JP2003270137A - Optical detection method of wood preservative - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To discriminate and separate wood in which is applied and impregnated with a poisonous CCA preservative from a large quantity of waste wood using an optical detection method. <P>SOLUTION: We found that differences in characteristics of refraction and fluorescence of near infrared light between normal wood and that of wood applied and impregnated with a preservative such that the differences in the characteristics of absorption of a CCA compound between the wavelengths of infrared light from 600 to 1050 nm and those of from 1200 to 1600 nm exist, the differences in the fluorescence intensity at the wavelengths of visible light from 500 to 700 nm exist due to CCA compound venenosity when excited fluorescence is examined by irradiating ultraviolet light having a wavelength of 365 nm, and the differences in the fluorescence intensity at the wavelengths of red light from 580 to 700 nm exist when excited fluorescence is examined by irradiating visible light (blue) having an average wavelength of 470 nm. We also found that X-ray fluorescence of copper at the wavelengths of X-ray can be used to detect CCA. By utilizing the characteristics of light, existence of CCA preservative applied and impregnated to timbers can be detected nondestructively. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a preservative-treated wood detecting method and apparatus for nontoxic and nondestructive detection of toxic metal compounds impregnated or applied to wood.
Efficiently discover antiseptic wood from a large number of waste wood at industrial waste treatment plants, construction demolition sites, etc., and separate waste wood into clean resources and those that are not, to ensure safety during reuse. It is intended to be useful for.

[0002]

2. Description of the Related Art According to 1996 waste statistics, the amount of waste wood generated in Japan is about 47 million m ³ per year.
0% or more is not reused but is incinerated or disposed of by landfill. Most of the causes are timber generated during the dismantling and construction of houses, accounting for about 74% of all waste. Among them, in particular, the waste wood resulting from the dismantling of a house is often the wood impregnated with or applied with a wood preservative for the purpose of preserving and controlling ants.

Types of wood preservatives registered in Japanese Industrial Standard JIS K 1570 include water-soluble preservatives such as chromium / copper / arsenic compounds (CCA), phenols / inorganic fluoride compounds (FCAP), Alkylammonium compounds (AAC), chromium / copper / zinc compounds (CFKZ), copper / alkylammonium compounds (ACQ), copper / boron / azole compounds (CUA)
Z), boron-alkyl ammonium compounds (BAA
C), a fatty acid metal salt-based compound (NCU {copper naphthenate compound}, NZN {zinc naphthenate compound}, VZN {zinc versatic acid compound}), an azole-based compound (AZP), and other oily agents as emulsifying preservatives There is a creosote oil wood preservative as a wood preservative.

Among them, preservative-treated wood (hereinafter referred to as "CCA-treated wood") injected with CCA preservative (chromium / copper / arsenic compound-based wood preservative) is preservative-treated by impregnating and applying toxic heavy metal compounds. It is a representative of wood, and the amount used in the past is overwhelmingly large, which is a major obstacle to promoting the recycling of waste wood.

CCA-treated wood produces toxic gas containing arsenic when it is incinerated and reduced in volume at an industrial waste treatment plant, and incinerated ash contains hexavalent chromium and arsenic which are harmful substances. Become. Further, even if carbonized, the charcoal product contains high concentrations of copper, chromium and arsenic. In addition, arsenic, chromium, and copper may leak from the landfill, causing environmental problems.

The behavior of contained heavy metals is described in Mokuzai Gakkaishi, Vol. 46, No. 6, (2000p587-5
As shown in 95), the behavior of copper, chromium, and arsenic at the time of burning CCA-treated wood is such that chromium contained in wood remains in the incineration ash with a residual rate close to 100%, regardless of the combustion temperature. Copper and arsenic tend to decrease as the combustion temperature rises, and the residual rate is 40% to 80%. Especially, the higher the content of copper, chromium, and arsenic, the lower. This decrease in the residual rate of arsenic is due to thermal evaporation, and it is considered that arsenic gas is released into the atmosphere. It was also confirmed that when carbonized with CCA-treated wood, copper and chromium were less likely to evaporate and remained in charcoal at a high concentration, resulting in evaporation of arsenic. From the above, when recycling CCA-treated wood as a raw material or producing charcoal, it is necessary to take measures against the contained heavy metals.

