JPH0424524A - Remote temperature measuring apparatus - Google Patents

Abstract

PURPOSE:To make it possible to perform accurate temperature measurement even at a shallow depression angle even under sunlight by providing an optical means for introducing external light, and providing an infrared-ray sensor for receiving the emitted light from the optical means. CONSTITUTION:A scanning part condenses external light with a mirror and a lens, and an object is optically scanned. An infrared-ray sensor 4 receives the emitted light from the scanning part 3 and responds to light in the ozone absorbing band in the spectrum of sunlight, i.e. the wavelength band of 9.6mum. The scanning part having the sensitivity in the wavelength in the vicinity of 8 - 13mum is used. A bandpass filter 5 is located between the scanning part 3 and the infrared-ray sensor 4 and transmits light in the wavelength band of the ozone absorbing band of 9.6mum. A cooler 6 cools the infrared-ray sensor 4. A processing part 2 comprises an amplifier 7 for amplifying the detected signal from the sensor 4, an operating part 8 for operating the output of the amplifier 7, a display part 9 for displaying the result, a control part 10 for controlling the operating part 8 and other circuit parts and a scanning driving circuit 11 for driving the scanning part 3 based on the instruction from the control part 10.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a remote temperature measurement device suitable for detecting the temperature of an object under sunlight, such as sea surface temperature.

<Prior Art> As a measuring device for remotely detecting the temperature of an object, there is one that measures the temperature of an object by using an infrared sensor to detect the intensity of infrared rays emitted from the object.

This remote temperature measurement device uses optical means such as lenses and mirrors to guide external light onto the infrared sensor.
By processing the detection signal of the infrared sensor, a temperature measurement of the object can be obtained.

<Problems to be Solved by the Invention> However, when measuring the temperature of an object under sunlight, such as the temperature of sea water, using a conventional remote temperature measurement device, there are the following problems. .

In other words, when measuring under sunlight, the object is generally far away, the temperature measurement device is located relatively low, and the angle (depression angle) between the detection direction of the temperature measurement device and the horizontal direction is small.
However, when the angle of depression in the detection direction is shallow, a large amount of reflected sunlight enters the temperature measuring device in addition to the emitted light from the object, and this reflected light causes The intensity of the synchrotron radiation becomes undetectable, making temperature measurement impossible.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a remote temperature measurement device that can accurately measure the temperature of seawater, etc., even under sunlight with a shallow angle of depression. Take it as a challenge.

Means for Solving the Problems> In order to achieve the above problems, the present invention provides a remote temperature measuring device comprising an optical means for introducing external light and an infrared sensor for receiving light emitted from the optical means. A bandpass filter is provided on the optical path between the optical means and the infrared sensor, and the bandpass filter transmits light in the same wavelength band as the ozone absorption band in the sunlight spectrum, The infrared sensor was configured to have sensitivity in a band including the ozone absorption band.

<Operation> When the remote temperature measuring device having the above configuration is directed toward an object from a relatively low position under sunlight, reflected light of the sunlight enters the optical means from the object together with emitted light. Of these incident lights, only the light in the same wavelength band as the ozone absorption band passes through the bandpass filter and reaches the infrared sensor.
Light outside the ozone absorption band is cut off.

The spectrum of sunlight reflected light does not originally include light in the ozone absorption band, so what is cut by the pantone filter is all of the sunlight reflected light, which has the same wavelength as the ozone absorption band. Only the emitted light from the target object will pass through the bandpass filter.

The infrared sensor receives radiation in the same wavelength band as this ozone absorption band, and a temperature measurement value of the object can be obtained from the intensity of this radiation.

<Example> Hereinafter, the present invention will be described in detail based on an example shown in the drawings.

FIG. 1 is a block diagram of an embodiment of the present invention. The remote temperature measuring device of this embodiment consists of an optical system 1 and a signal processing system 2.

The optical system 1 includes a scanning section 3, an infrared sensor 4,
It includes a bandpass filter 5 and a cooler 6.

The scanning unit 3 condenses external light with a mirror or lens and optically scans the object.

The infrared sensor 4 receives the light emitted from the scanning unit 3, and is sensitive to light in the ozone absorption band in the sunlight spectrum, that is, in the 96 μm wavelength band.
A sensor with sensitivity around m is used.

The bandpass filter 5 is located on the optical path between the scanning unit 3 and the infrared sensor 4 and has an ozone absorption band of 9
, which transmits light in the 6 μm wavelength band. A dielectric multilayer filter is mainly used as the bandpass filter 5, but a diffraction grating may also be used.

The cooler 6 cools the infrared sensor 4.

The signal processing system 2 includes an amplifier 7 that amplifies the detection signal of the infrared sensor 4, a calculation unit 8 that calculates the temperature measurement value of the object based on the output of the amplifier 7, and a display 9 that displays the calculation result. It consists of a control section IO that controls the calculation section 8 and other circuit sections, and a scanning drive circuit 11 that drives the scanning section 3 based on instructions from the control section 10.

In the above configuration, the emitted light of the object from the object,
When reflected light from sunlight enters the scanning unit 3, all of the reflected light enters the bandpass filter 5.

This bandpass filter 5 transmits only light in the same wavelength band as the ozone absorption band.

By the way, as shown in the spectrum diagram in Figure 2, if the sunlight spectrum on the sun's surface is A, this spectrum A is continuous over the entire area, but sunlight on the ground passes through the atmosphere. So, light of a specific wavelength is absorbed and attenuated, and there are several windows in the spectrum B. In the infrared region, the 96 μm wavelength band is the ozone absorption band B due to absorption by ozone. It closes to form a window. The presence of such a window (ozone absorption band B) in the spectrum is the same for reflected sunlight.

Bandpass filter 5 has ozone absorption band B. However, as mentioned above, reflected sunlight is originally in the ozone absorption band B. Therefore, the bandpass filter 5 ends up cutting off all of the reflected sunlight, and only the ozone absorption band B passes through the bandpass filter 5. Only the synchrotron radiation in the same wavelength band as .

The infrared sensor 4 has an ozone absorption band B. It receives radiation in the same wavelength band and outputs a detection signal corresponding to the intensity of the radiation. A detection signal from the infrared sensor 4 is amplified by an amplifier 7 and input to a calculation section 8 .

The calculation unit 8 performs a predetermined calculation based on the amplified detection signal to calculate a temperature measurement value. The temperature measurement value is displayed on the display 9.

<Effects of the Invention> As described above, according to the present invention, only the radiated infrared rays of the object are detected, excluding the reflected light of sunlight. Temperature measurement can be performed without any problem in any situation, and therefore, temperature measurement can be performed accurately even under sunlight with a shallow depression angle.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an embodiment of the present invention, and FIG. 2 is a spectral diagram for explaining the operation. 3...scanning section, 4 infrared sensor, 5 band pass filter.

Claims (1)

[Claims] (1) A remote temperature measuring device comprising an optical means for introducing external light and an infrared sensor for receiving the light emitted from the optical means, and a bandpass filter is provided on the optical path between the optical means and the infrared sensor. is provided, the bandpass filter is one that transmits light in the same wavelength band as the ozone absorption band in the sunlight spectrum, and the infrared sensor is sensitive in the band that includes the ozone absorption band. A remote temperature measuring device characterized by: