JP2531797B2 - Environmental monitoring equipment - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an indoor environment monitoring technique and an environment monitoring device based on the output of an infrared detector. The present invention relates to a technique effectively used when an uncomfortable indoor environment is detected and a control signal for an alarm device or an air conditioner is output.

[Prior Art] Conventionally, in order to create a comfortable indoor environment, various air conditioners have been proposed in which a temperature sensor or a temperature sensor is used to detect an indoor state to adjust a cooling / heating apparatus.

However, the conventional general air conditioner controls the temperature based on a detection signal from a contact type temperature sensor such as a thermistor arranged in the main body of the apparatus or in the vicinity thereof. In other words, the temperature of the air around the sensor is regarded as the indoor average temperature for control.

On the other hand, regarding fire detection, there are provided fire detectors that use photocells, bimetals, and television cameras, but photocells are sensitive to wavelengths in the ultraviolet range, so light from sunlight, electric lights, etc. There is a drawback that it is easy to malfunction. On the other hand, the bimetal type is too low in sensitivity and poor in effectiveness. Further, in the method of monitoring with a television camera, it is difficult to judge the situation, the number of installed cameras is too large, and in addition, it is necessary for humans to constantly monitor, so it is difficult to obtain a predetermined result.

Under these circumstances, the infrared ray detection method for detecting infrared rays emitted from a flame has recently been greatly admired. In such an infrared detection method as well, one step forward from the simple method of judging a fire when simply detecting infrared light of a certain level or more, is to check whether the output signal level of the infrared detector is increasing for a certain time or more. A fire detector incorporating an identification circuit has been proposed.
No. 56-7196).

In order to improve reliability, the infrared radiation
Efforts have been made to develop a technology for detecting separately in different wavelength bands and determining whether there is a fire based on such information. One of them is using two types of sensors, a sensor that detects visible or near infrared and a sensor that detects infrared, and it is visible or near compared to the radiant intensity in the infrared, such as the radiation from a light. When the radiation intensity in the infrared region is high, it is a system that judges non-fire.

The other method is to detect the spectral distribution characteristic of a flame. Generally, the spectrum distribution of infrared rays emitted from an infrared radiation source without a flame follows Planck's law as shown by the solid lines A and C in Fig. 2, and the peak value of the spectrum shifts to the shorter wavelength side as the temperature of the heating object rises. .
In contrast, infrared emitting objects with flames exhibit other unique properties. That is, as shown by a solid line B in FIG. This is caused by a phenomenon known as CO ₂ molecular resonance radiation,
It shows a high peak around 4.3 μm. Therefore, in principle, a flame can be detected by detecting a peak near a wavelength of 4.3 μm due to the CO ₂ molecule resonance radiation.

Therefore, some attempts have been conventionally proposed to capture the 4.3 μm wavelength peak. For example,
No. 50-2497 detects the radiation dose at 4.3 μm and two wavelengths before and after it, and judges that it is a flame when the radiation dose at 4.3 μm and the other two wavelengths exceeds a certain value. Further, JP-A-57-96492 proposes to detect the occurrence of flame by determining whether or not a valley exists between two convex portions.

[Problems to be Solved by the Invention] Regarding the indoor environment control by an air conditioner or an air conditioner, the temperature felt by a person in the room is the most important factor. However, in addition to the temperature of the air that is directly in contact with human skin, the temperature that the human body feels is radiant heat that the skin absorbs infrared rays emitted from the indoor space and feels. For example, when there is radiant heat from a heater or a window, it feels like burning to the human body, and when the window or wall absorbs the radiant heat from the human body, it feels like bottom cooling. Therefore, the conventional method that controls the environment only by the output temperature of the contact-type temperature measuring device such as the thermistor that detects the air in contact with the indoor temperature measuring device cannot provide a truly comfortable environment for humans. There was a problem.

On the other hand, with regard to fire detection, the conventional method that determines that there is no fire when the radiant intensity in the visible or near-infrared region is large compared to the radiant intensity in the infrared region, such as electric light, is less likely to cause false alarms due to ordinary electric lights. However, even if it is a heating element other than a fire, such as an electric heater, if it does not emit visible or near-infrared rays or if it is weak, it is judged to be a fire and an incorrect alarm is issued, so its application is often restricted.

