Optics and optical instruments — Microscopes — Part 1: Immersion oil for general use in light microscopy

Optics and optical instruments — Microscopes — Part 1: Immersion oil for general use in light microscopy

Optics and photonics — Microscopes — Immersion liquids for light microscopy

Microscopes — Immersion liquids for light microscopy

Optics and optical instruments — Microscopes — Slides — Part 1: Dimensions, optical properties and marking

Optics and optical instruments — Microscopes — Slides — Part 2: Quality of material, standards of finish and mode of packaging

Optics and optical instruments — Microscopes — Slides — Part 2: Quality of material, standards of finish and mode of packaging — Technical Corrigendum 1

Optics and optical instruments — Microscopes — Screw threads for objectives and related nosepieces — Part 1: Screw thread type RMS (4/5 in x 1/36 in)

Optics and optical instruments — Screw threads for microscope objectives and related nosepieces — Part 2: Screw thread type M25 X 0,75 mm

Optics and optical instruments — Microscopes — Screw thread for objectives

Microscopes — Screw threads for objectives and related nosepieces

Microscopes — Screw threads for objectives and related nosepieces

Optics and optical instruments — Microscopes — Magnification

Microscopes — Values, tolerances and symbols for magnification

Microscopes — Values, tolerances and symbols for magnification

Optics and optical instruments — Microscopes — Connecting dimensions of tube slides and tube slots

Optics and optical instruments — Microscopes — Dimensions of tube slide and tube slot connections

Optics and optical instruments — Microscopes — Cover glasses — Part 1: Dimensional tolerances, thickness and optical properties

Microscopes — Cover glasses — Part 1: Dimensional tolerances, thickness and optical properties

Microscopes — Cover glasses — Part 1: Dimensional tolerances, thickness and optical properties

Optics and optical instruments — Microscopes — Cover glasses — Part 2: Quality of materials, standards of finish and mode of packaging

Microscopes — Cover glasses — Part 2: Quality of materials, standards of finish and mode of packaging

Optics and optical instruments — Microscopes — Reference system of polarized light microscopy

Optics and optical instruments — Microscopes — Spectral filters

Microscopes — Marking of objectives and eyepieces

Microscopes — Marking of objectives and eyepieces — Technical Corrigendum 1

Microscopes — Marking of objectives and eyepieces

Optics and photonics — Medical endoscopes and endotherapy devices — Part 5: Determination of optical resolution of rigid endoscopes with optics

Optics and photonics — Medical endoscopes and endotherapy devices — Part 6: Vocabulary

Endoscopes — Medical endoscopes and endotherapy devices — Part 5: Determination of optical resolution of rigid endoscopes with optics

Endoscopes — Medical endoscopes and endotherapy devices — Part 6: Vocabulary

Optics and optical instruments — Environmental test methods — Part 10: Combined sinusoidal vibration, dry heat or cold

Optics and optical instruments — Environmental test methods — Part 10: Combined sinusoidal vibration and dry heat or cold

Optics and optical instruments — Environmental test methods — Part 11: Mould growth

Optics and photonics — Environmental test methods — Part 11: Mould growth

Optics and optical instruments — Environmental test methods — Part 12: Contamination

Optics and photonics — Environmental test methods — Part 12: Contamination

Optics and optical instruments — Environmental test methods — Part 13: Combined shock, bump or free fall, dry heat or cold

Optics and optical instruments — Environmental test methods — Part 13: Combined shock, bump or free fall and dry heat or cold

Optics and optical instruments — Environmental test methods — Part 14: Dew, hoarfrost, ice

Optics and photonics — Environmental test methods — Part 14: Dew, hoarfrost, ice

Optics and optical instruments — Environmental test methods — Part 15: Combined random vibration wide band: reproducibility medium, in dry heat or cold

Optics and optical instruments — Environmental test methods — Part 15: Combined digitally controlled broad-band random vibration and dry heat or cold

Optics and optical instruments — Environmental test methods — Part 16: Combined bounce or steady-state acceleration, in dry heat or cold

Optics and optical instruments — Environmental test methods — Part 16: Combined bounce or steady-state acceleration and dry heat or cold

Optics and optical instruments — Environmental test methods — Part 17: Combined contamination, solar radiation

Optics and photonics — Environmental test methods — Part 17: Combined contamination, solar radiation

