[0005]

However, the emissivity differs not only with the object to be measured but also with the same object to be measured depending on the wavelength measured by the radiation thermometer. You must know the emissivity of the object under measurement in the measurement wavelength range of the radiation thermometer to be used.If you do not know the emissivity, use an emissivity table that lists the emissivity of various objects in that wavelength range. For reference, the emissivity of the object to be measured must be checked each time.

In addition, the operation of finely changing the set value of the emissivity in increments of 0.01 using the emissivity adjustment knob or the like is very troublesome, and there is a possibility that the operation may be erroneously set by mistake.

[0007] Recently, a fixed emissivity type radiation thermometer in which the setting of the emissivity cannot be changed at all, and only the three-step rough setting of the standard (standard) / bright (bright) / dark (dark) are possible. Although radiation thermometers can be found, they are not suitable for precise temperature measurement due to poor measurement accuracy.

Accordingly, the present invention is to improve the measurement accuracy of a radiation thermometer by making it possible to accurately set the emissivity by simple operation without knowing the emissivity of an object to be measured without knowing the emissivity. Is a technical issue.

[0009]

In order to solve the above-mentioned problems, the present invention provides a radiation thermometer for measuring a surface temperature based on an emissivity of an object to be measured and a radiance from the surface of the object to be measured. A storage device having a character data storage unit or a graphic data storage unit storing characters or graphics representing the device under test, and an emissivity data storage unit storing the emissivity of the device under test, and character data storage of the storage device Search means for displaying a character or graphic stored in a unit or a graphic data storage unit on a liquid crystal display to search for a character or graphic representing an object to be measured, and the character or graphic searched by the search means A control device that retrieves the emissivity of the device under test from the emissivity data storage unit of the storage device, the emissivity searched by the control device, and the emissivity detected by the infrared sensor Characterized by comprising a calculating device to calculate the surface temperature based on the radiance from the workpiece surface which.

According to the present invention, even if the emissivity of the device under test is not known, characters or graphics representing the device under test are displayed on the liquid crystal display by the search means, and the object to be measured is displayed from among the characters or graphics. When a character or a graphic representing an object is searched, the emissivity of the object to be measured is searched from the emissivity data storage unit of the storage device by the control device, and the object device searched by the control device by the arithmetic device. The surface temperature is accurately calculated based on the emissivity of the measured object and the radiance detected from the surface of the measured object by the infrared sensor.

[0011]

Embodiments of the present invention will be specifically described below with reference to the drawings. FIG. 1 is an external view of a radiation thermometer showing a first embodiment of the present invention, FIG. 2 is a block diagram showing the structure of the radiation thermometer, FIG. 3 is a flowchart showing the operation of the radiation thermometer, FIGS. 5, FIG. 6, FIG. 7, and FIG. 8 show an item list, a character data file, an emissivity data file, an item-character table, and a character-emissivity table stored in the storage device of the radiation thermometer, respectively. FIG. 9 is an external view showing a modification of the radiation thermometer.

FIG. 10 is an external view of a radiation thermometer showing a second embodiment of the present invention, FIG. 11 is a flowchart showing the operation of the radiation thermometer, and FIGS. 12 and 13 respectively show the storage of the radiation thermometer. FIG. 4 is a diagram showing a graphic data file and a graphic-emissivity table stored in the device. Parts corresponding to those in the first embodiment and common parts are denoted by the same reference numerals, and detailed description is omitted.

The radiation thermometer shown in FIG. 1 is mainly used in mining and the like, and includes a condenser 1 such as a lens, an infrared sensor 2 such as a thermopile, an amplifier 3 and an AD converter 4, and a thermometer main body. A control microcomputer 5;
A battery case (not shown) for a power supply and the like are disposed inside the housing 6 made of a flat box-shaped plastic case, and the light collecting device is provided at the front end of the housing 6 facing the light collector 1. A window member 7 serving as a protective cover of the container 1 is fixed.

The microcomputer 5 includes a control device 8 and an arithmetic device 9 that constitute a CPU, a storage device 10, and an input / output port 11. The storage device 10 is configured to store a type of an object to be measured “ A list storage unit for storing the item list of FIG. 4 in which “metal” and “non-metal” and the corresponding item codes “A” and “B” are recorded, and characters representing individual measurement objects to be measured. A character data file of FIG. 5 which is a character data storage unit for storing, and an emissivity data file of FIG. 6 which is a emissivity data storage unit for storing a spectral emissivity of an object to be measured at a measurement wavelength λ of a radiation thermometer; The item-character table of FIG. 7 in which the item code (see FIG. 4) and the corresponding file number of the character data file (see FIG. 5) are recorded, the file number of the character data file (see FIG. 5), and File number (see FIG. 6) and the recorded character of FIG. 8 emissivity data file corresponding to the record -
Emissivity table.