In the method of detecting the radiation dose at the wavelength 4.3 μm and the two wavelengths before and after that, and judging it as a flame when the radiation dose at 4.3 μm and the other two wavelengths exceeds a certain value, it is not possible to detect the flame. If possible, it is not possible to detect whether the flame is from a fire or a useful heat source. That is, there is a defect that a false alarm is generated by a flame of a gas range, a gas stove, or the like.

An object of the present invention is to detect a change in an indoor environment including the occurrence of a fire, to realize a comfortable indoor environment for humans, and to detect a fire with high sensitivity and very few false alarms based on a useful heat source. To provide a simple environment monitoring device.

[Means for Solving the Problem] The present inventors considered that the occurrence of a fire was also a change in the environment and considered the environmental monitoring technology and the fire detection technology in the living space in the same dimension.

As a result, in order to create an environment in which a person in a room feels most comfortable, not only is the air temperature in the room monitored, but the radiant temperature is mainly monitored and the air temperature is also monitored to control the environment. Is the best method, and since an infrared detector can be used to monitor the radiation temperature and the method of using an infrared detector is also excellent for fire detection, it is possible to use an infrared detector. We got the idea that it is possible to control the indoor environment and detect fire based on the output of one detector.

Therefore, we examined environmental control and fire detection based on radiation temperature in more detail.

As a result, indoor radiation temperature can be calculated from the ratio of the outputs of multiple infrared detectors, and by installing a contact-type temperature measuring device such as a thermistor, the human body feels as if it were in the detection space. The temperature can be monitored and the environment can be controlled so that the human body feels comfortable.

Normally, the indoor environment temperature is about 300 ° K (23 ° C)
Therefore, the emission wavelength peak is around 10 μm.
Therefore, it is desirable to provide the infrared detector with a bandpass filter having a transmission center wavelength of 10 μm. On the other hand, if the environment to be monitored is equipped with a heating appliance that does not accompany a fire, such as an electric heater, if the environment is monitored only with a 10 μm bandpass filter, the temperature will rise partially due to the electric heater. Even if it is, it is determined that the entire environmental temperature has risen. Therefore, monitoring is performed when the transmission center wavelength of the bandpass filter is around 4 μm.

Furthermore, 4 μm of infrared rays emitted from the environment is sufficiently smaller than 10 μm when there is no heating equipment, but 4 μm when there is a red-heated heating equipment such as an electric heater.
Infrared rays near m are also emitted with the same intensity as 10 μm. Therefore, the intensity of the wavelength around 10 μm becomes large, and 4 μm
It can be judged that the electric heater is heating when the strength of m also becomes large, and that the temperature of the entire environment is rising when 4 μm is smaller.

On the other hand, there are the following phenomenological differences between fire and non-fire.

That is, in the case of a heat source other than a fire, the heat generation area and the temperature reach a steady state within a constant period or a few minutes. For example, in heating appliances and the like, the heat generation area is constant, and the temperature reaches a steady state within a few minutes. In addition, matches, lighters, etc., not only have constant temperature and heat generation area, but also disappear in seconds or minutes.

On the other hand, in the case of a fire, both the heating area and the temperature increase,
In addition, there is a characteristic that it shows an increasing tendency even after several minutes. FIG. 3 (A) shows the temperature change in the process from the smoldering state to the fire, and FIG. 3 (B) shows the change of the heat generation area. Here, TF is the point of time of inflammation. Further, in the case of a fire that does not go through a smoldering state, for example, a fire such as an arson, the temperature change and the heat generation area change after the TF point in FIGS. 3A and 3B are shown.

Furthermore, in the case of fire, if the emitted infrared rays are separated into multiple wavelength bands ranging from short to long wavelengths, the detection output of each wavelength band increases with time, and the change in the ratio of the detection output also has a unique behavior. Indicates. In other words, while the magnitude of the detection output reflects the area and temperature of the heat-generating part,
Since the ratio of the detection output reflects the temperature of the heat-generating part, in the case of a smoldering fire, the detection output of each wavelength and the ratio of the detection output both tend to increase gradually, and at the time of transition to a flaming fire Thus, the detection output and its ratio increase rapidly.
After that, since the temperature rise tends to be saturated with the increase in the area of the heat source, the detection output increases, but the ratio becomes almost constant. Then, at the time of the transition to the flaming fire, the resonance emission of the CO ₂ molecule increases remarkably, and the intensity increases as the fire area increases. On the other hand, in the case of a flame other than a fire, such a temporal change is not observed after reaching a steady state.