In addition, according to a survey on chemical substances in waste wood conducted by the Waste Research Foundation, the results of measuring the heavy metal content of CCA-treated wood are shown in Table 1 below, and the average content of heavy metals is Chrome 1053mg / kg, Copper 42
It was 5 mg / kg and arsenic 460 mg / kg. In addition, as a result of performing an elution test from CCA-treated wood, chromium 6.2 to 19.2 mg / L, copper 3.8 to 12.2 mg
/ L, arsenic was confirmed to be eluted at a concentration of 2.8 to 14.6 mg / L. Further, when the CCA-treated wood was landfilled, the elution rate was 5 to 10% of the content of copper, chromium, and arsenic in the powder sample, but it was confirmed that heavy metals could elute. Attention is also paid to the landfill disposal of waste wood because it was eluted at a concentration higher than the judgment criteria (Table 2) in the Environmental Agency Notification No. 13 Act stipulated by law.

[0008]

【table 1】

[0009]

[Table 2]

In the future, considering the rebuilding work of houses and the recent spread of gardening materials, it is easily expected that preservative wood, especially CCA-treated wood, will increase and a large amount will be generated as waste wood. There is a need for the development of an antiseptic wood detection technology that enables non-destructive, non-contact and rapid discrimination of impregnated and applied wood.

[0011] In addition, in order to promote the recycling of waste wood, CC at industrial waste disposal sites and construction demolition sites.
A For wood that has been contaminated with harmful metal compounds, including treated wood, and other waste wood, including all parts that may be infused with harmful substances, separate and separate all of this, and distinguish Proper recycling and disposal is required. Therefore, it is an important issue to quickly identify and separate CCA wood, etc. in a non-destructive, non-contact manner. For automation of use in waste wood receiving business, waste disposal business and construction demolition site, and cost reduction. There is a strong demand for the development of connected detection methods.

At present, the methods for detecting and quantifying harmful heavy metal compounds (CCA preservatives) impregnated and applied to wood components and the like are elemental analysis by atomic absorption spectrometry, absorptiometry and titration. Quantification of compounds by the method is mainly used. As a color reaction by simple application of CCA preservative, a chromium compound is reacted with chromium by a diphenylcarbazide solution, and a color reaction by a reddish purple complex and an atomic absorption method are used to determine that copper ions are diethyldithiocarbamic acid. The yellowish brown complex formed by reacting with sodium is extracted with -N-butyl acetate and the absorbance is measured. Further, there is a method in which arsenic is generated as arsenic hydride and absorbed in a chloroform solution of silver diethyldithiocarbamate to measure the absorbance of the resulting reddish purple solution.

Further, a method for quantitatively analyzing a wood component using an instrument has also been studied, and examples of such methods include NMR (nuclear magnetic resonance) spectroscopy, FTIR (Fourier transform infrared) spectroscopy, and fluorescence spectroscopy. .

However, in NMR spectroscopy, it is necessary to collect a sample in a sample tube, which has the drawback of lengthening the analysis time. In addition, the fingerprint area 650 to 1600 cm-1
Conventional FTIR spectroscopy using the range (6,250-15,300 nm) requires sample preparation, with KBr
There is an annoyance that powders must be mixed and molded.

On the other hand, NIR (near infrared) spectroscopy has the advantage of being simple because it can directly measure a sample,
There is an example of being used for quantification of wood components such as cellulose, lignin, hot water soluble matter and alkali soluble matter. However, until now, NIR spectroscopy has many problems as an analytical method, such as the absorption region of many wood components and the absorption region of water being overlapped, and the absorption bands being broad. There is no example used for evaluation and judgment of wood preservatives. Also N
In spectroscopic analysis including IR, in most cases, changes in light transmission characteristics are measured so as not to depend on the shape and surface state of the sample. However, in order to measure the transmission characteristics, it is necessary to process the inspected wood into a specific shape, and it is difficult to perform nondestructive and noncontact measurement.