Optics and optical instruments — Environmental test methods — Part 18: Combined damp heat and low internal pressure

Optics and optical instruments — Environmental test methods — Part 19: Temperature cycles combined with sinusoidal or random vibration

Optics and optical instruments — Environmental test methods — Part 1: Definitions, extent of testing

Optics and photonics — Environmental test methods — Part 1: Definitions, extent of testing

Optics and photonics — Environmental test methods — Part 1: Definitions, extent of testing

Optics and optical instruments — Environmental test methods — Part 20: Humid atmosphere containing sulfur dioxide or hydrogen sulfide

Optics and photonics — Environmental test methods — Part 20: Humid atmosphere containing sulfur dioxide or hydrogen sulfide

Optics and optical instruments — Environmental test methods — Part 21: Combined low pressure and ambient temperature or dry heat

Optics and photonics — Environmental test methods — Part 22: Combined cold, dry heat or temperature change with bump or random vibration

Optics and photonics — Environmental test methods — Part 23: Low pressure combined with cold, ambient temperature and dry and damp heat

Optics and photonics — Environmental test methods — Part 23: Low pressure combined with cold, ambient temperature and dry or damp heat

Optics and optical instruments — Environmental test methods — Part 2: Cold, heat, humidity

Optics and optical instruments — Environmental test methods — Part 2: Cold, heat and humidity

Optics and photonics — Environmental test methods — Part 2: Cold, heat and humidity

Optics and optical instruments — Environmental test methods — Part 3: Mechanical stress

Optics and optical instruments — Environmental test methods — Part 3: Mechanical stress

Optics and photonics — Environmental test methods — Part 3: Mechanical stress

Optics and photonics — Environmental test methods — Part 3: Mechanical stress — Amendment 1

Optics and optical instruments — Environmental test methods — Part 4: Salt mist

Optics and optical instruments — Environmental test methods — Part 4: Salt mist

Optics and photonics — Environmental test methods — Part 4: Salt mist

Optics and optical instruments — Environmental test methods — Part 5: Combined cold, low air pressure

Optics and optical instruments — Environmental test methods — Part 6: Dust

Optics and photonics — Environmental test methods — Part 6: Dust

Optics and optical instruments — Environmental test methods — Part 7: Drip, rain

Optics and optical instruments — Environmental test methods — Part 7: Drip, rain — Technical Corrigendum 1

Optics and photonics — Environmental test methods — Part 7: Resistance to drip or rain

Optics and photonics — Environmental test methods — Part 7: Resistance to drip or rain

Optics and optical instruments — Environmental test methods — Part 8: High pressure, low pressure, immersion

Optics and photonics — Environmental test methods — Part 8: High internal pressure, low internal pressure, immersion

Optics and optical instruments — Environmental test methods — Part 9: Solar radiation

Optics and photonics — Environmental test methods — Part 9: Solar radiation and weathering

Optics and optical instruments — Quality evaluation of optical systems — Determination of distortion

Optics and optical instruments — Quality evaluation of optical systems — Determination of distortion — Technical Corrigendum 1

Optics and photonics — Quality evaluation of optical systems — Determination of distortion

Optics and optical instruments — Optical coatings — Part 1: Definitions

Optics and photonics — Optical coatings — Part 1: Definitions

Optics and photonics — Optical coatings — Part 1: Vocabulary

Optics and optical instruments — Optical coatings — Part 2: Optical properties

Optics and photonics — Optical coatings — Part 2: Optical properties

Optics and optical instruments — Optical coatings — Part 3: Environmental durability

Optics and photonics — Optical coatings — Part 3: Environmental durability

Optics and optical instruments — Optical coatings — Part 4: Specific test methods

Optics and optical instruments — Optical coatings — Part 4: Specific test methods

Optics and photonics — Optical coatings — Part 4: Specific test methods

Optics and photonics — Optical coatings — Part 5: Minimum requirements for antireflecting coatings

Optics and photonics — Optical coatings — Part 6: Minimum requirements for reflecting coatings

Optics and photonics — Optical coatings — Part 7: Minimum requirements for neutral beam splitter coatings

Optics and photonics — Optical coatings — Part 8: Minimum requirements for coatings used for laser optics

Optics and optical instruments — Optical transfer function — Application — Part 2: Lenses for office copiers

