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Experiences with the OECD guideline proposals for the estimation of emissions from preservative-treated wood in the environment
2004 - IRG/WP 04-50209
The practicability of 2 CEN proposals for OECD guidelines on the estimation of emissions from preservative treated wood by laboratory methods for either wood held in storage after treatment and for wooden commodities that are not covered, and are not in contact with ground (guideline 1) or wooden commodities that are not covered and are in contact with ground, fresh water or seawater (guideline 2) was tested during a research project in Germany. The influence of several test parameters was investigated for different types of preservatives, i.e. duration of the dipping time for guideline 1 experiments as well as size and surface structure of the specimens, comparability with EN 84 experiments and the influence of the ratio of the water volume per emitting surface area in guideline 2 experiments. Parallel tests in two laboratories allow the assessment of the repeatability of the laboratory tests. The results of the experiments with a solvent based preservative containing propiconazole are presented and compared with experiences from field experiments. The emissions were lower if less water was available per surface area and time. Different specimens yielded similar losses per surface area and the results from leaching experiments according to EN 84 were similar to the results from guideline 2 experiments. Emission rates and total losses can be estimated according to the calculation model of the OECD ESD for Wood Preservatives. Calculated data fit the experimental data. Emission rates of propiconazole estimated in guideline 2 experiments were generally higher than losses by natural rain. Minimum emission rates in these experiments were similar to the maximum values estimated in the field experiment. Losses by guideline 1 experi¬ments were in the range of the field data.
U Schoknecht, R Wegner, E Melcher

Detection of feeding behaviour of termites using AE monitoring
1991 - IRG/WP 1514
Using acoustic emission (AE) monitoring, the feeding activity of the termite inhabiting a wood specimen was investigated. The amplitude and the rate of AE from the specimen of Coptotermes formosanus Shiraki was larger than that of Reticulitermes speratus Kolbe. The AE event rate was higher in the specimen with soldiers than without soldiers. The AE event rate decreased according to the resistance of wood specimens against termite attack.
Y Imamura, M Tokoro, M Owada, Y Fujii, M Noguchi

Leaching of the new boron based biocide from coated wood
2001 - IRG/WP 01-30267
We investigated leachability of the new boron based biocide - a complex of an amine and boric acid - from vacuum impregnated spruce wood samples. It was determined by the standard ENV 1250-2 procedure that the new biocide is susceptible to leaching so from the water borne as well as from the ethanol borne boron containing preservative treated wood. Leaching may be retarded by application of surface coatings. The ability of a surface finish to prevent leaching is correlated to its water vapour permeability.
M Petric, M Pavlic, F Cadez

Modélisation sur maquette du rejet accidentel d'un gaz toxique et inflammable dans l'atmosphere - Emission de type "bouffée d'oxyde d'éthyléne [Water model simulation of toxic and flammable gases in the environment on industrial sites - Puff of ethylen oxide]
1990 - IRG/WP 3576
M Milhe

Rates of emission from CCA-treated wood in the marine environment: measurement, modelling and requirements for further research
2001 - IRG/WP 01-50166-12
Accurate estimates of rates of emission of leachate from preservative treated wood are crucial for realistic predictions of the environmental impact of its use in maritime construction. Estimates are available for some commonly used preservatives, but these vary widely. Though variable, these measurements suggest that emission generally decreases exponentially with time. Part of the variation is due to differences in methodology employed. Physical and chemical characteristics of the seawater used (e.g. temperature, salinity, pH and oxygen content) affect emission rate. So too do the specifics of the treatment process especially the preservative formulation used, and pre- and post-treatment handling of the wood. The nature of the treated wood samples is also important, with misleadingly high estimates being obtained from samples with unrepresentatively high proportions of cross-cut surfaces. A suggested strategy for developing an informative and standardised methodology is discussed. To form useful models of impacts of leaching, emission rates need to be considered in conjunction with site-specific information regarding a) water exchange rates between the area where leaching occurs and the sea, and b) the extent of partitioning of leachate between the water column, biota and sediment. The risk of environmental impact may be reduced by modification to treatment procedures and by careful planning of installation.
S M Cragg, C J Brown, R A Albuquerque, R A Eaton