The present invention has been made based on the above consideration, and a bandpass filter that separates infrared rays emitted from a monitoring space into a plurality of wavelength bands, and an infrared ray that detects each infrared ray that has passed through each bandpass filter. An infrared detector including a detector, one of the plurality of wavelength bands including a resonance radiation wavelength band of CO ₂ molecules, and an infrared detector for detecting a wavelength range of 1 to 16 μm, and infrared detectors of the respective wavelength bands. The present invention proposes an environment monitoring device comprising a signal processing device for determining the fire occurrence and calculating the radiation temperature of the monitoring space based on the temporal change of the output of the above and the ratio of these detection outputs.

[Operation] According to the above-mentioned means, the environmental temperature is controlled by constantly monitoring the radiation temperature through the measurement of a common physical quantity called the radiation temperature. Regarding the fire detection, the radiation temperature is abnormal when the fire occurs. By judging by detecting the pattern and resonance emission of CO ₂ molecules, whether the temperature change of the entire environment is due to electric heaters, gas heaters, stoves, or other heating appliances with flames, or a fire. It is possible to accurately determine whether a fire has occurred, and it is possible to control a comfortable environment for the human body and detect a fire without malfunction.

[Embodiment] FIG. 1 shows a state of a room in which the environment monitoring apparatus of the present invention is installed.

In this embodiment, an air conditioner 51 is attached to the upper part of the indoor wall, and a temperature measuring device 52 such as a thermistor is attached to the lower part thereof.

Further, an infrared detecting device 53 using a pyroelectric infrared sensor is attached downward at the center of the ceiling of the room, and the infrared detecting device 53, the air conditioner 51 and the temperature measuring device 52 are connected by a cable 54. The signal processing device 50 is connected to a signal processing device 50 such as a microcomputer installed in a guard room, etc., and the signal processing device 50 calculates the radiation temperature in the room based on the output of the infrared detection device 53, and outputs the temperature data to the air conditioning device 51. send. Then, the microcomputer of the air conditioner 51 appropriately adjusts the temperature and amount of air blown based on the radiation temperature data and the detection signal from the temperature measuring device 52 to create a comfortable indoor environment.

Further, the signal processing device 50 activates the alarm device 20 arranged in an alarm room, a corridor, or the like when it determines that a fire has occurred based on the detection signal from the infrared detection device 53.

However, instead of incorporating a microcomputer in the air conditioner 51, a signal processing device 50 that monitors the entire building forms a control signal for the air conditioner 51 based on the outputs of the temperature detector 52 and the infrared detector 53, and outputs the control signal. You may

FIG. 4 shows a schematic configuration of an embodiment of the infrared detecting device and an environment control system based on the output of the infrared detecting device.

The infrared detection device 53 includes a rotary chopper 1 that periodically divides infrared light, bandpass filters 2a, 2b, 2c, 2d each including, but not limited to, four optical filters having different transmission bands, and each bandpass. Infrared detectors 3a, 3b, which detect transmitted infrared rays in association with the filters 2a-2d,
It has 3c and 3d. The center wavelengths of the transmission bands of the bandpass filters 2a to 2d are as follows:
For example, the filter 2a is 2-3 μm, and the filter 2b is 3-4 μm.
m, filter 2c is 4 ~ 5.5μm, filter 2d is 8 ~ 15μ
The transmission wavelength band is 0.1 for each.
~ 1.5 μm. Of these filters 2a-2d,
One is selected that transmits the resonance radiation wavelength band (4.3 μm) of CO ₂ molecules. Here, the filter 2c is adapted to transmit the resonance radiation wavelength band of CO ₂ molecules. Also,
The wavelength band from 5.5 to 8 μm should be avoided because it is highly absorbed by water vapor in the air. The number of divided wavelength bands is not limited to four as described above, but can be divided into any number of two or more, but 5 to 6 is sufficient for practical use.

The optical filter is a multilayer film formed by alternately vacuum-depositing ZnSe, ZnS, Ge, or another dielectric on a substrate such as Si, and the film pressure is determined according to the target transmission wavelength band.

As the infrared detectors 3a to 3d, a semiconductor infrared detector,
Although any of a thermopile and a pyroelectric infrared detector can be used, a semiconductor infrared detector is not suitable because it requires cooling, and a thermopile or a pyroelectric infrared detector is desirable, and a pyroelectric one is particularly preferable. . Further, the chopper 1 can be omitted when a thermopile is used for the infrared detector.