Optics and optical instruments — Optical transfer function — Application — Part 3: Telescopes

Optics and photonics — Optical transfer function — Application — Part 3: Telescopes

Optics and optical instruments — Microscopes — Graticules for eyepieces

Microscopes — Graticules for eyepieces

Microscopes — Graticules for eyepieces

Optics and optical instruments — Microscopes — Imaging distances related to mechanical reference planes — Part 1: Tube length 160 mm

Microscopes — Imaging distances related to mechanical reference planes — Part 1: Tube length 160 mm

Optics and optical instruments — Microscopes: Imaging distances related to mechanical reference planes — Part 2: Infinity-corrected optical systems

Microscopes — Imaging distances related to mechanical reference planes — Part 2: Infinity-corrected optical systems

Microscopes — Interfacing dimensions for imaging components

Optics and optical instruments — Veiling glare of image forming systems — Definitions and methods of measurement

Optics and optical instruments — Environmental requirements — Part 11: Optical instruments for outdoor conditions of use

Optics and optical instruments — Environmental requirements — Part 12: Conditions of transport for optical instruments

Optics and optical instruments — Environmental requirements — Part 1: General information, definitions, climatic zones and their parameters

Optics and photonics — Environmental requirements — Part 1: General overview, terms and definitions, climatic zones and their parameters

Optics and optical instruments — Environmental requirements — Part 4: Test requirements for telescopic systems

Optics and optical instruments — Environmental requirements — Part 6: Test requirements for medical optical devices

Optics and photonics — Environmental requirements — Part 6: Test requirements for medical optical instruments

Optics and optical instruments — Environmental requirements — Part 7: Test requirements for optical measuring instruments

Optics and optical instruments — Environmental requirements — Part 8: Test requirements for extreme conditions of use

Optics and photonics — Environmental requirements — Part 8: Test requirements for extreme conditions of use

Optics and photonics — Guidance for the selection of environmental tests

Optics and photonics — Guidance for the selection of environmental tests

Optics and optical instruments — Preparation of drawings for optical elements and systems — Part 10: Table representing data of a lens element

Optics and photonics — Preparation of drawings for optical elements and systems — Part 10: Table representing data of optical elements and cemented assemblies

Optics and photonics — Preparation of drawings for optical elements and systems — Part 11: Non-toleranced data

Optics and photonics — Preparation of drawings for optical elements and systems — Part 11: Non-toleranced data — Technical Corrigendum 1

Optics and photonics — Preparation of drawings for optical elements and systems — Part 11: Non-toleranced data

Optics and photonics — Preparation of drawings for optical elements and systems — Part 12: Aspheric surfaces

Optics and optical instruments — Preparation of drawings for optical elements and systems — Part 12: Aspheric surfaces

Optics and photonics — Preparation of drawings for optical elements and systems — Part 12: Aspheric surfaces

Optics and photonics — Preparation of drawings for optical elements and systems — Part 12: Aspheric surfaces — Amendment 1

Optics and optical instruments — Preparation of drawings for optical elements and systems — Part 14: Wavefront deformation tolerance

Optics and photonics — Preparation of drawings for optical elements and systems — Part 14: Wavefront deformation tolerance

Optics and photonics — Preparation of drawings for optical elements and systems — Part 14: Wavefront deformation tolerance

Optics and photonics — Preparation of drawings for optical elements and systems — Part 17: Laser irradiation damage threshold

Optics and photonics — Preparation of drawings for optical elements and systems — Part 18: Stress birefringence, bubbles and inclusions, homogeneity, and striae

Optics and photonics — Preparation of drawings for optical elements and systems — Part 19: General description of surfaces and components

Optics and optical instruments — Preparation of drawings for optical elements and systems — Part 1: General

Optics and photonics — Preparation of drawings for optical elements and systems — Part 1: General

Optics and photonics — Preparation of drawings for optical elements and systems — Part 1: General

Optics and optical instruments — Preparation of drawings for optical elements and systems — Part 2: Material imperfections — Stress birefringence

Optics and optical instruments — Preparation of drawings for optical elements and systems — Part 3: Material imperfections — Bubbles and inclusions

Optics and optical instruments — Preparation of drawings for optical elements and systems — Part 4: Material imperfections — Inhomogeneity and striae