Further, in the conventional NIR spectroscopic analysis, necessary information is extracted by dispersing the detection light using a diffraction grating or an AOTF (acoustic optical tunable filter) and analyzing the obtained continuous spectrum. However, since these spectroscopic systems require expensive parts and require precise optical systems, a small, robust, and inexpensive device that can be used at a demolition site or a waste wood receiving site is manufactured. It was difficult.

Further, fluorescence spectroscopy is used as a method capable of nondestructive and noncontact analysis of a sample. In this method, light having a longer wavelength than the excitation light generated by irradiating the sample with the specific excitation light is detected. In fluorescence detection using ultraviolet light or visible light as excitation light, those having a specific structure at the molecular level emit fluorescence. However, since fluorescence due to ultraviolet light or visible light often has a wide line width and is problematic as a general-purpose analyzer, it is mainly used for applied measurement using substances with remarkable fluorescence characteristics in specific fields such as biology, science, and medicine. Is used for.

Further, the fluorescent X-ray method using X-rays having high energy as excitation light excites the electrons of the atomic core inside the substance, so that the atoms constituting the substance can be identified. However, the general fluorescent X-ray method requires an X-ray tube which is dangerous to handle, and further requires a diffraction grating for spectral analysis and a wave height analyzer, resulting in a large-scale apparatus configuration.

Machines are often used to dismantle buildings,
Wood chips are often in the form of mince (mixed waste), such as surface dirt, the effects of heat radiation, air,
The influence of water is great. In such a state, it is very difficult to tell whether the wood has been preservative-treated. Even in the case of manual dismantling, it is difficult to judge whether or not it has been subjected to antiseptic treatment. Therefore, the visual inspection by coloration and the conventional spectroscopic method using large-scale equipment are difficult to identify the harmful waste wood in the disposal site of waste wood or the construction demolition materials, etc. Therefore, it cannot be a practical discriminating means.

[0020]

DISCLOSURE OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art. By using an optical detection method, a toxic metal compound can be produced from a large amount of waste wood. It aims to realize non-destructive and rapid discrimination / separation of impregnated / applied wood, especially wood impregnated / applied with CCA preservative, and to realize automation and cost reduction.

That is, the waste wood resulting from the dismantling of the house is made into chips as recycled resources, and recycled wood boards (wood boards manufactured by crushing construction-generated wood) and recycled wood mulching materials (weed prevention materials and weed prevention materials). Recycled waste wood as a material to protect and promote the growth of plants), compost, carbonization, and the effective use as raw materials for wood fuel, activated carbon, environmental cleaners, soil conditioners, etc. This is where you get lost.

The CCA preservative is a compound of chromium, copper and arsenic, and there are No. 1, No. 2 and No. 3 depending on their mixed distribution. Effectiveness in this case means chromium compound (as CrO3), copper compound (as CuO), arsenic compound (As
2O5) No. 1 is a compound containing 20% or more of chromium compounds and a small amount of arsenic, and there are a salt type produced using salts of chromium and copper and an oxide type produced using oxides. .

This CCA preservative has been used in Japan since about 1964, and about 10 years per year since 1945.
It has been used for 10,000 tons, and its safety has been pointed out since its peak in 1992, and it has been decreasing recently. However, unlike creosote oil that has been used for utility poles and sleepers, CCA-treated wood is water-soluble and colorless and odorless, so it is mainly used for the foundation of houses and construction applications at about 300,000 m ³ / year. . In particular, recently, processed CCA-treated wood has been imported from the United States and Canada, and the amount of CCA-treated wood used for housing, gardening materials, park materials, etc. tends to increase.

The wood referred to herein, which is impregnated and coated with a toxic metal compound, particularly wood which is impregnated and coated with a CCA preservative or the like, is mainly used for the following purposes. Foundation of wooden structures, joists, floorboards, pillars, braces, balconies, terraces, wet edges, wooden fences, wooden utility poles, sleepers, street tree stanchions, garden tree stanchions, luggage transport container panels, civil engineering foundation piles, Wood bridges, wooden log products, park snails, vents, gardening materials, etc.