The identification and preservative tolerance of species aggregates of Trichoderma isolated from freshly felled timber
1992 - IRG/WP 92-1553
The surface disfigurement of antisapstain treated timber by preservative-tolerant fungi remains a major problem in stored timber. Identification of a range of isolates of Trichoderma based on microscopic morphological characteristics was found to be imprecise due to the variable nature of this organism. In addition, studies to compare visual (morphological) characteristics of these isolates with their tolerance to the antisapstain compound methylene-bis-thiocyanate (MBT) using minimum inhibition concentration (MIC) tests showed no clear correlations. Isoenzyme electrophoresis was used to investigate the taxonomic relationships between species aggregates of Trichoderma isolated from antisapstain field trials and to identify physiological differences between 30 isolates of Trichoderma which show tolerance to MBT at concentrations ranging from less than 4 ppm to 34 ppm. Results indicate that there is considerable variability in the preservative tolerance of different Trichoderma isolates from particular locality. This highlights the need for field testing of an antisapstain compound in the same locality and under the same conditions in which it will be used in practice.
R J Wallace, R A Eaton, M A Carter, G R Williams

Detoxification of preservatives: Tri-n-butyltin oxide as a biocide
1982 - IRG/WP 1156
T E Dudley-Brendell, D J Dickinson

A review of environmental emissions from building and construction materials in comparison with preserved wood
2005 - IRG/WP 05-50224-11
A review of the public domain literature concerning emissions to the environment from materials which are used in the construction of buildings (e.g. Concrete, Asphalt, Galvanised Steel), in comparison with preserved wood, and a review of the approaches taken by the construction sector in assessing the risk from environmental emissions, in comparison with the approaches taken by the wood preservation sector.
E F Baines

Biocide Treatments for Wood Composites - A Review
2006 - IRG/WP 06-40323
This paper reviews the biocidal treatment of wood composites. Included are in-process and post-process treatments. Various biocides are covered as are methods of application. Novel treatments and technologies are also presented.
J W Kirkpatrick, H M Barnes

Methane emission by termites, Coptotermes formosanus Shiraki
1995 - IRG/WP 95-10099
Association of methanogenic bacteria only with the smallest-sized symbiotic protozoa Spirotrichonympha leidyi Koidzumi was evidenced by epifluorescence microscopic observations. Workers, which were collected from a laboratory colony and placed in a test container with water supply emitted methane at a relatively constant rate with a peak of 0.76 nmol/termite/hr within the first 72 hrs after the initiation of measurement. Soldiers, as expected, produced less methane with a maximum rate of 0.019 nmol/termite/hr. Although methane formation is considered important to termites in order to keep physiological balance, that undesirably contributes to global warming.
K Tsunoda, W Ohmura, M Tokoro, T Yoshimura

Measurement of VOC emissions from curative treated wood: A new emission test chamber
2001 - IRG/WP 01-50166-13
A poor indoor air quality (IAQ) is now recognized as a potential factor affecting occupants health. There are three basic strategies to improve IAQ: source control, improvement of the ventilation and use of air cleaners. Usually, the most efficient way to improve IAQ is to eliminate the different pollutant sources or to reduce their emissions. In order to precisely measure emissions from building products and estimate the potential heath impact of emitted pollutants, standardised analytical methods are needed. The aim of this paper is to present the new standards prepared by the European Committee for Standardization (CEN) and the International Organization for Standardization (ISO) for the measurement of indoor air pollutants and their application to the characterization of emissions from wood products. The prestandard ENV 13419, subdivided in three parts, has been prepared by the CEN technical committee 264 : ??ENV 13419-1 : Building products - Determination of the emission of volatile organic compounds - Part 1 : Emission test chamber method, ??ENV 13419-2 : Building products - Determination of the emission of volatile organic compounds - Part 2 : Emission test cell method, ??ENV 13419-3 : Building products - Determination of the emission of volatile organic compounds - Part 3 : Procedure for sampling, storage of samples and preparation of test specimens. The two first parts of the prestandard ENV 13419 specify a general laboratory test method for the determination of the area specific emission rate of volatile organic compounds (VOCs) from newly produced building products under defined climate conditions in a test chamber (Part 1) or cell (Part 2). The third part specifies for solid, liquid or combined products, the sampling procedure, transport and storage conditions and preparation of test specimens. In France, those European prestandards have been translated by the French Normalisation Association (AFNOR) in three experimental standards : XP ENV 13419-1, XP ENV 13419-2 and XP ENV 13419-3 [1-3]. In parallel to the ongoing work at CEN, the technical committee 146 of International Organization for Standardization (ISO) has prepared the draft international standard ISO/DIS 16000 related to indoor air. Part 6 of this standard specifies a method for the determination of the emission of single volatile organic compounds (VOCs) and total volatile organic compounds (TVOC) from building materials using test chambers and cells [4]: ??ISO/DIS 16000-6 : Indoor air - Part 6 : Determination of volatile organic compounds in indoor and chamber air by active sampling on TENAX TA sorbent, thermal desorption and gas chromatography using MS/FID. It is intended that, after the final voting stage, the CEN prestandards (Parts 1-3) will be taken over by ISO and that Part 6 of the ISO standard will be taken over by CEN as the fourth part of the ENV 13419 prestandard. As an example, the volatile organic compounds emissions from preservative treated wood samples were characterised according to the CEN ENV 13419-1 prestandard describing the emission test chamber method and to the ISO/DIS 16000-6 prestandard for the analytical method. Two representative wood preservatives (hydrodispersable and petroleum solvent formulation) were tested for this purpose. The VOCs concentrations in the test chamber were monitored during 6 days following a simulated curative wood treatment.
F Maupetit, O Ramalho, C Yrieix