A search means 13 is provided on the upper surface of the housing 6 for displaying characters stored in a character data file of the storage device 10 on the liquid crystal display 12 and searching for a character representing an object to be measured. Have been.

The search means 13 is provided with a menu switch 14 for selecting an item "metal" or "non-metal" of the object to be measured.
a, 14b and characters (file numbers a01 to a11 or b01 to b09) representing the DUT corresponding to the item (code A or B) selected by the menu switch 14a, 14b
Are displayed on the liquid crystal display 12 one by one.

When the menu switch 14a is turned on, the control device 8 refers to the item list of FIG. 4 and the item-character table of FIG. 7 and converts the character data file of FIG. The character data groups with the numbers a01 to a11 are read out and temporarily stored in the internal memory of the storage device 10, and the file number a01 is read from the character data groups.
6 is tentatively output to the liquid crystal display 12 to display the characters of “iron” on the liquid crystal display 12 and, with reference to the character-emissivity table of FIG. 8, the emissivity data of FIG. From the file, the spectral emissivity ε (λ) corresponding to the character of “iron” (file number a01) = “0.
85 "(file number z17), and the retrieved emissivity is stored in a predetermined storage area of the storage device 10.

On the other hand, when the menu switch 14b is turned on, the control device 8 reads the character data group of the file numbers b01 to b09 corresponding to the item code B from the character data file of FIG. And temporarily stores the file number b01 in the character data group.
Is tentatively output to the liquid crystal display 12 and the characters “glass” are displayed on the liquid crystal display 1.
2 and the “glass” from the emissivity data file of FIG. 6 in consideration of the character-emissivity table of FIG.
Spectral emissivity ε corresponding to the character (file number b01)
(Λ) = “0.90” (file number z22) is retrieved, and the retrieved emissivity is stored in a predetermined storage area of the storage device 10.

The object to be measured is "iron"
Or "glass", scroll switch 15
a, 15b, the other characters of the same type temporarily stored in the internal memory of the storage device 10 are displayed on the liquid crystal display 1.
2 is displayed one by one in order, and a character representing the DUT to be measured is searched. At this time, the control device 8
The spectral emissivity ε (λ) corresponding to each character displayed on the liquid crystal display 12 is searched, and the searched emissivity is updated and stored in a predetermined storage area of the storage device 10.

The scroll switch 15a scrolls and displays the character data temporarily stored in the internal memory of the storage device 10 in ascending order of the numerical value of the file number, and the scroll switch 15b scrolls and displays in the reverse order.

When the object to be measured is "aluminum", for example, the menu switch 14a for selecting the "metal" item is turned on, and the scroll switch 1 is turned on.
After the characters "aluminum" are displayed on the liquid crystal display 12 at 5a and 15b, the housing 6 to which the window material 7 is fixed
With its front end facing the surface of the aluminum product to be measured.
The measurement switch 16 provided on the upper surface of the housing 6 is turned on.

Thus, the spectral radiance L (λ) from the surface of the aluminum product is detected by the infrared sensor 2, and the spectral radiance L (λ) and the spectral emissivity of the aluminum updated and stored in the storage device 10 are stored. ε (λ) = 0.30 (file number z0
1), the arithmetic unit 9 calculates the surface temperature of the aluminum product to be measured, and calculates the calculated temperature (for example, “34”).
0 ° C. ”) is displayed on the liquid crystal display 12 as shown in FIG.

Note that a reset switch 17 for clearing data displayed on the liquid crystal display 12 and data temporarily stored in the internal memory of the storage device 10 is provided on the upper surface of the housing 6.
And a power switch 18 for turning on and off the power.

Next, the operation of the radiation thermometer shown in FIGS. 1 and 2 will be described with reference to the flow chart of FIG. 3. First, in step (1), the control device 8 sets the menu switch 14
The switch 14a is turned on when the switch 14a is turned on. In step (2), the character data shown in FIG. 5 is referred to with reference to the item list shown in FIG. 4 and the item-character table shown in FIG. A character data group (file numbers a01 to a11) representing the object to be measured of "metal" (item code A) is searched from the file, and in step (3), the searched character data group is stored in the internal memory of the storage device 10. Temporarily store, step (4)
Then, only the character of "iron" of the file number a01 is provisionally displayed on the liquid crystal display 12, and in the next step (5),
Considering the character-emissivity table in FIG. 8, the character “iron” (file number a01) is obtained from the emissivity data file in FIG.
Then, the spectral emissivity .epsilon. (. Lambda.) = "0.85" (file number z17) corresponding to the emissivity is retrieved, and the retrieved emissivity is stored in a predetermined storage area of the storage device 10 in step (6).