The CCA preservative that is injected into CCA-treated wood forms a compound that is sparingly soluble in water in the wood after it is injected into the wood, and is fixed to the wood as an organometallic compound. The reaction formula is as follows in CCA-1. 2CuSO4 + 4K2Cr2O7 + 5AS2O5 ・ 2H2
O → 8CrAsO4 + 4CuHAsO4 + 2K2SO4 + 4
KOH + 7H2O + 12O ↑ However, this chemical reaction has a fixing time of 3 weeks because of the relationship between the temperature after injection, the species of wood, the speed of drying, and the amount absorbed, but its behavior is unclear because it changes depending on the factory and time management. .

According to an experiment on chemical substances from waste wood conducted by the Waste Research Foundation, the result of measuring the heavy metal content of CCA-treated wood (Table 1) showed that the average content of heavy metals was 1053 mg / kg of chromium and copper. 425 mg / kg, arsenic 460
Reported as mg / kg.

That is, the CCA preservative is a compound of a wood component (cellulose, hemicellulose, lignin, etc.) and a metal salt, and the organic compound has a chemical structure containing a metal. Generally, these liquid organometallic compounds are more stable compounds as they contain a large amount of heavy metals, and the organometallic compounds are extremely toxic and are characterized by methylmercury, organotin compounds and CCA preservatives. , Diethyl zinc, and the like. Its chemical structural form is
It can be divided into the following three types. (1) Ionic bond compound: metal salt of acid or alcohol (2) Covalent bond compound: a compound in which a carbon atom and a metal have an A bond, which is an organometallic compound. (3) Coordination-bonding compound: a complex metal in which a molecule or anion is coordinated with a metal. Chromium / copper / arsenic compounds (CCA), phenols / inorganic fluoride compounds (FCAP), alkyl ammonium compounds (AA) used as wood preservatives
C), chromium / copper / zinc compound (CFKZ), copper / alkylammonium compound (ACQ), copper / boron /
Azole compounds (CUAZ), boron-alkylammonium compounds (BAAC), fatty acid metal salt compounds (NCU {copper naphthenate compounds} NZN {zinc naphthenate compounds} VZN {zinc versatate compounds}), azoles Water-soluble preservatives such as compounds (AZP) are complex combinations of the ionic bond, covalent bond, and coordinate bond described above. The ionic bond compound is highly soluble in water and highly reactive. Has a low response and is stable. The organometallic compound is represented by an alkyl group by a covalent bond, and the complex metal is often a double or triple bond. In many cases, the organometallic compound and the complex metal are difficult to distinguish clearly.

Usually, the infrared absorption spectrum (infrar)
ed absorption spectrum; IR
Is abbreviated), and the infrared light emitted from the light source is applied to the sample, and the infrared light absorbed by the sample is represented by a curve drawn by wavelength and absorbance. These infrared absorption spectra are peculiar to the features of the chemical structure of the molecule of the organic compound, and various information about the molecular structure, electronic state, functional groups, etc. can be obtained, so confirmation of the structure, qualitative analysis, quantitative analysis, etc. Used for.

However, since the infrared absorption spectrum of CCA-treated wood impregnated and coated with CCA preservative is a substance due to a complicated chemical reaction of a metal compound and overlaps in a complicated and wide range, CCA is coated and impregnated. Conventional IR is not suitable for the analysis of multi-component mixtures such as wood.
Furthermore, in the fingerprint region of the infrared absorption spectrum, the influence of heat radiation from the sample and the influence of air and moisture are large, and measurement without contact is extremely difficult.

On the other hand, near-infrared light is light between visible light and mid-infrared light (wavelength: 800 nm to 2500 nm),
Absorption peaks attributed to functional group overtones are also observed, and the absorption line width is wide and the spectrum changes due to various factors. Therefore, it has hardly been used to identify chemical structures. It is a light area.

However, since the near-infrared light has a property close to that of visible light, it can be observed from a distance as in a visible light camera, and the influence of moisture absorption and heat radiation is small. Therefore, effective use of this band is considered important for non-destructive and non-contact measurement.