The pyroelectric detector is a differential type detector that responds only to a change in temperature, and is suitable for the device of the present invention that measures an increase in temperature. Pyroelectric detectors include lithium tantalate and PbxZryO ₃
An electrode is formed on the front surface and the back surface of a thin plate of a pyroelectric body typified by 1) by vapor deposition or the like. Further, in the case of detecting the near infrared region around the wavelength of 1 μm, a Si photodiode can be used.

A pulse motor, a DC motor, or the like is suitable for rotationally driving the chapper 1, but in the case of a DC motor, a rotation detector 4 such as a photo interrupter for detecting the rotation speed of the chopper is required. When the chopper is driven by the pulse motor, the number of rotations can be known from the drive circuit, so that the photo interrupter is unnecessary.

Output signals from the infrared detectors 3a to 3d and chopper rotation detection signals are processed by the signal processing circuit 10. The signal processing circuit 10 calculates the magnitude of the output from each infrared detector 3a to 3d, the relative ratio of those outputs, and their time change, and determines whether the target infrared source is a fire or not based on the result. However, when it is judged that there is a fire, the drive signal of the alarm device is output.

FIG. 5 shows a configuration example of the signal processing circuit 10. Output signals from the infrared detectors 3a to 3d are amplified by amplifier circuits 11a, 11b, 11c, 11
d and amplified to the desired level. Further, the rotation detection signal from the photo interrupter 4 is input to the phase shift circuit 12, and the synchronization signals SINφ and COS are out of phase with each other by 90 degrees.
φ is output. The outputs from the amplifier circuits 11a to 11d are synchronous detection circuits 13a _{1 to} 13 in synchronism with the synchronization signals SINφ and COSφ.
It is supplied to d ₁ , 13a _{2 to} 13d ₂ and detected. Synchronous detection circuit 1
The detection outputs of 3a _{1 to} 13d ₁ and 13a _{2 to} 13d ₂ are square circuits.
14a ₁ is ~14d _1, 14a ₂ ~14d ₂ with the square, then added by the adder 15a~15d for each channel, is the square root operation in square root circuits 16 a to 16 d. In this way, by performing synchronous detection separately for the synchronizing signals that are 90 degrees out of phase, and taking the root mean square of those detection outputs, the phase deviation due to the positional deviation between the chopper and the infrared detector can be eliminated. To be removed.

The outputs of the square root calculators 16a to 16d are A / D converters 17a to 17d.
Is A / D converted by and input to the microcomputer 18,
Signal processed. In the embodiment of FIG. 5, the root mean square is calculated by the analog calculator, but the signal detected synchronously is
If D-converted and input to the microcomputer, the microcomputer can also perform the root mean square. Further, by performing A / D conversion on the output signals of the amplifier circuits 11a to 11d, the synchronous detection can be performed by the microcomputer 18.

In the microcomputer 18, calculation is performed every few seconds by a timer interrupt or the like based on the detection signal, the temperature of the infrared source and the heating area are increased, and the appearance of the presence or absence of CO ₂ molecular resonance radiation is accumulated for several minutes. , Based on the data, check whether the temperature and heat generation area are constantly increasing,
If it is increasing, it is judged as a fire, the driver 19 is driven, the relay RLY is turned on, and the alarm device 20 is driven.

For example, in the case of a smoky fire, the outputs of the infrared detectors 3a to 3d change as shown in FIG. That is, the outputs a, b, c, d of the infrared detectors 3a to 3d increase in the order of d, c, b, a as the temperature rises and the spread area increases. And when the flame T
Infrared detector 3a because the resonant emission of CO ₂ molecules increases dramatically at F.
The output of 3c out of ~ 3d increases significantly. After that, since the infrared source becomes a flame, the temperature rise will not nest, and the increase in the infrared ray amount with the increase of the area will be the main factor.
The output of ~ 3d increases respectively, but the output ratio becomes almost constant.

On the other hand, in the case of non-fire, the temperature or area of the infrared source becomes a steady state or extinguished state within a predetermined time. For example, in the case of heating appliances, cooking appliances, etc., the heating area is not increased and the temperature reaches a steady state in a predetermined time.