How to determine what is a realistic emission from treated wood - basic reflections
1998 - IRG/WP 98-50105
Emissions from treated wood occur by evaporation and by leaching. Up to date by far more experience exists on leaching tests than on evaporation test. The methods applied will be of interest to give answers to the questions about the quantity of possible emissions. Standardisation on leaching started very early. One of the first attempts to quantify the effect of leaching on the remaining efficacy was the German DIN 52176-2 (1941) which was the basis for EN 84 first published by CEN in 1978. A specific German standard for the determination of leachates was published in 1972 (DIN 52172-2), however, the viewpoint was still the efficacy of wood preservatives. With respect to pollution of the environment EN 1250-2 (1995) has to be mentioned, however, this is more or less only a modification of EN 84 and as such not very satisfactory. Evaporation tests started as late as in the 50th mainly in connection with fluorides and later with PCP. Examples for a standard to determine the remaining efficacy are the German Pre-Standard DIN 52172-3 (1971) and EN 73, based on the German standard and first published in 1978. A specific standard for emissions is EN 1250-1 (1995). The reflections presented in the paper consider evaporation as well as leaching tests where the general requirements and the statements to the kind of specimens and to the treatment apply to both types of emissions at the same time. For the test procedure itself, however, different methods are needed.
H Willeitner, R-D Peek

Effect of leaching temperature and water acidity on the loss of metal elements from CCA treated timber in aquatic conditions. Part 2: Semi-industrial investigation
1995 - IRG/WP 95-50040-13
In continuation of previous leaching research on the quantification and modelling of metal elements released from CCA treated timber, a series of experiments has been carried out dealing with the influence of temperature and pH of the relative aquatic environment. The leaching method used is the Dutch prestandard for building materials, a long term static leaching test simulating practical bank-shoring situations. Parameters of study are type of fixation, wood species and specimen profiles. With decreasing water temperature, significantly less leaching of copper, chromium and arsenic is observed. An outdoors/indoors temperature ratio of 0.7 could be established. Increasing acidity of the leaching water mainly enhances the release of copper, whereas chromium and arsenic show a minimum leaching tendency at neutral pH. Both conditioning chamber fixation and steam fixation prove to be effective in fixing the metal elements in the wood substrate. With steam fixed timber, however, a higher loss of copper is observed during the early leaching cycles, due to the presence of copper salts on the wood surface. With regard to specimen profiles, boards in comparison with posts demonstrate a remarkable resistance to leaching of active ingredients, presumably due to the different heartwood/sapwood distribution and the specimen dimensions. In conclusion, the observations made confirm the results obtained from previous leaching studies. Converting the emission data into leaching fluxes, a highly correlated double logarithmic flux formula is regarded the best tool for curve fitting, however, for a limited time span. Other models which are more suitable for extrapolation of emitted quantities over a longer period of time are still under investigation. Likewise, proprotional metal ratios versus retention levels highlight the relativity of experimental data obtained with standard emission tests.
G M F Van Eetvelde, W J Homan, H Militz, M Stevens