In the fluorescence method, it is necessary to determine the optimum excitation light for detecting the change in the fluorescence characteristics depending on the presence or absence of the preservative treatment on the inspected wood. Further, it is necessary to select a wavelength band for observing a change in fluorescence property, to quantify the wavelength band, and further to amplify the change in fluorescence property to a level that can be used for determining the presence or absence of a preservative. Another important issue that must be solved is to use a detection method that is inexpensive, safe, and has a robust device configuration.

For non-destructive non-contact measurement, a spectroscopic analysis method using reflected light and a fluorescence detection method are promising means, but the reflected light is the surface condition of the sample (surface roughness, reflection angle,
Since it depends greatly on dirt, moisture, etc., it is necessary to develop a method that is not affected by these effects.

[0034]

Means for Solving the Problems The present invention has been earnestly studied as a technical problem of a method for judging the presence or absence of a preservative contained in the above preservative-treated wood, especially CCA-treated wood, and as a result, the wood preservative has been impregnated. -It was found that the applied wood has a difference in visible light and near-infrared light reflection characteristics and fluorescence characteristics from ordinary wood, and it relates to a wood preservative detection method using the characteristics.

In the experiment according to the present invention, CCA-treated wood was irradiated with visible light or infrared light having a plurality of wavelengths on the sample, and the reflected light was detected.
It was found that the absorption characteristics of the CCA compound became remarkable at 1050 nm, and the difference in absorption due to the presence or absence of the CCA compound was small at 1200 to 1600 nm. It was also confirmed that near-infrared light has a longer wavelength than visible light and therefore has high transmission characteristics and is resistant to dirt on the surface of the inspected wood. If the inspected wood is wet, there is a water absorption peak 14
It was feared that absorption around 50 NM would increase and be affected, but conversely, it was also confirmed that the influence of water could be reduced by avoiding this band.

These characteristics are almost independent of the tree species used as the raw material of the wood to be inspected, and it is clear from the measurement using coniferous and hardwood-containing rice pine, red pine, cedar, spruce, hemlock, zelkova, walnut, and oak. became. In addition, although there is a difference in the short wavelength range of visible light (blue, green) between the core material and the sapwood,
It has been confirmed that there is almost no difference in the near infrared region and that it does not cause a disturbance.

The center wavelength of the CCA-treated wood is 365
As a result of detecting excited fluorescence by irradiating ultraviolet light of nm, the fluorescence intensity of visible light at 500 to 700 nm is C
Differences were found with and without the CA compound. Further, a similar difference was found in the fluorescence intensity of 580 to 700 nm (red) excited by irradiating visible light (blue) having a center wavelength of 470 nm from the light emitting diode. C in either case
The presence of the CA compound significantly reduces the fluorescence intensity. However, in the case of ultraviolet light excitation, it has been confirmed that the change in fluorescence intensity decreases when the surface of the sample is wet or dirty.

Further, an X-ray tube of a tungsten target, to which a direct current voltage of 45 kV was applied, was applied to CCA-treated wood.
Upon irradiation with a ray, it was confirmed that X-rays due to diffusion and fluorescence were emitted in the direction of about 45 ° with respect to the irradiation direction. As a result of spectral analysis of this X-ray, wavelength peaks of reflected X-rays were detected near 1.54Å and 0.6Å. Furthermore, when wood that does not contain CCA was measured in the same manner, it was 1.54 Å
It disappeared, and it was confirmed that this peak was unique to CCA. This peak was identified as the copper Kα line.

Since it has been known in advance that CCA-treated wood contains copper, chromium and arsenic, if one of them is significantly larger than that of untreated wood, it can be judged as a CCA-treating agent. Therefore, in the fluorescent X-ray detection, it is not always necessary to disperse the X-rays obtained as fluorescence as a spectrum, and a band selection filter using a fixed diffraction grating or a wave height selection filter for selecting a specific energy band from a proportional counter. The wavelength band can be selected by using, and the fluorescent X-ray of copper, chromium, or arsenic can be detected.