If it is determined in step (1) that the menu switch 14a is not turned on, the process proceeds to step (7) to determine whether or not the menu switch 14b is turned on. Returning to step (1), when it is turned on, the process proceeds to step (8), and the character data file of FIG. 5 is referred to by referring to the item list of FIG. 4 and the item-character table of FIG. Non-metallic "
A character data group (file numbers b01 to b09) representing the device under test of (item code B) is searched, and in step (9), the searched character data group is temporarily stored in the internal memory of the storage device 10 and step (9). Move to (4) and the steps
In (4), only the character of "glass" of the file number b01 is provisionally displayed on the liquid crystal display 12, and then step (5)
The spectral emissivity ε (λ) corresponding to the “glass” character (file number b01) displayed on the liquid crystal display 12 from the emissivity data file of FIG. 6 with reference to the character-emissivity table of FIG. = “0.90” (file number z22), and the retrieved emissivity is stored in a predetermined storage area of the storage device 10 in step (6).

Next, the process proceeds from step (6) to step (10) to determine whether or not the measurement switch 16 is turned on. If the measurement switch 16 is not turned on, the process proceeds to step (11). It is determined whether or not the reset switch 17 is turned on. When the reset switch 17 is turned on, the data temporarily stored in the display of the liquid crystal display 12 or the internal memory of the storage device 10 is determined in step (12). Erase and return to step (1).

If it is determined in step (11) that the reset switch 17 is not turned on, the process proceeds to step (13).
It is determined whether or not the scroll switch 15a is turned on. When the scroll switch 15a is turned on, in step (14), the "iron", "iron oxide", "iron" temporarily stored in the internal memory of the storage device 10 are determined. Each character (file number a01 to a11) such as "cast iron" and "aluminum" or each character (file number b01 to b09) such as "glass", "ceramic", and "plastic" is searched in file number order, and
In (4), the searched characters are scroll-displayed on the liquid crystal display 12.

On the other hand, if it is determined in step (13) that the scroll switch 15a is not turned on, the process proceeds to step (15) to determine whether the scroll switch 15b is turned on. In the next step (16), the characters (file numbers a01 to a11 or b01 to b09) temporarily stored in the internal memory of the storage device 10 are searched in the reverse order of the file numbers, and in step (4) Then, the searched characters are scroll-displayed on the liquid crystal display 12.

In this step (4), the liquid crystal display 1
When, for example, the character “aluminum” is displayed in FIG. 2 as shown in FIG. 1, in step (5), the character “aluminum” is read from the emissivity data file in FIG. Spectral emissivity ε corresponding to (file number a04)
(Λ) = “0.30” (file number z01) is retrieved, and the retrieved emissivity is updated and stored in a predetermined storage area of the storage device 10 in step (6).

Then, when the measuring switch 16 is turned on in the next step (10), the spectral radiance L (λ) from the surface of the object to be measured is detected by the infrared sensor 2 in step (17). In (18), the spectral radiance L (λ) and
The spectral emissivity ε (λ) stored in the storage device 10 = “0.3
0 '' and the surface temperature is calculated, and in step (19),
The calculated surface temperature (for example, “340 ° C.”) is displayed on the liquid crystal display 12 as shown in FIG.

Next, at step (20), it is determined whether or not the reset switch 17 is turned on. When the switch 17 is turned on, at step (21), the liquid crystal display 12 is turned on.
And the character data and emissivity data temporarily stored in the internal memory of the storage device 10 are deleted, and the process returns to step (1).

As described above, the radiation thermometer of FIG. 1 can be used even if the measurer does not know the emissivity of the object to be measured.
By a simple operation of searching the character representing the measured object by the search means 13 and displaying it on the liquid crystal display 12,
The emissivity of the object to be measured is automatically retrieved from the emissivity data file of the storage device 10, and the surface is measured based on the emissivity and the radiance from the surface of the object detected by the infrared sensor 2. Since the temperature is calculated, there is no danger of setting the emissivity incorrectly, and the temperature measurement accuracy is high.