Emission of trimethyl borate and methanol from radiata pine (Pinus radiata D. Don)
1995 - IRG/WP 95-30088
Sawn and kiln dried radiata pine conditioned to 3, 6, and 12% moisture content was treated with trimethyl borate (TMB). The treated wood samples were placed in mini-desiccators maintained at 20 or 40°C. The air space within the mini-desiccator was analysed for TMB and methanol. An initial period of emission of TMB and methanol was observed. This was followed by a period of gradual dissipation of both TMB and alcohol. There was an equilibrium of 2 ppm and 60 ppm respectively of TMB and methanol for 12% moisture content timber stored at 20°C. Dissipation was slower for 6% and 3% moisture content timber. Higher temperatures resulted in higher concentrations of TMB and methanol during the emission and dissipation stage.
F J Romero, P Vinden, J A Drysdale

Feasibility of termite control using crushed cement-stabilized sludge (Polynite) as a physical barrier and acoustic emission (AE) monitoring
2000 - IRG/WP 00-10381
In Japan, the damages by the subterranean termites (Coptotermes formosanus Shiraki and Reticulitermes speratus Kolbe) are more common. Recently, the more attention is paid to the methods of the termite controls of less- or non-chemical. As one of the non- chemical treatment, physical barrier using particles as basalts 1) , granites, and gravels 2) were investigated in terms of its safety, cost effectiveness and duration of performance, and there were also examples that the physical barriers using some particles have been put to practical use in a few countries except in Japan. Ebeling and Pence showed that the relationship between particle size and termite body size is an important factor in controlling tunneling activity of subterranean termites, and the crushed volcanic cinders of 0.85-2.36 mm in diameter prevented R. hesperus from penetrating 3) . Tamashiro and co- workers indicated that the particles of particular sizes (1.70-2.40 mm in diameter) prevented C. formosanus from penetrating 4) . Su and co- workers investigated the penetration of the sand barrier consisting of crushed quartz rocks and fossilized coral by C. formosanus in laboratory- and field-testing 5, 6) . These results show that it is important to investigate the relationships between the size of termites and particles to evaluate the effects of the physical barrier using particles. On the other hand, in Japan surplus soils and sludge of sixty million tons per annum are discharged from construction sites. The recycle techniques using the surplus soils and sludge and the development of the market for these recycled products are the theme of importance. The crushed cement- stabilized sludge (Polynite) as one of the recycled products of surplus soils and sludge is one of the newly developed and recycled material. It is technically suitable for mass production, has grate cost effectiveness, and is easy to uniform the particle size. In this study, the feasibility of a physical barrier using Polynite uniformed the particle size for termite was examined in a laboratory testing. AE monitoring 7-13) as a method forthe detection of the penetration of termites into the Polynite barrier at an early stage was also investigated, for the application of Polynite barrier in the house.
Y Yanase, M Shibata, Y Fujii, S Okumura, K Iwamoto, T Nogiwa, T Yoshimura, Y Imamura

Feasibility of AE (Acoustic Emission) monitoring for the detection of the activities of wood-destroying insects
1992 - IRG/WP 92-2416
The feasibility of acoustic emission (AE) as a nondestructive testing method for the detection of the wood destroying insects was investigated. AEs were detected from the wood specimens under feeding attack of sugi bark borers or powder-post beetles. However, the feasible monitoring area of an AE sensor is influenced by the attenuation of AE amplitude, so that this could be a problem in the practical AE measurements, especially with wood specimens of higher moisture content.
Y Fujii, Y Imamura, E Shibata, M Noguchi

Detection of Acoustic Emission (AE) generated by termite attack in a wooden house
1999 - IRG/WP 99-20166
Recently, considerable attention has been paid to methods for termite control, which involves few or no chemicals. To reduce the amount of termiticide needed, it is necessary to detect termite attack in wood as early as possible. The feasibility of acoustic emission (AE) monitoring for the nondestructive detection of termite attack has been discussed previously. In this study, we propose some technical solution for the application of AE monitoring to practical control operations. Using a needle-type waveguide combined with an AE sensor (PZT sensor), AEs generated and propagated within floors and walls could be detected effectively. A 0.04 mm-thick sample of the piezoelectric polymer PVDF, which was inserted between the construction members of wooden houses, could detect Aes propagated both in such members and at joint surfaces, although PVDF film is less sensitive than a PZT sensor. The feasibility of using a portable AE detector as the input device for a total security system against termite attack in a house is also discussed.
Y Fujii, Y Yanase, T Yoshimura, Y Imamura, S Okumura, M Kozaki