Further, in this system, it is not necessary to apply a high voltage in order to emit X-rays of a short wavelength from the X-ray tube,
Further, the diameter of the X-ray generation part may be large. Further, since it is not necessary to transmit the inspected wood, it is not necessary to increase the X-ray power. This greatly reduces the load on the X-ray tube, prolongs the life of the device, eliminates the need for a cooling unit, and is expected to contribute to the downsizing, cost reduction, and robustness of the device. Further, since the fluorescence intensity in the wavelength band can be continuously detected by using the proportional counter, dead time for spectroscopy due to rotation of the diffraction grating does not occur.

Further, in order to support the reliability of the results of these optical detection experiments, in the present invention, the determination based on the infrared absorption spectrum and the intensity ratio of fluorescence and the color reaction are used for the determination of the wood preservative.
Judgment was made by using chemical methods such as nuclear magnetic resonance and elemental analysis.

From these experiments, according to the method of the present invention, CC
It became clear that the presence or absence of the A preservative can be significantly determined.

When the wood preservative penetrates only into the wood, it may be impossible to distinguish it from the surface by light rays. However, preservative-treated wood such as CCA-treated wood is not possible. After processing the wood into the used state, it will be processed by pressure injection and application from the wood surface,
The injected wood preservative formed compounds along the wood grain centering on the surface of the wood and settled, and no sample was found where the preservative was missing only on the surface.

According to the present invention, as described above, the wood impregnated and coated with the wood preservative has a difference in reflection characteristics and fluorescence in a specific wavelength band of visible light and near-infrared light from that of ordinary wood. It was found that the characteristics were effectively utilized.

The present invention utilizes this property of light to determine the presence or absence of a wood preservative (CCA compound or the like) impregnated in or applied to wood from the characteristics of reflected light or fluorescence in a specific wavelength band. This is a method for detecting wood preservatives.

[0046]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a method of using the present invention will be specifically described, but the scope of the present invention is not limited to the examples described below. An apparatus configuration in the wood preservative detection method provided by the present invention will be described with reference to FIG. This detection method irradiates the inspected wood 4 with light including a plurality of wavelength bands by using the illuminating device 1, and reflects light from the inspected wood 4 with a plurality of optical sensors 2 equipped with filters 3 and 3'having different characteristics. 2 ′, measure the reflected light intensity in each wavelength band, calculate those values by the calculation device 5, and compare the result with a preset threshold value corresponding to the presence or absence of a preservative. Then, the determination result is output to the output device 6.

Any illuminating device 1 may be used, but it can be said that the incandescent lamp is suitable because it can emit light in a wide band including near infrared light and is inexpensive. Among them, halogen lamps have a long life and can be suitably used.
In addition to this, arc discharge tubes such as xenon lamps and metal halide lamps, and light-emitting diodes that have undergone remarkable technological innovation can also be used as appropriate. Further, a cold cathode discharge tube is suitable as an ultraviolet light illuminating device for exciting fluorescence, and an LED is suitable for blue illumination. Good results can be obtained by attaching a long-wavelength cut filter to these light sources so that they do not emit light in the fluorescence wavelength band to be detected.

An X-ray tube is suitable as the X-ray light source. The X-ray tube can obtain strong radiation in a specific wavelength band by selecting a target material. In the present invention, it is possible to excite with an X-ray having a relatively long wavelength, and it is not necessary to raise the applied voltage so much. Further, since it is sufficient to irradiate the sample with X-rays over a wide range, the microfocus characteristic and the collimator are not required.

The optical sensor 2 is preferably an element using silicon on the short wavelength side of visible light and near infrared. In the near infrared region, an element using InGaAs or Ge can be used, and any of these materials is known to those skilled in the art and can be appropriately selected. By arranging these elements one-dimensionally, it is possible to determine the position of the inspection object in one direction. Also,
In a device (camera) in which the devices are arranged in a two-dimensional manner, two-dimensional position information is specified, and from the shape information obtained from this information, a lot of effective information such as the area and inclination of the sample can be obtained. In addition to this, an image pickup tube is given as a sensor that can obtain two-dimensional information, and an infrared vidicon is preferably used particularly in the near infrared region.

