JPH01210830A - Infrared-ray temperature distribution measuring instrument - Google Patents

Abstract

PURPOSE:To reduce the influence of a reflection and to exactly measure a temperature extending from a low temperature area to a room temperature area by switching plural optical filters for allowing a specific wavelength area to transmit through in front of an infrared-ray detector. CONSTITUTION:Plural optical filters for allowing a specific wavelength area to transmit through are provided in front of an infrared-ray detector 15. In such a state, in accordance with a kind of object to be measured 10, the filters 17, 18 are switched 20. That is, when the object to be measured 10 is, for instance, other than glass whose reflection factor is small or an object being equivalent thereto, the filter 17 for allowing infrared rays of about 8-13mum to transmit through is used as a filter, and when the object to be measured 10 is, for instance, glass or an object being equivalent thereto, the filter 18 for allowing infrared rays of about 5-8mum is used as a filter. In such a way, at the time of using the filter 17, the temperature of a low temperature area can be measured, and at the time of using the filter 18, the temperature of a room temperature area can be measured.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an infrared temperature distribution measuring device that measures the temperature of an object by detecting infrared rays emitted from an object depending on the temperature.

[Summary of the invention]

This invention is an infrared temperature distribution measuring device that measures the temperature of an object by detecting infrared rays emitted from an object depending on the temperature. By installing multiple optical filters and switching these optical filters according to the object to be measured, it is possible to reduce the influence of reflection and make it possible to measure temperature in the normal temperature range by 6J, while also making it possible to measure temperature in the low temperature range. Mo-
■It was designed to be Noh.

[Conventional technology]

Various types of infrared temperature distribution measuring devices have been proposed to measure the temperature of an object by detecting infrared rays emitted from an object depending on the temperature. Infrared temperature distribution measuring device (1nSb PoSe) using quantum type detector, approx.
13 μN quantum infrared temperature distribution measuring device (IIgCd
There are three types of infrared temperature distribution measuring equipment using thermal detectors of all wavelengths (approximately 2 to 15 μm). In contrast to the previous #2, thermal infrared temperature distribution measuring devices have lower sensitivity and slower response, so this device is actually often used to measure the temperature at one point, and is generally used to measure temperature distribution. is inappropriate.

All of the quantum infrared temperature distribution measuring devices were developed in response to the so-called "atmospheric window" shown in FIG. 5, and are widely used for measuring temperature distribution.

Here, it can be seen that those with a sensitivity wavelength of 5 to 8 μm are missing, but this is because, as can be seen from Figure 5, water vapor absorption is large in this region, and therefore, for example, remote control from aircraft or artificial satellites is It is rarely used in sensing, etc., and therefore does not exist as a conventional product.

(Problems to be Solved by the Invention) By the way, the quantum infrared temperature distribution measuring device described above, which has a sensitivity wavelength of 8 to 13 μm, detects long wavelengths for general temperature measurement. As is obvious, this device is of good quality and can measure temperatures down to low temperatures (for example, -50"C). However, when using this device to measure temperature, it is especially important to measure the temperature of a building outdoors for external wall diagnosis, etc. In such cases, if there is a large temperature distribution around the object of reflection, the influence of reflection from the high-temperature object cannot be ignored in many cases.

For example, as shown in Figure 3, transparent glass or frosted glass! The infrared temperature distribution measuring device (2
) to measure the temperature of the glass (11), the infrared temperature distribution measuring device (2
) within the detection angle range of the high temperature object (3
), the temperature measurement results indicate that glass (1)
A reflected image of the high temperature object (3) appears on the temperature distribution of the glass (1), which has the disadvantage that the temperature of the glass (1) cannot be accurately measured. This can be seen from the fact that in the transmittance, emissivity, and reflectance of the glass shown in FIG. 4, the reflectance becomes large in the vicinity of wavelengths of 8 to 13 μm.