Detection of termite attack in wood using AE monitoring
1990 - IRG/WP 2355
An acoustic emission (AE) monitoring method for detecting termite activity in wood was applied to lumber of 3 by 3 cm to 10 by 10 cm square, 1 m long. Furthermore, the propagation of AEs due to the feeding activities of termites in the specimens and the locations of AE sources were analyzed. Also discussed was the feasibility of the method applied to posts out in the field of subterranean termites. The results obtained from laboratory and field tests suggest that AE monitoring could be an effective non-destructive method to detect feeding activity of termites even in the incipient stages of the termite attack in wood.
Y Fujii, M Owada, M Noguchi, Y Imamura, M Tokoro

A behavioral assay for measuring feeding deterrency of a slow-acting biocide, A-9248, against the Formosan subterranean termite (Isoptera: Rhinotermitidae)
1988 - IRG/WP 1366
Concentration-dependent feeding deterrency of a slow-acting compound, A-9248 (diiodomethyl para-tolyl sulfone) was studied in a choice test against the Formosan subterranean termite, Coptotermes formosanus Shiraki. A-9248 was a feeding deterrent at concentrations ³8,000 ppm. Initially, Coptotermes formosanus fed on wood treated with 1,000-6,000 ppm A-9248 but learned to avoid the treatment as a result of ingesting sublethal doses of A-9248. Only those groups exposed to wood treated with <1,000 ppm continued feeding on the treated substrates, and ingestion of these concentrations resulted in 85-100% mortality at the end of the 4-week experiment.
N-Y Su, R H Scheffrahn

A Long-term Observation of Termite Activity in The Nest by Continuous Acoustic Emission (AE) Monitoring
2003 - IRG/WP 03-20280
In order to evaluate the influence of temperature on the termite activity, acoustic emission (AE) monitoring was applied to two nests of Coptotermes formosanus SHIRAKI; a nest in the stem of a standing tree and a nest in the underground of a wooden house, respectively. Temperature change in and around the nests were continuously measured for about one year using thermocouples at four points; the centre of the nest, the periphery of the nest, the environment around the nest, and the underground, respectively. AEs were detected at the centre of nest and underneath the nest sphere by using wave-guides inserted into the nest of the standing tree and at the centre of nest. AEs were also detected at the wooden construction member near the nest in the wooden house. The termites in the nests were periodically stimulated by rotating, drawing and sticking the wave-guides. The temperatures in the both nests varied from 5 to 35 °C during the experiment. The highest and the lowest temperatures were recorded in August and February, respectively. The highest AEs event rate was recorded when the temperature of the nest in the tree was between 30 and 35 °C and when the temperature of the nest under the house was above 25 °C. In winter, when the nest temperature was below 10 °C, no significant numbers of AE were detected. These findings clearly show that AE generation has a close relation to the termite activities, which are influenced by the temperature in the nest.
Y Yanase, Y Fujii, S Okumura, T Yoshimura, Y Imamura

International standards and the biocide debate - Potential contribution
2000 - IRG/WP 00-20196
Downstream the European 98/8/EEC directive on biocides, a working party of O.E.C.D. has been developing a tremendous work to put together the background information necessary to assess wood preservative efficacy, environmental and human exposure. Standardization may contribute to those efforts, using traditional experience and methodology. Among them, the hazard classification system may be extended to human beings and their environment, in all situations of uses. While primary exposure to biocides seems to be a matter related to classes of processes, the situation differs with secondary exposure to treated wood, related to use categories: in principle, the doses are already restricted to targets in a given class. Additionally, those uses have been , until now, practically limited to construction products. The first need is to extend the hazard class system to all kinds of biocidal wood preservation and their related uses. A methodology is proposed to get access to biocide concentrations and flows in priority compartments, assessment of intake by non-targets and their ratio to no-effect values in order to quantify safety factors. This route could allow to select further priorities for risk reduction at the pre-marketing stage.
G Ozanne

Effect of soil parameters on biocide depletion: laboratory and field studies of water- and emulsion-borne preservatives
2000 - IRG/WP 00-30234
Two field test sites with different soils were selected. Soil analysis showed that the soil at the two sites had considerable texture, base saturation, acidity, and cation exchange capacity differences. Five sets of field stakes were treated as follows: three with water-borne CCA to about 0.4 pcf (6.4 kgm-3) retention, one with 0.75% DDAC, and one with 0.75% DDAC:0.25% chlorothalonil. The last two sets were treated using oil-in-water emulsions. Samples from all five sets were installed at both field sites. In addition, wood samples which had been co-treated with the five sets of field stakes were installed in a lab environment in fungus cellar tubs using soils from the two sites. All wood samples were defect-free southern yellow pine (SYP) sapwood, with the field stakes measuring 19 x 19 x 457 mm3 and the fungus cellar samples measuring 5 x 19 x 250 mm3. The field samples were exposed for two or three years and the fungus cellar samples for 36 weeks, after which depletion of the various biocides was measured. No consistent pattern in CCA depletions between the two soils were observed in either the fungus cellar or field exposure tests, despite the large chemical and physical differences between the two soils. The fungus cellar method may be useful to conduct relatively rapid depletion studies. The authors also discuss problems with depletion studies, including possible influences by soil, wood, and microorganisms present in the soil.
T Schultz, D D Nicholas, D E Pettry, M G Kim

Environmental risk assessment of treated timber in service: The Environment Focus Group approach
2000 - IRG/WP 00-50162
In the context of the Biocidal Products Directive (98/8/EC), and of the OECD work on wood preservatives, the Environment Focus Group (EFG), comprising 8 institutes and the European Wood Preservative Manufacturers Group, has been working on the environmental risk assessment of treated timber in service. A literature review of emissions from treated timber has revealed that very little existing data is usable for environmental risk assessment; the most relevant data are kinetic curves of emissions over time, which show clearly the non-linear emissions behaviour of treated wood over time. The EFG has suggested real exposure conditions for treated timber in the environment, and listed typical exposure scenarios. Five representative scenarios are characterised in detail, for use in the calculation of Predicted Environmental Concentrations (PECs). The existing methods to determine emissions from treated wood have been reviewed. Most existing experimental models cannot be used to predict environmental emissions. Monitoring of commodities in service has its specific constraints. Chemical analysis and ecotoxicity testing have also been reviewed and their relationship has been discussed. Principles for the design of experimental models, for the determination of emission fluxes from treated wood to the environment, have been established.
G Deroubaix, G Labat, I Le Bayon, S Legay, P Marchal, C Yrieix, E Melcher, R-D Peek, S De Geyter, J Van Acker, W J Homan, D J Dickinson, R J Murphy, E D Suttie, A J Nurmi, A-C Ritschkoff, D Rudolph, I Stephan, D Aston, E F Baines, J B Simonin

Comparative study on leaching of CCA from treated timber: Modelling of emission data
1994 - IRG/WP 94-50027
Results of a comparative study on leaching of CCA from treated timber are reported. The study aims at investigating the applicability of prestandard leaching test methods for modelling purposes. Prestandards used are the European standard proposed by CEN/TC38/WG11 and NEN 7345 (Dutch prestandard for building materials). Parameters of study are type of fixation, wood species (pine - spruce), specimen dimensions and leaching pH. Due to the conditions of test, a higher level of metal emission is observed in the CEN procedure. Both methods show a similar time-related decrease in leaching flux, however. The CEN small wood block test using a dynamic stirring leaching system proves to be an accellerated version of the static NEN method in which pole sections are immersed in water over a long period of time. Steam fixation generally reduces the emitted quantities of chromium. When naturally fixated, the initial chromium flux exceeds the copper flux, while in accelerated (steam) fixation tests copper is leached out to a higher level. In most tests the initial arsenicum emission flux does not exceed one tenth of the respective copper flux. With regard to hazard assessment of CCA leaching from treated timber in surface waters, an emission model is worked out taking into account a number of controlable and verifiable parameters influencing the final environmental concentration. The PEC-formula used (predictable environmental concentration) is kept short and is based on time dependency of the emission data (curve fitting on experimental data) and substraction of calculated dilution factors.
G M F Van Eetvelde, M Stevens, L Van der Mijnsbrugge

Using AE monitoring for detecting economically important species of termites in California
1991 - IRG/WP 2375
Acoustic emission (AE) monitoring was conducted on wooden samples containing three economically important species of termites in California (dampwood termite, Zootermopsis nevadensis, Western drywood termite, Incisitermes minor, and Western subterranean termite, Reticulitermes hesperus). Laboratory AE studies included varying termite species, as well as 7 day studies exploring the periodicity of termite behavior. The results from the laboratory tests revealed significant differences in AE events between species, days, and sensors used. In a second study, the distance that AE signals could be detected in 2.6 m (8 ft.) long, 52 x 102 mm² (2 by 4 in.) wooden studs was also explored for the dampwood termite. Acoustic emission signals were detectable for up to 2.2 m in wood for dampwood termites. This study is compared with other investigations exploring the feasibility of using AE to detect termites.
V R Lewis, R L Lemaster, F C Beall, D L Wood

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