AS NZS 1605.3:2018 pdf free
AS NZS 1605.3:2018 pdf free.Methods for sampling and analysing timber preservatives and preservative-treated timber
Analytical methods may be used where no effective spot test is available. In such cases, the sample shall be taken from the central ninth of the sapwood penetration zone.
Where heartwood penetration or an envelope is specified, additional samples shall be taken adjacent to the boundary of the required penetration zone. Each sample taken shall be analysed individually for the presence of preservative. For example, in the case of an H3 sample, the central ninth of the penetration zone is required to be analysed as one sample,and samples taken from the heartwood analysed separately.
The analytical methods given in this Standard are intended as referee methods for the determination of timber preservative retentions. Alternative methods should be compared with methods presented in this Standard before being routinely used, provided that they are of comparable accuracy, e.g. copper chromium arsenic (CCA) treated timber may be analysed by atomic absorption spectrophotometry (AAS), X-ray diffraction (XRF), oIinductively-coupled plasma (ICP) methods, and boron-treated timber by alternative water extracted titration method.
Copper, chromium and arsenic compounds are leached quantitatively from the timber sample with a mixture of diluted sulphuric acid and hydrogen peroxide solution. After adding sodium sulphate to the resulting extracts,the elemental concentrations are determined by atomic absorption spectrophotometry.
NOTE: The method may be used for copper alone in determining the copper content in timber treated with copper-based preservatives.
Several different types of ion-selective meters are available， and each has different operating characteristics. The operating manual shall be followed.
Particular attention shall be given to measuring electrode slope and setting the meter to the current slope value; solutions shall be gently stirred during electrode equilibration.
A high-performance liquid-chromatography system shall be used. The system shall be capable of step-gradient in solvent composition at a specified run time, with UV detection at 220 nm and peak area integration. Ultrasonic treatment shall be carried out using a thermally insulated ultrasonic bath with a power rating of approximately 50 W/L.AS NZS 1605.3 pdf free download.