Therefore, the temperature of the infrared source is obtained by comparing the outputs of the infrared detectors 3a to 3d, and the infrared detector 3a at that temperature is obtained.
It is possible to know the heat generation area by comparing the outputs of 3a, 3b and 3d among 3d to 3d with a preset value. Furthermore, from the infrared source temperature and heat generation area obtained by the above procedure, the blackbody radiation intensity, that is, the case when the heat source is assumed to be a blackbody
Infrared radiation intensity calculated in CO ₂ molecule resonance radiation wavelength band, and its value, by comparing the output of the infrared detector 3c for detecting a resonance radiation wavelength band of CO ₂ molecules, the resonance radiation of CO ₂ molecules You can know the existence.

In this way, if the temperature and heat generation area have a tendency to increase for a certain period (several minutes) or more and the resonance emission of CO ₂ molecules is not observed, it can be determined as a smoldering fire. At a certain point, if the temperature and heat generation area suddenly increase and resonance emission of CO ₂ molecules is observed, it is determined that the smoky fire has shifted to a flaming fire, and for example, the volume of the alarm is turned on. It can be increased or the pitch of the sound can be changed to notify that effect. Furthermore, when the resonance radiation of the CO ₂ molecule is suddenly detected from the state where infrared rays are not detected, and the high-temperature heat generation is detected accordingly, and moreover, the heat generation area thereof is rapidly increased, it can be judged as arson. On the other hand, if no increase in the area of heat generation is seen, it can be determined that the equipment is a flame-handling device (stove, stove).

Since the present invention makes a fire determination based on a very practical fire phenomenon, false alarms can be significantly reduced unlike the prior art. Further, the radiation temperature is calculated during this fire determination routine, and the temperature data is transmitted to the air conditioner 51 to create a comfortable indoor environment.

7 to 9 show an example of the structure and use of a pyroelectric sensor 40 in which four bandpass filters and infrared detectors are housed in one package, and FIG. 10 shows an example of the circuit. Show. Here, four infrared detectors, which are separately provided in the above specific example, are assembled as a single unit. That is, in this package type infrared sensor 40, as shown in FIG. 9, pyroelectric bodies 43a, 43b, 43c, 43d are arranged in each quadrant into which a disc-shaped insulating substrate 41 is divided into four, and the above-mentioned each is placed in front of it. A window 42 consisting of four-division type bandpass filters 42a, 42b, 42c, 42d corresponding to the pyroelectric body is arranged, and the substrate 41 and the window 42 are connected by a seal can 46, and four types of infrared wavelength bands are detected as a whole. It is configured as a package type sensor that can be used. Each of the four-division bandpass filters 42a to 42d has a transmission center wavelength of 2.6 μm.
m, 3.7 μm, 4.3 μm, and 9 μm, and the transmission bandwidth is 0.1 to 1 μm. This four-division filter is manufactured by selectively vapor-depositing a dielectric multilayer film on a single transparent glass substrate four times, or by laminating four fan-shaped band pass filters. Filter 42a
The infrared rays that have passed through -42d are separately detected by the pyroelectric bodies 43a to 43d, and are processed by the signal processing circuit 10 as before. It is desirable to provide a partition wall in the seal can 46 that divides the internal space into four parts according to the filter.

Each of the pyroelectric elements 43a to 43d is composed of two pyroelectric elements S ₁ and S _{2 which} are reverse-polarized, as shown in FIG. 10, and each of the terminals of _one pyroelectric element S ₁ is impedance-converted. For FET4
The gate terminals of 7a, 47b, 47c and 47d are connected. This FE
A positive power supply voltage V _DD is applied to the drain terminals of T47a to 47d, and output signals are taken out from the respective source terminals. The terminal of the other pyroelectric element S ₂ is connected to the ground point E, and the input resistors R ₁ and R ₂ having the same high resistance value are respectively provided between the gate terminals of the EFTs 47a to 47d and the ground point E. , R ₃ , R ₄ are connected.

Although not shown, the FETs 47a to 47d are pyroelectric bodies 43a to 43d.
The input resistors R _{1 to} R ₄ are mounted above the insulating substrate 41, respectively, and are connected to each other by a bonding wire or soldering and enclosed in a seal can 46.