In addition, in the case of the quantum infrared temperature distribution measuring device with a sensitivity wavelength of 3 to 5 μm, as shown in Figure 4, the reflectance is small in the vicinity of the wavelength of 3 to 5 μm, but the transmittance is large (accordingly, the radiation rate is getting smaller), 3-5
It is not desirable to use the wavelength of μ seaweed, and 4.8 to 5.
It uses infrared radiation in a narrow range of 2 μm. As a result, the reflected image of a high-temperature object as described above is unlikely to appear, but in this region the wavelength is short and it is not possible to capture a lot of infrared energy, so the S/N ratio deteriorates, and the temperature measurement range is approximately 100 degrees Celsius or higher. It has the disadvantage that it cannot measure temperature at room temperature or lower temperature fiJI range.

This invention was made in view of these points, and it is possible to accurately measure the temperature of glass or an equivalent object in the room temperature range by reducing the influence of reflection to a negligible extent, and to switch the optical filter. This provides an infrared temperature distribution measuring device that can measure temperatures even in a low temperature region lower than the normal temperature region.

[Failure to solve the problem]

This invention is based on the object to be measured, which emits radiation depending on the temperature (
Detecting infrared rays from lO) with an infrared detector (15),
In an infrared temperature distribution measurement device that measures the temperature of an object to be measured (10), a plurality of optical filters (17, 18) that transmit a specific wavelength range are installed in front of an infrared detector (15).
), and is configured to switch between a plurality of optical filters depending on the object to be measured (10).

(Function) In front of the infrared detector (15) that detects infrared rays, a specific wavelength range, for example, sensitivity is set at about 8 to 13 μm and about 5 to 8 μm.
A plurality of optical filters (17, 18
) will be established. Then, these optical filters (17°18) are connected to the switching device (2
0). That is, if the object to be measured +11 is other than glass with a low reflectance or an object equivalent thereto, an optical filter that transmits infrared rays of about 8 to 13 μm is used, and if the object to be measured (1) is glass or an object equivalent to this, for example, Approximately 5 to 8 as an optical filter for an equivalent object
A material that transmits μm infrared rays is used. This results in
Optical filter that transmits infrared rays of approximately 8 to 13 μm <1
7), it is possible to measure temperatures in low temperature ranges, for example, down to about -50°C, and when using an optical filter (18) that transmits infrared rays of about 5 to 8 μm, the influence of reflection is reduced to a negligible level. Alternatively, it is possible to measure the temperature of objects in the room temperature range, including objects equivalent to this.

〔Example〕

Hereinafter, one embodiment of the present invention will be described in detail based on FIGS. 1 to 4.

FIG. 1 shows the configuration of this embodiment, and in the figure,
(It)) is the object to be measured, (11) is the object to be measured (
(12) is a chopper for chopping the infrared energy and converting it into an alternating current signal; (13) is a motor for driving the chopper (12); (14) is a motor for driving the chopper (12); Relay lens, (15)
is an infrared detector (HgCdTe) that converts chopped infrared energy into an electrical signal, such as a voltage signal;
(I6) is an output terminal.

In this embodiment, for example, in front of the chopper (12), a rotary holding member (1) is provided with a number of optical filters (17) and (18) so that the approximate center thereof is located on the optical path of infrared rays.
9). The optical filter (17) has a sensitivity wavelength of approximately 8
The optical filter (18) is configured to transmit infrared rays having a sensitivity wavelength of about 5 to 8 µm. Then, the rotation holding member (19) is rotated by the switching device (2o), and the optical filter (1'/) and (1
8) is switched depending on the type of the object to be measured (10) and placed on the infrared light path.

Fig. 2 is a top view of the rotation holding member (19) to which the optical filters (17) and (18) are attached; However, as long as its approximate center does not deviate from the optical path of infrared rays, it may be at any position.

Now, if the object to be measured (1o) is an object with a low reflectance other than glass or an equivalent object, such as frost on a refrigerator, the switching device (20) switches the rotation holding member (19). The optical filter (17) is rotated to be placed on the infrared light path. Then, the infrared rays from the frost as the object to be measured (10) are condensed by the objective lens (11), and only the infrared rays with a sensitivity wavelength of approximately 8 to 13 μm are transmitted through the optical filter (17). infrared detection W (1) through the relay lens (14).
5) is detected. Here, the signal is converted into an electrical signal and taken out to an output terminal (16), and after being amplified by an amplifier (not shown), its temperature distribution is displayed on a monitor.