Optics and optical instruments — Preparation of drawings for optical elements and systems — Part 5: Surface form tolerances

Optics and optical instruments — Preparation of drawings for optical elements and systems — Part 5: Surface form tolerances — Technical Corrigendum 1

Optics and photonics — Preparation of drawings for optical elements and systems — Part 5: Surface form tolerances

Optics and photonics — Preparation of drawings for optical elements and systems — Part 5: Surface form tolerances

Optics and optical instruments — Preparation of drawings for optical elements and systems — Part 6: Centring tolerances

Optics and optical instruments — Preparation of drawings for optical elements and systems — Part 6: Centring tolerances — Technical Corrigendum 1

Optics and photonics — Preparation of drawings for optical elements and systems — Part 6: Centring tolerances

Optics and optical instruments — Preparation of drawings for optical elements and systems — Part 7: Surface imperfection tolerances

Optics and photonics — Preparation of drawings for optical elements and systems — Part 7: Surface imperfection tolerances

Optics and photonics — Preparation of drawings for optical elements and systems — Part 7: Surface imperfections

Optics and optical instruments — Preparation of drawings for optical elements and systems — Part 8: Surface texture

Optics and photonics — Preparation of drawings for optical elements and systems — Part 8: Surface texture; roughness and waviness

Optics and photonics — Preparation of drawings for optical elements and systems — Part 8: Surface texture

Optics and optical instruments — Preparation of drawings for optical elements and systems — Part 9: Surface treatment and coating

Optics and photonics — Preparation of drawings for optical elements and systems — Part 9: Surface treatment and coating

Optics and optical instruments — Vocabulary for microscopy — Part 1: Light microscopy

Optics and optical instruments — Vocabulary for microscopy — Part 2: Advanced techniques in light microscopy

Microscopes — Vocabulary for light microscopy

Optics and optical instruments — Microscopes — Interfacing connection type C

Microscopes — Interfacing connection type C

Optics and optical instruments — Operation microscopes — Part 1: Requirements and test methods

Optics and photonics — Operation microscopes — Part 1: Requirements and test methods

Optics and optical instruments — Operation microscopes — Part 2: Light hazard from operation microscopes used in ocular surgery

Optics and photonics — Operation microscopes — Part 2: Light hazard from operation microscopes used in ocular surgery

Optics and optical instruments — Microscopes — Diameter of interchangeable eyepieces for microscopes with tube length 160 mm

Optics and optical instruments — Microscopes — Diameter of interchangeable eyepieces

Optics and photonics — Optical materials and components — Characterization of optical materials used in the infrared spectral range from 0,78 µm to 25 µm

Optics and optical instruments — Microscopes — Interfacing connection for 35 mm SLR photo cameras (T-thread adaptation)

Optics and optical instruments — Microscopes — Marking of stereomicroscopes

Optics and optical instruments — Minimum requirements for stereomicroscopes — Part 1: Stereomicroscopes for general use

Optics and photonics — Minimum requirements for stereomicroscopes — Part 1: Stereomicroscopes for general use

Optics and optical instruments — Minimum requirements for stereomicroscopes — Part 2: High performance microscopes

Optics and photonics — Minimum requirements for stereomicroscopes — Part 2: High performance microscopes

Optics and optical instruments — Microscopes — Information provided to the user

Microscopes — Information provided to the user

Optics and photonics — Lasers and laser-related equipment — Test methods for the spectral characteristics of lasers

Optics and optical instruments — Vocabulary for telescopic systems — Part 1: General terms and alphabetical indexes of terms in ISO 14132

Optics and photonics — Vocabulary for telescopic systems — Part 1: General terms and alphabetical indexes of terms in ISO 14132

Optics and optical instruments — Vocabulary for telescopic systems — Part 2: Terms for binoculars, monoculars and spotting scopes

Optics and optical instruments — Vocabulary for telescopic systems — Part 2: Terms for binoculars, monoculars and spotting scopes — Technical Corrigendum 1

Optics and photonics — Vocabulary for telescopic systems — Part 2: Terms for binoculars, monoculars and spotting scopes

Optics and optical instruments — Vocabulary for telescopic systems — Part 3: Terms for telescopic sights

Optics and photonics — Vocabulary for telescopic systems — Part 3: Terms for telescopic sights

Optics and optical instruments — Vocabulary for telescopic systems — Part 4: Terms for astronomical telescopes