[Effects of the Invention] As described above, the present invention includes a bandpass filter that separates infrared rays emitted from a surveillance space into a plurality of wavelength bands, and an infrared detector that detects the infrared rays that have passed through each bandpass filter. , One of the plurality of wavelength bands includes a resonant radiation wavelength band of CO ₂ molecules, 1 to 1
Signal processing for determining fire occurrence and calculating radiation temperature in the monitoring space based on the output of the infrared detector for detecting the 6 μm wavelength range and the outputs of the infrared detectors in the respective wavelength bands and the temporal change of the ratio of these detection outputs By configuring an environment monitoring device with the device, the air conditioner is controlled by constantly monitoring the radiant temperature for environmental control through the measurement of a common physical quantity called the radiant temperature. Judgment is made by detecting abnormal patterns of radiation temperature and detecting CO ₂ gas resonance absorption infrared rays, and whether the temperature change of the whole environment is due to electric heaters or heating appliances with fire such as gas stoves and stoves. It is possible to accurately judge whether there is a temperature change or a fire, and to control the environment comfortable for the human body and to prevent malfunctions. This has the effect of enabling fire detection.

[Brief description of drawings]

FIG. 1 is a basic configuration diagram showing an embodiment of an environment monitoring device according to the present invention, FIG. 2 is a diagram showing a relationship between an infrared wavelength emitted from an infrared radiation source and an amount (relative value), FIG. (A) is a diagram showing a temperature change at the time of a fire, FIG. 3 (B) is a diagram showing a change of a heat generation area at the time of a fire, and FIG. 4 is a schematic configuration diagram showing an example of an infrared detection device. FIG. 6 is a circuit diagram showing an embodiment of a signal processing circuit, FIG. 6 is a diagram showing an output change of each detector of the fire detection device of FIG. 1 when a fire occurs, and FIG. 7 is a package type infrared detector. Fig. 8 is a perspective view showing an example, Fig. 8 is a schematic configuration diagram of a fire detection device using the same, Fig. 9 is an exploded perspective view showing the internal structure of the infrared detector, and Fig. 10 is a circuit configuration of the infrared detector. It is a circuit diagram which shows an example. 1 ... Chopper, 2a ~ 2d ... Bandpass filter, 3a ~
3d ... infrared detector, 4 ... rotation detector, 20 ... alarm device, 50 ... signal processing device, 51 ... air conditioner, 52 ... temperature measuring device, 53 ... infrared detecting device.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Hideo Segawa Inventor Hideo Segawa 3-17-35, Niizominami, Toda City, Saitama Nihon Mining Co., Ltd. Kashima Construction Co., Ltd. Technical Research Institute (72) Inventor Keiichi Miyamoto 2-191-1 Tobita-cho, Chofu-shi, Tokyo Kashima Construction Co., Ltd. Technical Research Laboratory (56) Reference JP-A-62-69051 (JP, A) JP-A-64-74695 (JP, A) JP-A-64-74696 (JP, A) JP-A-3-59426 (JP, A)

Claims (3)

(57) [Claims] 1. A bandpass filter for separating infrared rays radiated from a surveillance space into a plurality of wavelength bands, a plurality of infrared ray detectors for respectively detecting the infrared rays passing through the respective bandpass filters, and an output of the infrared ray detectors. An environment monitoring device including a signal processing device that performs a fire occurrence determination and a radiation temperature calculation of a monitoring space based on, and shares an infrared detector with the fire occurrence determination and the radiation temperature calculation,
The plurality of bandpass filters include a bandpass filter having a center wavelength of 4 to 5.5 μm and a bandpass filter having a center wavelength of 8 to 15 μm including at least the resonance radiation wavelength band of CO 2 molecules, and the signal processing device includes A heat generation area is calculated based on the output of the infrared detector, and a fire occurs based on the obtained area and the temporal change of the outputs of the infrared detectors and the ratio of the output of the infrared detectors. An environmental monitoring device characterized by making a determination. 2. A bandpass filter having a center wavelength of 2 to 3 μm, a bandpass filter having a center wavelength of 3 to 4 μm, a bandpass filter having a center wavelength of 4 to 5.5 μm, and a center wavelength of 8 to 15 μm. Among the bandpass filters, three or more bandpass filters including a bandpass filter having a center wavelength of at least 4 to 5.5 μm and a bandpass filter having a center wavelength of 8 to 15 μm are provided. The environmental monitoring device according to the first section. 3. A contact type temperature measuring device for measuring indoor air temperature, wherein the signal processing device forms a control signal for an air conditioner or an air conditioner based on outputs of the temperature measuring device and the infrared detector. The environment monitoring device according to claim 1 or 2, wherein: