Kern OPM 181 Trinocular Polarization Transmitted Halogen

Description

Identify birefringent mineral thin sections using the Kern OPM 181 Trinocular Polarizing Microscope across university geology classrooms and petrographic testing suites. Powered by an infinity-corrected IOS optical pathway, it delivers 40x, 100x, and 400x magnification through three stress-free Infinity Plan objectives: 4x/0.10, 10x/0.25, and spring-loaded 40x/0.65. The 30-degree inclined trinocular head incorporates an integrated beam-splitting photo channel alongside paired high-eyepoint HWF 10x/20 mm eyepieces, including one eyepiece with an embedded crosshair target reticle for measuring extinction angles.

Transmitted light comes from an adjustable 6V/20W halogen bulb focused through an Abbe 1.25 NA condenser equipped with a swing-out polarizer lens element and iris diaphragm. A circular 150 mm stage rotates 360 degrees continuously on ball bearings, graduated to 1 degree with a nonius vernier reading down to 6 arc-minutes for precise crystallographic alignment. The intermediate polarizing slider tube houses a focusable Bertrand lens and test wave plates, including a quartz wedge and mica retardation plate. The 7.5 kg cast frame (260 x 200 x 460 mm) operates on universal 100-240V AC power with coaxial coarse and fine focus knobs graduated to 2-micron increments.

Key Features of Kern OPM 181 Trinocular Polarizing Microscope

An educational and research transmitted-light polarizing compound microscope featuring stress-free Infinity Plan optics and an integrated vertical camera channel. Combines 40x to 400x magnification with a 150 mm rotating vernier stage, Abbe 1.25 NA condenser, Bertrand lens slider, and warm 20W halogen lighting.

• Stress-free Infinity Plan achromatic objectives: 4x, 10x, and spring-loaded 40x
• Circular 150 mm stage with 360-degree rotation, 1-degree scale, and 6 arc-minute vernier
• Integrated Bertrand lens slider block for orthoscopic and conoscopic crystal analysis
• Sub-stage transmitted 6V/20W halogen light source with continuous analog rotary dimmer
• Dedicated vertical photo tube port with internal beam splitter for digital camera archiving
• Height-adjustable Abbe 1.25 NA condenser equipped with swing-out polarizer and iris diaphragm
• Coaxial coarse and fine focus drive with calibrated 2-micrometer fine division markings
• Includes quartz wedge plate, mica quarter-wave plate, and crosshair reticle eyepiece

Stress-Free Infinity Plan Optics & Transmitted Polarization

Standard glass objectives contain internal cooling stresses that produce false birefringence under crossed polars. The stress-free Infinity Plan lenses on the OPM 181 eliminate residual lens strain, delivering pure black extinction so students can identify anisotropic minerals using the Michel-Levy interference chart. The 20W halogen lamp provides a warm, high-CRI continuous spectrum that brings out true pleochroism and natural mineral absorption colors across thin petrographic sections.

Conoscopic Bertrand Analysis & 360-Degree Vernier Stage

Swapping between standard orthoscopic mineral checks and conoscopic interference figures takes seconds: slide the centerable Bertrand lens into the optical corridor to inspect isogyres and optic signs directly through the crosshair eyepiece. The 150 mm circular stage rotates smoothly on internal guide bearings, letting operators track extinction positions accurately down to 6 arc-minutes before securing the centerable alignment screws.

• Integrated Bertrand lens provides instant toggling between orthoscopic and conoscopic views
• Precision 6 arc-minute vernier stage enables accurate crystal extinction angle calculations
• Reversed nosepiece with centerable ports maintains perfect target alignment during rotation

Kern & Sohn Three-Year Laboratory Warranty

Kern & Sohn covers the OPM 181 with a comprehensive three-year factory warranty covering optical elements, stand castings, and mechanical stage bearings, backed by two years on electrical halogen circuitry. The complete package contains the OPM 181 polarization stand, three stress-free Infinity Plan objectives, pair of HWF 10x/20 mm eyepieces, Bertrand lens slider block, quartz wedge plate, mica plate, power cable, dust cover, and manual.