Optics and photonics — Vocabulary for telescopic systems — Part 4: Terms for astronomical telescopes

Optics and photonics — Vocabulary for telescopic systems — Part 5: Terms for night vision devices

Optics and photonics — Vocabulary for telescopic systems — Part 3: Terms for telescopic sights

Optics and photonics — Vocabulary for telescopic systems — Part 5: Terms for night vision devices

Optics and optical instruments — Specifications for binoculars, monoculars and spotting scopes — Part 1: General purpose instruments

Optics and photonics — Specifications for binoculars, monoculars and spotting scopes — Part 1: General purpose instruments

Optics and optical instruments — Specifications for binoculars, monoculars and spotting scopes — Part 2: High performance instruments

Optics and photonics — Specifications for binoculars, monoculars and spotting scopes — Part 2: High performance instruments

Optics and optical instruments — Specifications for astronomical telescopes

Optics and optical instruments — Specifications for telescopic sights — Part 1: General-purpose instruments

Optics and photonics — Specifications for telescopic sights — Part 1: General-purpose instruments

Optics and photonics — Specifications for telescopic sights — Part 1: General-purpose instruments

Optics and optical instruments — Specifications for telescopic sights — Part 2: High-performance instruments

Optics and photonics — Specifications for telescopic sights — Part 2: High-performance instruments

Optics and photonics — Specifications for telescopic sights — Part 2: High-performance instruments

Optics and photonics - Specifications for telescopic sights — Part 1: General-purpose instruments

Optics and photonics — Specifications for telescopic sights — Part 2: High-performance instruments

Optics and optical instruments — Test methods for telescopic systems — Part 1: Test methods for basic characteristics

Optics and optical instruments — Test methods for telescopic systems — Part 2: Test methods for binocular systems

Optics and optical instruments — Test methods for telescopic systems — Part 3: Test methods for telescopic sights

Optics and photonics — Test methods for telescopic systems — Part 3: Test methods for telescopic sights

Optics and optical instruments — Test methods for telescopic systems — Part 4: Test methods for astronomical telescopes

Optics and optical instruments — Test methods for telescopic systems — Part 5: Test methods for transmittance

Optics and optical instruments — Test methods for telescopic systems — Part 5: Test methods for transmittance — Amendment 1

Optics and photonics — Test methods for telescopic systems — Part 5: Test methods for transmittance

Optics and optical instruments — Test methods for telescopic systems — Part 6: Test methods for veiling glare index

Optics and photonics — Test methods for telescopic systems — Part 6: Test methods for veiling glare index

Optics and optical instruments — Test methods for telescopic systems — Part 7: Test methods for limit of resolution

Optics and photonics — Test methods for telescopic systems — Part 7: Test methods for limit of resolution

Optics and optical instruments — Test methods for telescopic systems — Part 8: Test methods for night-vision devices

Optics and photonics — Test methods for telescopic systems — Part 9: Test methods for field curvature

Optics and optical instruments — Test methods for telescopic systems — Part 3: Test methods for telescopic sights

Optics and photonics — Test methods for telescopic systems — Part 5: Test methods for transmittance

Optics and optical instruments — Test methods for telescopic systems — Part 8: Test methods for night-vision devices

Optics and photonics — Test methods for telescopic systems — Part 10: Test methods for axial colour performance

Optics and optical instruments — Test methods for surface imperfections of optical elements

Optics and photonics — Test methods for surface imperfections of optical elements

Optics and photonics — Test methods for surface imperfections of optical elements

Optics and photonics — Interferometric measurement of optical elements and optical systems — Part 4: Interpretation and evaluation of tolerances specified in ISO 10110

Optics and photonics — Interferometric measurement of optical elements and optical systems — Part 4: Interpretation and evaluation of tolerances specified in ISO 10110

Optics and photonics — Interferometric measurement of optical elements and optical systems — Part 1: Terms, definitions and fundamental relationships

Optics and photonics — Interferometric measurement of optical elements and optical systems — Part 2: Measurement and evaluation techniques

Optics and photonics — Interferometric measurement of optical elements and optical systems — Part 2: Measurement and evaluation techniques

Optics and photonics — Interferometric measurement of optical elements and optical systems — Part 3: Calibration and validation of interferometric test equipment and measurements

