G23 Thompson Graticule, 21mm
Specialist Designs
Thompson - G23, 21 mm
For counting particles in any of three areas of known size. The graticule is calibrated in the same manner as a normal eyepiece scale. The result is then used to calculate the area of any square.
- Thompson for dust analysis.
- 10 mm, 7 mm and 4 mm squares.
- Glass Sandwich.