In this way, in this case, the optical filter (17) only transmits infrared rays with a sensitivity wavelength of about 8 to 13 μm, so for the region of about 5 to 8 μm, the sensitivity wavelength is long < S/N ratio is improved. It is possible to measure temperatures in a low temperature range, for example, down to about -50°C. Further, in this case, the object to be measured (lO) has a low reflectance, so it is not affected by reflection.

Next, when the object to be measured (10) is glass or an object equivalent thereto, the rotating member (19) is rotated by the switching device (2o) to place the optical filter (18) on the infrared light path. Then, the infrared rays from the glass as the object to be measured (10) or an object equivalent thereto are focused by the objective lens (11), and the infrared rays are collected by the optical filter (18) with a sensitivity wavelength of approximately 5 to 8.
Only infrared rays of μm are transmitted through, are nayopped by a chopper (12), and detected by an infrared detector (15) via a relay lens (14). Then, the temperature is converted into electrical power No. 46, taken out to the output terminal (I6), and, as shown in the figure, after being amplified by an amplifier, its temperature distribution is displayed on a monitor.

In this way, in this case, the optical filter (18) only transmits infrared rays with a sensitivity wavelength of about 5 to 8 μm, and when this sensitivity wavelength is about 5 to 8 μm, the reflectance is as shown in Figure 4. Because it is low, there is no influence of reflection, and 3 to 5
Since the sensitivity wavelength is longer than in the μ- region and a large amount of infrared energy can be obtained, the S/N ratio can be improved, resulting in temperature measurement i''IJ performance in the room temperature region.

By the way, an optical filter (■8) is placed on the infrared light path,
When the temperature of transparent glass or frosted glass was measured using this device as shown in FIG. 3, the reflected image of the high temperature object could be reduced to a negligible level.

As described above, in this embodiment, an optical filter (17) that transmits infrared rays with a sensitivity wavelength of approximately 8 to 13 μm is used, and an optical filter (18) that transmits infrared rays with a sensitivity wavelength of approximately 5 to 8 μm is used.
If the object to be measured (+11) is something with a low reflectance other than glass such as frost on a refrigerator or an equivalent object, an optical filter (17) should be placed on the infrared light path. In the case of glass or an equivalent object, an optical filter (18) is placed on the optical path of the infrared rays, so that the influence of reflection is reduced to a negligible level, and the same device can be used to e.g. It becomes possible to measure the temperature of objects with low reflectance other than glass or objects equivalent thereto in the low temperature region of -50° C., and it also becomes possible to accurately measure the temperature of glass or objects equivalent thereto in the room temperature region.

In the above embodiment, the rotation holding member (19) is provided with two optical filters (17) and (18). However, more optical filters may be provided. Furthermore, the position of the rotation holding member (19) to which the optical filters (17) and (18) are attached is not limited to the case shown in FIG. It is okay to be in the position of duty in front of.

〔Effect of the invention〕

As described above, according to the present invention, a plurality of optical filters that transmit a specific wavelength range are provided in front of the infrared detector, and the temperature is measured by switching these optical filters depending on the object to be measured. Therefore, the influence of reflection can be reduced to a negligible extent, and the temperature can be accurately measured from a low temperature range to a normal temperature range using the same device.

[Brief explanation of the drawing]

Figure 1 is a configuration diagram showing an embodiment of the present invention, Figure 2 is a plan view of the main parts of the invention, Figure 3 is a thermal image measurement diagram of glass, and Figure 4 is the transmittance and emissivity of glass. 9 Diagram showing reflectance,
FIG. 5 is a diagram showing the absorption rate of the atmosphere. (10) is the object to be measured, (11) is the objective lens, (1
2) is a chopper, (13) is a motor, (14) is a relay lens, (15) is an infrared detector, (1'/). (18) is an optical filter, (19) is a rotation holding member, (
20) is a switching device.

Claims (1)

[Scope of Claims] An infrared temperature distribution measuring device that measures the temperature of the object by detecting infrared rays emitted from the object depending on the temperature with an infrared detector, the infrared detector An infrared temperature distribution measuring device characterized in that a plurality of optical filters that transmit a specific wavelength range are provided in front of the device, and the plurality of optical filters are switched depending on the object to be measured.