Optics and optical instruments — Microscopes — Testing of stereomicroscopes

Optics and optical instruments — Stereomicroscopes — Information provided to the user

Stereomicroscopes — Information provided to the user

Microbeam analysis — Instrumental specification for energy dispersive X-ray spectrometers with semiconductor detectors

Optics and optical instruments — Quality evaluation of optical systems — Assessing the image quality degradation due to chromatic aberrations

Optics and optical instruments — Quality evaluation of optical systems — Assessing the image quality degradation due to chromatic aberrations — Technical Corrigendum 1

Microbeam analysis — Analytical electron microscopy — Vocabulary

Microbeam analysis — Scanning electron microscopy — Guidelines for calibrating image magnification

Microbeam analysis — Scanning electron microscopy — Guidelines for calibrating image magnification

Optics and photonics — Wavefront sensors for characterising optical systems and optical components

Optics and photonics — Optical materials and components — Test method for refractive index of infrared optical materials

Optics and photonics — Optical materials and components — Test method for homogeneity of optical glasses by laser interferometry

Microscopes — Microscopes with digital imaging displays — Information provided to the user regarding imaging performance

Optics and photonics — Designation of microscope objectives — Part 1: Flatness of field/Plan

Microscopes — Designation of microscope objectives — Part 1: Flatness of field/Plan

Microscopes — Designation of microscope objectives — Part 1: Flatness of field/Plan

Optics and photonics — Designation of microscope objectives — Part 2: Chromatic correction

Microscopes — Designation of microscope objectives — Part 2: Chromatic correction

Microscopes — Designation of microscope objectives — Part 3: Spectral transmittance

Microscopes — Minimum requirements for binocular tubes

Microscopes — Definition and measurement of illumination properties — Part 1: Image brightness and uniformity in bright field microscopy

Microscopes — Definition and measurement of illumination properties — Part 2: Illumination properties related to the colour in bright field microscopy

Optics and photonics — Optical materials and components — Test method for homogeneity of infrared optical materials

Optics and photonics — Optical materials and components — Test method for striae in infrared optical materials

Optics and photonics — Optical materials and components — Test method for bubbles and inclusions in infrared optical materials

Microbeam analysis — Scanning electron microscopy — Tagged image file format for scanning electron microscopy(TIFF/SEM)

Microbeam analysis — Analytical electron microscopy — Method for the determination of interface position in the cross-sectional image of the layered materials

Optics and photonics — Spectral bands

Optics and photonics — Environmental requirements — Test requirements for telescopic systems

Microscopes — Confocal microscopes — Optical data of fluorescence confocal microscopes for biological imaging

Optics and photonics — Telescopic systems — Specifications for night vision devices

Optics and photonics — Telescopic systems — Specifications for night vision devices

Qualification of the scanning electron microscope for quantitative measurements

Optics and photonics — Test method for refractive index of optical glasses — Part 1: Minimum deviation method

Microbeam analysis — Scanning electron microscopy — Method for evaluating critical dimensions by CD-SEM

Optics and photonics — Preparation of drawings for optical elements and systems — Surface imperfection specification and measurement systems

Optics and photonics — Optical materials and components — The powder test method for the water resistance of optical glass

Microbeam analysis — Scanning electron microscopy — Vocabulary

Microbeam analysis — Scanning electron microscopy — Vocabulary

Optics and photonics — Optical materials and components — Test method for climate resistance of optical glass

Optics and photonics — Optical materials and components — Specification of calcium fluoride used in the infrared spectrum

Optics and Photonics — Bulk absorption optical filters

Optics and photonics — Specification of reference dictionary — Part 1: General overview on organization and structure

Optics and photonics — Specification of reference dictionary — Part 2: Classes' and properties' definitions

Microbeam analysis — Scanning electron microscopy — Methods of evaluating image sharpness

Optics and photonics — Electronic exchange of optical data — Part 1: NODIF information model

Optics and photonics — Electronic exchange of optical data — Part 1: NODIF information model

Optics and photonics — Electronic exchange of optical data — Part 2: Mapping to the classes and properties defined in ISO 23584

Microbeam analysis — Analytical transmission electron microscopy — Methods for calibrating image magnification by using reference materials having periodic structures

Microbeam analysis — Analytical electron microscopy — Methods for calibrating image magnification by using reference materials with periodic structures