Model 179         "Polarizing Microscope"

This highly engineered polarizing microscope utilizes superb mechanics and very rugged construction, at a cost far below similar models in its category. National’s petragraphic microscope can be used as a standard bright field or Polarizing microscope, and is best used for examination of geology, mineralogy, and other scientific samples requiring polarized light.

OPTICAL SYSTEM

• Wide field 10x /18mm eyepieces with built in cross line reticle  

• 45° inclined monocular viewing head rotates 360° for easy sharing by more than one student

• DIN standard 4x (0.10 N.A.), 10x (0.25 N.A.), 40xR (0.65 N.A.) All are achromatic, parfocalled, parcentered and color-coded.

• Built in Bertrand lens, mounted in slide in/out mount

• Built in Analyzer (polarizer lens) rotates 0 to 90 degrees with 1 degree graduations.

• Built in 3-position slider bar with, ¼ wave and full wave plates and one open aperture.

• Built in swing-out Polarizer lens.

• Objective turret, ball bearing mounted for smooth, precise changes in magnification.

ILLUMINATION

• Built-in 12-volt 20-watt halogen illumination with variable rheostat control.

• Base mounted on/off switch, 120 volts AC, 50/60 Hz operation, with heavy-duty six-foot three-wire grounded electrical “grabber” clip plug.

• 0.5A time delay fuse.

FOCUSING

• Separate low position coarse and fine focusing controls.
• Stage moves up or down, eyepiece and body remain fixed.
• Slip clutch prevents damage to focusing system.
• Tension adjustment eliminates stage drift.
• Safety rack stop prevents damage to slides and objective lenses.

STAGE

• Large 135mm diameter stage rotates 360 degrees with one-degree graduations marked on stage and venire scale reading 0.1 degree.  Also includes two stage clips
• 1.25 N.A. Abbe condenser with spiral focusing mount, iris diaphragm, swing-out filter holder, blue filter supplied.

FRAME

• Rugged cast metal, gray enamel finish.
• Base dimensions: 175mm x 210mm (7 in. x 8-1/4 in)
• Height 382mm (15 ¼ in.).
• Net weight 4.29 kgs (9.45 lbs)

PACKING

• Molded Styrofoam container with instruction brochure and vinyl dustcover.
• Individual:  Ship wt. 7.33 kgs (15 lbs), Dimensions 559x406x254mm (22x16x10 in.)

WARRANTY

• Lifetime limited warranty, excluding bulb, cord, fuse, and accessory mechanical stage.