The radiation thermometer shown in FIG.
The characters representing the device under test are displayed on the liquid crystal display 12 one by one, but the present invention is not limited to this. For example, as shown in FIG. And scroll switches 21a and 21b for moving the cursor 20 to the display position of each character.

In the case of FIG. 9, the control device 8 retrieves the emissivity corresponding to the character displayed at the position where the cursor 20 is moved from the emissivity data file of FIG. 6, and stores the retrieved emissivity. When the measurement switch 16 is turned on, the display on the liquid crystal display 12 is cleared and displayed on the liquid crystal display 12 at the position where the cursor 20 is moved, while being updated and stored in a predetermined storage area of the device 10. Emissivity corresponding to characters and infrared sensor 2
The surface temperature calculated based on the radiance from the surface of the object to be detected detected in step (1) is displayed.

If the object to be measured can be represented by a figure, a figure representing the object to be measured is stored in the storage device 10 instead of characters, and the figure is displayed on the liquid crystal display 12. May be.

Next, the radiation thermometer shown in FIG. 10 is suitable for use in a food processing factory or a food service facility, and is installed inside a housing 6 made of a gun-shaped plastic case, as shown in FIG. Optical device 1, infrared sensor 2, amplifier 3, AD
A converter 4, a microcomputer 5, and the like are provided, and a window member 7 serving as a protection plate of the light collector 1 is attached to a front end of the housing 6.

The storage device 10 of the microcomputer 5 includes a graphic data file shown in FIG. 12 which is a graphic data storage unit storing a graphic representing an object to be measured such as a food or foodstuff to be measured. 13 in which the file numbers (c01 to c05) and the file numbers of the corresponding emissivity data files (see FIG. 6) are recorded.

Outside the housing 6, a search means 13 for searching for a figure stored in the figure data file of FIG. 12 and a liquid crystal display for displaying the figure searched by the search means 13 are provided at the rear end side. 12 and a reset switch 17 are provided, and a grip 22 and
A trigger type measurement switch 16 attached to the grip 22 is provided.

The retrieval means 13 reads out the graphics stored in the graphics data file shown in FIG. 12 and, from among them, a search switch 23 for temporarily displaying the graphics of "fish" of the file number c01 on the liquid crystal display 12. A scroll switch 24a for scrolling and displaying each figure read from the figure data file by the search switch 23;
24b.

Next, the operation of the radiation thermometer shown in FIG. 10 will be described with reference to the flowchart of FIG. 11. First, in step (1), it is determined whether or not the search switch 23 has been turned on. When turned on, step
Going to (2), "fish", "meat", "vegetables", "bread" and "tempura" stored in the graphic data file of FIG.
The graphic data (file numbers c01 to c05) are read out and temporarily stored in the internal memory of the storage device 10. In step (3), the graphic data of "fish" (file number c01) is provisionally output to the liquid crystal display 12. Then, the fish figure is automatically displayed on the liquid crystal display 12.

Then, in step (4), the measuring switch 1
6 is turned on, and the measurement switch 16
Is turned on, the radiance L (λ) from the surface of the object to be measured is detected by the infrared sensor 2 in step (5), and the detected value is temporarily stored in the internal memory of the storage device 10. ), The figure of the fish displayed on the liquid crystal display 12 (file number c01) from the emissivity data file as shown in FIG.
Emissivity ε (λ) corresponding to “= 0.97” (file number z
29), and the emissivity is temporarily stored in the internal memory of the storage device 10 in step (7).

In step (8), the surface temperature is calculated based on the emissivity and radiance temporarily stored in the storage device 10. In step (9), the calculated surface temperature is stored in the liquid crystal display 12. indicate.

On the other hand, in step (4), the measurement switch 16
If is not turned on, the process proceeds to step (10) to determine whether or not the reset switch 17 is turned on. When the reset switch 17 is turned on, in step (11),
The display on the liquid crystal display 12 and the graphic data temporarily stored in the storage device 10 are deleted, and the process returns to step (1).

If the reset switch 17 is not turned on in step (10), the process proceeds to step (12),
It is determined whether or not the scroll switch 24a is turned on, and if the switch 24a is turned on, step (13)
Then, the graphic data temporarily stored in the storage device 10 is output to the liquid crystal display 12 in the order of file numbers, and the graphic is scroll-displayed on the liquid crystal display 12 in step (3).

On the other hand, if it is determined in step (12) that the scroll switch 24a is not turned on, the process proceeds to step (14) to determine whether the scroll switch 24b is turned on. ,step 1
In 5), each figure data temporarily stored in the storage device 10 is output to the liquid crystal display 12 in the reverse order of the file number, and
In step (3), each figure is displayed on the liquid crystal display 12.
To scroll display.