Further, in X-ray detection, a semiconductor detector (SSD),
A scintillation counter, a proportional counter, etc. can be used. In particular, the proportional detection tube is suitable for carrying out the present invention because it can measure X-ray intensity and wavelength at the same time by using it together with a wave height analyzer and does not require cooling.

Examples of the filter 3 include a filter (colored glass filter) that uses a specific wavelength band absorption characteristic of a substance, a metal interference filter that uses interference, and a dielectric interference filter.
The interference filter can realize various wavelength transmission characteristics, though it has a drawback that the characteristics change depending on the incident angle of a light beam. In particular, the dielectric interference filter has a small insertion loss and has a high degree of freedom in design in the visible light and near-infrared light regions, and is suitable for implementing the present invention. In addition, it is expected that the design of the entire optical system can be made compact by using a mirror with a filter that simultaneously changes the optical path and selects the wavelength band. For X-rays, it is possible to select a wavelength band using a filter that uses diffraction such as the (002) plane of graphite crystal, a metal foil filter that strongly absorbs a specific wavelength, and a wave height analyzer.

The calculation device 5 has a function of calculating the reflected light intensity of each wavelength band obtained from a plurality of photosensors and comparing it with a threshold value.
An analog calculator or the like can be appropriately used.

The output device 6 notifies the information on the presence or absence of the wood preservative obtained by the calculation device to a human or a subsequent antiseptic wood removing machine, and a display monitor, a lamp, a buzzer, a relay contact output, etc. are appropriately used. It is possible.

An incandescent lamp of 500 W (Toshiba photo reflector) is used as an illuminating device, and 900 nm to 1200 n
A sample containing CCA-treated wood and untreated wood is irradiated with light containing abundant wavelength band of m, and visible light to near infrared light (400 to
A camera (Hamamatsu Photonics Co., Ltd., C2741-03) having a sensitivity to 1800 nm has a filter that transmits a wavelength band of 860 to 940 nm and two types of filters that transmit 1143 to 1253 NM (Nippon Vacuum Optical Co., Ltd., DI
F-BPF-3) was attached and a reflection image was taken. The density Aij of each pixel in the 860 to 940 nm band and the intensity Bij of each pixel in the 1143 to 1253 nm band of the two obtained reflection images were calculated by the following equation. Rij = Th-Aij / Bij (1) Here, Th is a threshold value determined using a standard sample so that the CCA-treated material and the untreated material can be separated. A personal computer is used for the calculation, and the NTSC standard analog video signal output from the camera is converted into a digital image using an image capture / processing board (Hitachi Yonezawa Electronics Co., Ltd., VP810) connected to the PIC bus, and RIJ at each pixel is calculated. I asked.

When the calculation result Rij is positive, white is assigned, and when it is negative, black is assigned to each pixel.
It was possible to selectively capture only the part where there was. When fluorescence was excited using an ultraviolet lamp (Toshiba Lightec Co., Ltd., Neoball 5) as a lighting device, it was observed that the fluorescence intensity of CCA-treated wood was reduced by 5 to 20% as compared with untreated wood. Furthermore, as a result of observing various tree species in the visible light to near-infrared region and CCA-treated materials using a spectrometer (Soma Optical Co., Ltd., S-2600 and S-2700) capable of measuring reflection characteristics, 600 in CCA-treated wood. ~ 1050nm
A decrease in reflectance of 5 to 15% was observed in Table 1, and data supporting the results of the Examples are obtained.

For fluorescent X-rays, a metal film thickness meter (Seiko Denshi Co., Ltd., SFT7200) was used, and CCA-treated wood was irradiated with X-rays from an X-ray tube of a tungsten target to which a direct current voltage of 45 kV was applied. Furthermore, the waveband around 1.54Å was selectively detected by the wave height analyzer from the detection signal obtained from the proportional counter installed at about 45 ° from the X-ray irradiation direction. As a result, fluorescent X-ray generation from 1.54Å copper was found to be significant in the CCA-treated wood, and it was possible to distinguish it from untreated wood.

