Upright Metallurgical Microscope

What is the Upright Metallurgical Microscope?

An upright metallurgical microscope views mounted specimens from above in reflected light. It is the standard configuration for prepared metallographic samples, coatings and small parts in materials laboratories. It combines a compact stand with reflected illumination.

Overview

An upright metallurgical microscope places the objective above the stage and illuminates the specimen through the objective, so a polished surface facing upward is examined in reflected light. The sample is normally a mounted, ground and polished specimen of convenient size resting on the stage. Brightfield reflection reveals phases and grain structure, and an analyser and polarizer can add polarized-light observation. A vertical illuminator with field and aperture diaphragms controls illumination for Köhler alignment. Plan objectives give flat fields for measurement and photography, and a trinocular head allows a camera. The configuration is compact, rigid and suited to routine metallography.

How does it work?

A metallurgical microscope illuminates the specimen from the same side as the objective, so light reflects off the surface and returns through the objective to the eyepiece or camera. Because the sample is opaque, transmitted illumination is not used. Brightfield reflection shows phases and structures by differences in reflectivity. Darkfield uses oblique illumination to reveal scratches, edges and fine particles. Polarized light and differential interference contrast add information about anisotropy and surface relief. Specimens are usually mounted in resin, ground and polished, and often etched to reveal grain boundaries. Objective numerical aperture, illumination type and surface preparation determine what can be resolved.

What are the key features?

• Objectives above the stage for reflected light
• Vertical illuminator with field and aperture diaphragms
• Polarizer and analyser for polarized observation
• Plan objectives for flat fields of view
• Trinocular head for camera attachment

What are the technical specifications?

A typical upright metallurgical microscope configuration offers optical system of Infinite corrected, magnification range of 50×–1000×, objectives of 5×, 10×, 20×, 50×, 100× plan, illumination of Reflected, 12 V 50 W halogen or LED, contrast modes of Brightfield and polarized and stage of Mechanical, 180 × 150 mm. Values are indicative of the product class; the exact figures for each configuration are confirmed on the quotation and the calibration documents supplied with the instrument.

Which applications is it used for?

The Upright Metallurgical Microscope is used in metals and alloys microstructure analysis, heat-treatment and welding evaluation, coating thickness and integrity checks and failure analysis of components. Across the wider Metallurgical Microscopes class, laboratories also deploy it for metals and alloys grain structure analysis, welding and heat-treatment evaluation and failure analysis and defect investigation.

Which standards and certifications apply?

Relevant standards and methods include ASTM E3, ASTM E407, ASTM E112, ISO 643 and IEC 61010-1. Certification candidates for this model are CE and ISO 9001 manufacturing; each is to be confirmed for the specific configuration before shipment, and certificates are supplied only where they have been issued.

Specimen preparation dominates image quality, so follow a consistent grinding and polishing procedure, and etch according to the relevant standard. Keep the objective and the specimen surface free of dust, oil and residue, and avoid scratching coatings. Cover the specimen when not in use to prevent oxidation and contamination. Verify the illumination alignment and, for polarized work, use strain-free objectives and a centred polarizer. Calibrate measurements with a stage micrometer for each objective and record the scale. Service the stage and focus mechanisms, and check the lamp or diode output on a schedule.

How do I select the right Upright Metallurgical Microscope?

Select an upright metallurgical microscope for prepared mounted specimens of modest size. Confirm the contrast modes cover the required assessment and that plan objectives are available for measurement and imaging. Check the stage size for the specimens and the illumination for the materials' reflectivity. Add polarized optics if anisotropic phases must be examined.

How does it compare with other Metallurgical Microscopes variants?

Choose a metallurgical microscope for opaque, reflective specimens examined in reflected light. Decide the contrast methods required: brightfield for general structure, darkfield for defects and fine features, and polarized light or differential interference contrast for anisotropy and relief. Confirm the stage can hold the sample format, including mounted specimens, large parts or wafers. Consider upright models for small mounted samples and inverted models for larger ones. Select plan objectives for flat fields of view and a camera suited to measurement and documentation. For grain-size or phase measurement, check that measurement software and calibration are available.