6/27/97

Can anyone suggest what to use as a length standard with a 100x

objective? I intend to print out an image of this standard when I print

images of samples, in order to determine final magnification. I am a little

concerned with the use of my micrometer slide (10 microns between

graduations) because the width of the individual lines is significant

compared to the distance being measured between lines. Also there is

no tolerance stated for the separation between the lines. I can think of

using calibrated latex beads suspended in water, but the refractive index

difference between latex and the aqueous medium (or air) causes a lot of

problems. Are there other standards I can use?

Thanks

Richard

Richard_Thrift@Depotech.com

traceable stage micrometers, certified to tenths of a micron.

Measurements are from centers of the lines. They're not cheap.

If you want to do your own certification, start with some regular fine

grid, perhaps a dime store holograph, measure it against some standard

you trust, and figure out the spacing.

corwinl@pt.cyanamid.com

improved if many spaces/lines and are included. A stage micrometer could be

used to establish the magnification and for a given lens combination that

figure would be "permanent". For some uses it could be most useful to then

establish the length of the negative in micrometers and use that as a

standard, but some people would prefer large latex spheres incorporated

with the specimens. For low power SEM and reflected LM there is a 0.01mm

graduated scale available for calibration of those instruments (See Pelco

or ProSciTech).

Jim Darley

ProSciTech Microscopy PLUS

PO Box 111, Thuringowa QLD 4817 Australia

Phone +61 77 740 370 Fax: +61 77 892 313

Great microscopy catalogue, 350+ Links, MSDS

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