From this, it is possible to identify the presence of CCA by using the present invention, and it is possible to obtain information such as the position and size of the CCA by arranging the sensors in one or two dimensions. it is obvious.

The wood preservative detection method provided by the present invention is achieved by the process shown in the flow chart of FIG.

[Brief description of drawings]

FIG. 1 is a device configuration diagram of a detection method of the present invention.

FIG. 2 is a flowchart of the present invention.

[Explanation of symbols]

1 Lighting device 2, 2'sensor 3,3 'filter 4 Inspected wood 5 arithmetic unit 6 Output device

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G06T 7/60 150 G06T 7/60 150B 150P 150S (72) Inventor Norio Ando Yamagata Ichimoto 3-chome 11 No. 37 (72) Masao Kobayashi 106, Yoshida, Kakita-cho, Nishimurayama-gun, Yamagata Prefecture (72) Inventor Toshiyuki Sato No. 13-65, Josaimachi, Yamagata City, Yamagata Prefecture F-term (reference) 2G001 AA01 BA04 CA01 DA01 DA02 EA03 GA01 GA13 KA01 LA20 2G043 AA03 BA01 BA05 BA14 CA05 EA01 FA01 FA07 GA25 GB28 HA02 JA02 JA03 KA02 KA03 KA05 LA03 NA01 NA05 2G059 AA05 BB08 EE02 EE07 EE12 PF08 BB08 BB08A01 BB08 BB01 BB08 BB01 BB08 BB01 BB08 BB08 BB01 DB02 DC08 DC09 5L096 BA03 CA02 FA15 FA67 FA69 JA11

Claims (5)

[Claims] 1. An optical filter for irradiating light to be inspected with light from a lighting device capable of irradiating light (visible light or near-infrared light) having a plurality of wavelength bands and transmitting reflected light in different wavelength bands. Captured with multiple photosensors, one-dimensional photosensor array or two-dimensional photosensor array (camera) equipped, measure the reflected light intensity in multiple wavelength bands, calculate those intensities with a calculation device, and compare with the threshold value. An optical wood preservative detection method that makes it possible to determine the presence or absence of impregnation or application of a toxic wood preservative (CCA) containing copper, chromium, and arsenic on the inspected wood. 2. The inspected wood is irradiated with light (X-rays, ultraviolet light or visible light) having a plurality of wavelength bands by an illumination device, and the fluorescence and the reflected light are excited from the excited fluorescence and the reflected light by a plurality of filters. Select and measure fluorescence and reflected light intensities with multiple sensors or one-dimensional sensor array or two-dimensional sensor array (camera) respectively, calculate those intensities with a calculation device, and compare with the threshold value. Toxic wood preservative (CCA) containing copper, chromium and arsenic
A method for detecting wood preservatives, which can judge the presence or absence of impregnation or application of wood. 3. An incandescent lamp is used to irradiate wood with white light including visible light and near-infrared light, and a plurality of optical bandpass filters are used to select a wavelength band of reflected light.
Dimensional optical sensor array or camera, measure the reflected light intensity in each wavelength band, calculate the intensity ratio of them using a computer, by comparing the intensity ratio with a threshold, copper, chromium to the inspected wood, The optical wood according to claim 1, wherein presence / absence of impregnation or application of toxic wood preservative (CCA) containing arsenic is determined non-destructively / non-contact, and the determination result can be displayed on a screen or output a warning sound or relay contact output. Preservative detection device. 4. A wavelength range from 600 to 1050n, which has a large absorption of CCA.
Wavelength up to m and absorption of CCA is small 1200 ~ 1600nm
The optical wood preservative detection method according to claim 1 or 3, wherein the presence or absence of the impregnated / coated CCA can be determined by comparing the difference or ratio of the reflected light intensities between the wavelength bands of 1) with a threshold value. 5. The image of each wavelength band is acquired from a plurality of cameras equipped with optical filters having different transmission band characteristics for capturing a plurality of wavelength band images, and the image of the distribution of the wood preservative is obtained by image calculation. The optical wood preservative detection method according to claim 1, wherein the information on the position, shape, inclination, size, and surface state of the preservative-treated wood can be extracted and converted.