JPH0317536A - Measuring apparatus of humidity - Google Patents

Abstract

PURPOSE:To make it unnecessary to attach a device having a light source to an object of measurement, to make an apparatus small in size and to save power by measuring infrared rays emitted by a substance itself. CONSTITUTION:All infared rays led by an optical fiber 5 are led out to a humid ity measuring unit 6 through an opening 7 of the measuring unit. The measuring unit 6 is provided with a pyroelectric element 11 and a rotary plate 8, and the rotary plate 8 has band-pass filter lenses 10 for wavelengths to be absorbed by water, and through holes 9, in different numbers. The pyroelectric element 11 receives all infrared rays or near infrared rays alone and turns them into band electric signals. Then the signals are received by A/D 17 and a central processing device 18 through an amplifier circuit 12, a filter circuit 13 and rectifier circuits 15 and 16, and in the device 18, the received signals are com pared with data stored beforehand. Next, a humidity display unit 19 displays humidity in accordance with signals outputted from the device 18 and on the basis of comparison in the quantity of received light between all lights in an infrared band and only the near infrared rays of the wavelengths absorbed by water. According to this constitution, an apparatus can be made small in size and a power can be saved.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a humidity measuring device that can measure humidity using a pyroelectric element without requiring a special light source. be.

[Conventional technology]

Conventionally, the method of measuring the humidity of steam is as follows:
Some devices measure the amount of water in steam by emitting infrared light of a specific wavelength and measuring the amount of transmitted or reflected light received. This is based on the principle of absorption, which is a property of light. In other words, water vapor in a gas exhibits strong absorption characteristics, especially at specific wavelengths in the infrared region, so if you measure the degree of attenuation that light at the absorption wavelength of water vapor undergoes when it passes through a gas, you can determine the amount of water vapor. This means that the humidity can be measured.

Of course, the light is also attenuated by disturbances such as dirt and dust in the gas or dirt on the measurement window glass, so in the above measurement, use the same measurement system to measure light at a wavelength that is not affected by water vapor. , the influence of disturbance is removed by taking the ratio of the intensities of the two wavelengths of light.

[Problem to be solved by the invention]

However, with such a two-wavelength ratio calculation method,
Even when measuring humidity, a light source is required for the measurement, so the size of the measuring device is relatively large, and the power consumption must also be large. Furthermore, in order to measure the humidity in the piping, it is necessary to cut the existing piping, which makes installation cumbersome and difficult.

[Means to solve the problem]

In order to eliminate such drawbacks, the present invention aims to provide a humidity measuring device that does not require a light source and can be easily installed on existing piping.
It is based on the fact that all substances in the pipe emit infrared radiation depending on their temperature. The present invention uses a pyroelectric element and has different numbers of bandpass filter lenses and through holes for wavelengths absorbed by moisture, thereby converting moisture absorption wavelengths and infrared wavelengths into pulse signals having different frequencies. The basic idea is to divide it into

That is, the present invention provides an optical system connecting means attached to a pipe;
A measurement section opening that guides all light in the infrared range to the humidity measurement section through the connection means, a pyroelectric element within the humidity measurement section, and a pyroelectric element arranged on an axis connecting the measurement section opening and the pyroelectric element. The through-holes have a rotating surface that rotates in a plane perpendicular to the axis of the lever, and are provided at equal intervals and in different numbers at positions on a circumferential line whose radius is from the center of rotation of the rotating surface to the axis. and a rotating plate arranged with a filter lens that passes only near-infrared rays of wavelengths that are absorbed by moisture;
A filter circuit A and a filter circuit B that receive all light in the infrared region or only near infrared light with a wavelength that is absorbed by moisture and convert it into a band electric signal using a pyroelectric element, and receive these signals, respectively, and these filter circuits A and B A central processing unit receives a signal from the main unit via each rectifier circuit and compares the received signal with pre-stored data, and according to the signal emitted from the central processing unit, it detects all light and moisture in the infrared range. A certain humidity measuring device is equipped with a humidity display section that displays based on a comparison of the amount of received light of only near-infrared rays of wavelengths that are absorbed by the humidity measuring device.

