Klarmann Rulings Inc.

Counting Chambers

IMA Graticule KR 100

When ordering the IMA Graticule specify the diameter (in millimeters) of the graticule disc to fit your microscope eyepiece and the magnification factor (MF). The MF is unique for each microscope and 10x objective combination. Determining the correct MF value insures that the sizing circles will be exactly 10 and 25 microns+/-2% on your microscope. The MF value is calculated as follows:

1. Set up the microscope with all the attachments and lenses you will use during the IMA. The IMA requires a compound microscope with a 10x objective, two 10x eyepieces and episcopic (vertical) illuminator, IMPORTANT! To calculate a correct MF value the episcopic (vertical) illuminator must be installed along with the other attachments affecting the microscope tube length/magnification (anything placed between the objective and the eyepiece).

2. Insert a 100 division/10mm graticule scale into one eyepiece. Many microscopes are purchased with such a scale already installed.

3. Adjust the interpupillary distance.

4. Adjust the magnification to 100x by moving the 10x objective into place.

5. Turn on the microscope's illumination and focus the eyepiece so that the graticule lines are clear and sharp. Rotate the eyepiece diopter ring to focus, not the microscope focus knob.

6. Place a certified stage micrometer of 100 division/1mm on the microscope stage and focus the microscope on the graduated lines.

7. Adjust the microscope stage x & y controls to align the stage micrometer parallel with the eyepiece graticule scale at the zero division.

8. Record the largest number of whole eyepiece graticule scale divisions (GSD) per corresponding whole stage micrometer division (SMD). To make the measurement as accurate as possible a large part of each scale must be used. The ratio of eyepiece graticule scale divisions/stage micrometer divisions is the magnification factor (MF).

9. Examples

If there are 75 GSD per 80 SMD then MF = 0.938 or (75/80)
If there are 95 GSD per 92 SMD then MF = 1.032 or (95/92)


What and where to order:

IMA Graticule
Part No. KR 100
Specify graticule diameter & D value
Delivery 2-3 weeks

Klarmann Rulings Inc.

Toll Free: (800) 252-2401

             NH: (603) 424-2401

            Fax: (603) 424-0970

How many Millimeters (mm) in eyepiece equals 1mm on stage?

Counting Chamber IMA/USP
Print Window IMA/USP
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