BS EN 12407 pdf free download

BS EN 12407-2019 pdf free download.Natural stone test methods – Petrographic examination.
6.6 Extractor hood.
6.7Glassplatec.300mmx400mmx10mm.
6.8 Soft bristle brush.
6.9 Ultrasonic tank.
6.10 Polarized transmitted light optical microscope.
6.11 Point counter and image analysis system (if required).
6.12 Reactives and products as e.g: emery with varying grain size (30 um to 10 um), epoxy resin, Canada balsam, supporting glass (at least 28 mm x48 mm x1,8 mm), cover glass (24 mm x32 mm), diamond disks, xylene and ethanol, amaranth, sodium cobaltinitrite, hydrofluoric acid, hydrochloric acid, sulphosodic alizarin. To facilitate the identification of some minerals with similar colours or optical properties it might be necessary in many cases to use dfferent techniques such as: selective mineral staining methods, optical cathodoluminescence, XRD, SEM-EDS or WDS microprobe. If required, these methods should be clearly stated in the working order referring to widely-referenced manuals, but taking into account that such additional techniques are not part of the petrographic analysis described in this standard.
7 Preparation of thin and polished sections
7.1 General Sampling is not responsibility of the test laboratory except where specially requested. The dimensions of the sample shall be large enough to be representative of the petrographic characteristics of the stone being examined. One or more thin sections are then prepared. A thin section is a portion of material mounted on a slide and mechanically reduced to a thin sheet measuring 0,030土0,005 mm in thickness, and normally protected by a slide cover. For special purposes (observations under reflected light microscope for the determination of opaque minerals or microprobe analysis) polished thin sections shall be prepared. Polished sections have one side polished with a first polishing paste (in the range oft 5 um to 12 um grade) and a second paste (in the range of土6um,3umand1um). The section normally measures about 44 mm x 28 mm, but in the case of coarser grain size stones, larger dimensions may be used (e.g. 75 mm x 50 mm) or several sections of normal dimensions can be prepared. If the rock texture is anisotropic it is necessary to prepare at least two sections with different orientation with respect to the anisotropy (e.g. parallel and perpendicular to anisotropy planes). Preparation of thick sections The sample shall be sufficiently coherent so as not to disintegrate when cut. If the stone is brittle or fragile, it will be necessary to strengthen it by means of impregnation, preferably in a vacuum, with resins with an index of refraction approximately 1,54 (e.g epoxy resins). By using the rock saw, several small blocks are cut of dimensions in the range ofat least土4-5cmx土3- 4 cm and thickness in the range of+3 to 4 mm thick. In case of porous samples pores are flled with Canada balsam (or any synthetic resin with approximately equivalent refractive index); the samples are then heated on the plate to approximately 100 °C and then cooled.
Blocks are then successively ground using diamond discs between 1 and 2 min depending on the type and hardness of their constituent minerals.
Preparation of thin sections
The detailed description of preparation of thin sections is given in Annex A (informative).
7.2 Staining
7.2.1 Feldspar staining
The detailed description of feldspar staining preparation and procedure is given in Annex B (informative).BS EN 12407 pdf download.