The energy of the wavelength absorbed by water changes depending on the amount of water in the pipe, so the amount of water can be determined by measuring the amount of light at this wavelength. Additionally, since the energy of all wavelengths in the infrared range changes depending on the temperature inside the pipe, this also makes it possible to measure the temperature at the same time.

[Effects of the Invention] According to the present invention, since the infrared rays emitted by the substance itself are measured, there is no need to attach a device having a light source to the object to be measured, and there is no shape restriction. It also consumes less power.

Furthermore, since it is sufficient to simply make a hole in the existing piping, attachment to the piping is easy.

〔Example〕

The present invention will be explained in detail below based on the drawings.

As shown in FIG. 1, in this embodiment, the piping t
A tube wall opening 2 is provided in the tube side wall in the radial direction, a holding plug 3 is attached to the tube wall opening 2, and an optical fiber connector 4 is detachably inserted into the holding plug 3 to receive infrared rays inside the tube. , and an optical fiber 5 that guides all the light in the infrared range received by the optical fiber connector 4, which serves as a connection means for an optical system. Then, the optical fiber 5
The total infrared rays guided by the humidity measuring section 6 are led out to the humidity measuring section 6 through the measuring section opening 7. In the measuring section 6, a conventional pyroelectric element 1l and a rotary plate 8 driven by a motor are provided. The rotating plate 8 is disposed on an axis connecting the measuring section opening 7 and the pyroelectric element 11, has a rotating surface that rotates in a plane orthogonal to this axis, and has a rotating surface that rotates from the center of rotation of the rotating surface to the axis. At positions on a circumferential line with a radius of up to 4 Jl, through holes 9 provided at equal intervals and in different numbers and filter lenses 10 that pass only near infrared rays of wavelengths absorbed by moisture, for example 1.9 μm, are arranged. are doing. The reason why the number of through holes 9 and the filter lenses 10 are different is that, as described above, the moisture absorption wavelength and the entire infrared wavelength are converted into pulse signals of different frequencies and separated. The entire infrared rays or only the near infrared rays are received and converted into a band electric signal by the pyroelectric element 11, and the signals amplified by the amplifier circuit 12 are received by the filter circuit A13 and the filter circuit B14, respectively. Then, the signals from these filter circuits A, B13, and 14 are converted into respective rectifier circuits l5.
, 16, the A/D 17 and the central processing unit 18 compare this received signal with pre-stored data. According to the signal emitted from the central processing unit 18, the humidity is displayed on the humidity display section 19 based on a comparison of the amount of light received in all of the infrared range and only near-infrared light having a wavelength that is absorbed by moisture. Furthermore, it is also possible to simultaneously display the temperature on the temperature display section 20 based on the amount of light received in all infrared ranges.

The present invention is not limited to the embodiments described above, and it is of course possible to make various changes without departing from the spirit thereof.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing an embodiment of the present invention, and FIG. 2 is a front view of the rotating plate. 4...Optical fiber connector 5, 8, 9, 10, 1l... Optical fiber, rotating plate, through hole, filter lens, pyroelectric element

Claims (1)

[Claims] A connecting means for an optical system attached to the pipe, a measuring section opening (7) that guides all light in the infrared range to the humidity measuring section via the connecting means, and a pyroelectric element (11) in the humidity measuring section. A circumference that has a rotating surface that is arranged on an axis that connects the measurement part aperture and the pyroelectric element and that rotates in a plane perpendicular to this axis, and whose radius is from the center of rotation of the rotating surface to the axis. A rotary plate (8) on which through holes (9) are provided at equal intervals and in different numbers at positions on the line, and a filter lens (10) that passes only near-infrared rays of wavelengths that are absorbed by moisture. , a filter circuit A (13) and a filter circuit B (14) which receive all light in the infrared range or only near infrared light with a wavelength that is absorbed by moisture and convert it into a band electric signal using a pyroelectric element, and receive this signal, respectively. , a central processing unit (18) which receives signals from these filter circuits A and B via their respective rectifier circuits and compares the received signals with pre-stored data; A humidity measuring device characterized by comprising a humidity display unit (20) that displays a display based on a comparison of the amount of light received in all infrared ranges and only near-infrared light at a wavelength that is absorbed by moisture, in accordance with a signal.