In this step (3), as shown in FIG. 10, for example, a figure of "tempura" (file number c05) is displayed on the liquid crystal display 12, and in the next step (4), the measurement switch 16 is turned on. In step (5), the radiance L (λ) from the surface of the object to be measured is detected by the infrared sensor 2 and the detected value is temporarily stored in the internal memory of the storage device 10, and in step (6), 13, the emissivity .epsilon. (. Lambda.) = "0.96" (file number) corresponding to the "tempura" figure displayed on the liquid crystal display 12 from the emissivity data file as shown in FIG. z28) is retrieved, and in step (7), the emissivity is temporarily stored in the internal memory of the storage device 10, and the process proceeds to step (8).
Then, the surface temperature is calculated based on the emissivity and the radiance, and the calculated surface temperature (for example, “80 ° C.”) is displayed on the liquid crystal display 12 in step (9).

Next, the process proceeds from step (9) to step (16) to determine whether or not the reset switch 17 is turned on. When the switch 17 is turned on, step (17)
Then, the display on the liquid crystal display 12 and the emissivity data and radiance data temporarily stored in the storage device 10 are deleted, and the process returns to step (1).

[0048]

According to the present invention, even if the measurer does not know the emissivity of the object to be measured, the character or graphic representing the object can be displayed on the liquid crystal display and searched. There is a very excellent effect that the surface temperature of the object can be measured accurately and accurately by a simple operation.

[Brief description of the drawings]

FIG. 1 is an external view of a radiation thermometer showing a first embodiment of the present invention.

FIG. 2 is a block diagram showing the structure of a radiation thermometer.

FIG. 3 is a flowchart showing the operation of the radiation thermometer.

FIG. 4 is a diagram showing an item list of a storage device;

FIG. 5 is a diagram showing a character data file in a storage device.

FIG. 6 is a diagram showing an emissivity data file of a storage device.

FIG. 7 is a diagram showing an item-character table of a storage device;

FIG. 8 is a diagram showing a character-emissivity table of a storage device;

FIG. 9 is an external view showing a modification of the radiation thermometer.

FIG. 10 is an external view of a radiation thermometer showing a second embodiment of the present invention.

FIG. 11 is a flowchart showing the operation of the radiation thermometer.

FIG. 12 is a diagram illustrating a graphic data file of a storage device.

FIG. 13 is a diagram illustrating a figure-emissivity table of a storage device.

[Explanation of symbols]

 2 Infrared sensor 8 Control device 9 Computing device Storage device 12 Liquid crystal display 13 Search means 14 a Menu switch 14b Menu switch 15a Scroll switch 15b Scroll switch 16 Measurement switch 19 Search switch Cursor 21a Scroll switch 21b Scroll switch 23 Search switch 24a Scroll switch 24b Scroll switch

Claims (4)

[Claims] A radiation thermometer for measuring a surface temperature based on an emissivity of an object to be measured and a radiance from a surface of the object to be measured, wherein a character data storage section storing a character or a graphic representing the object to be measured is provided. A storage device having a graphic data storage unit and an emissivity data storage unit storing the emissivity of the device under test (1
0) and the characters or figures stored in the character data storage unit or graphic data storage unit of the storage device (10) are displayed on the liquid crystal display (12), and the characters or figures representing the object to be measured are displayed. Searching means for searching; and a control device for searching the emissivity of the device under test corresponding to the character or figure searched by the searching means from the emissivity data storage section of the storage device. (8) an arithmetic unit (9) for calculating the surface temperature based on the emissivity searched by the control device (8) and the radiance from the surface of the measured object detected by the infrared sensor (2) A radiation thermometer comprising: 2. The search means (13) represents a menu switch (14a, 14b) for selecting an item of the device under test and a device under test belonging to the item selected by the menu switch (14a, 14b). Scroll switch (15) that displays characters or graphics on the LCD display (12) one by one
The radiation thermometer according to claim 1, comprising: a, 15b). 3. A search switch (19) for simultaneously displaying a plurality of characters or figures representing an object to be measured on a liquid crystal display (12), and a cursor at a display position of each of the characters or figures. 2. A radiation thermometer according to claim 1, wherein said radiation thermometer comprises a scroll switch (21a, 21b) for moving said (20). 4. The liquid crystal display (12) displays a surface temperature calculated by the arithmetic unit (9).
The radiation thermometer according to 2 or 3.