Photomicrograph Scale Marker™
EMS Catalog #74802
The Photomicrograph Scale Marker has two functions
- The application of scale marks to photomicrographs.
- The measurement of the real-life size of structures from photomicrograph prints and negatives.
Description of Instrument
The instrument consists of an OUTER TRANSPARENT CASE and an INNER SLIDE on which is printed a series of SCALES.
There are FOUR SCALE LINES for producing SCALE MARKS of 10µm, 1µm, 0.1µm (100µm) and 10nm (100A) respecitively. Each of these scale lines can be used for the production of other sizes of scale marks (see below).
The figures on each of the scale lines represent the PHOTOMICROGRAPH MAGNIFICATION IN THOUSANDS. For example: on the u\10µm scale line the figure 2 represents x2,000 and the figure .7 represents x700; on the .1µm scale line the figure 200 represents x200,000 etc...
Along the top edge of the SLIDE is a standard MILLIMETER SCALE.
Application of Scale Marks
- Select desired scale mark- 10µm, 1µm, 0.1µm (100nm) or 10nm (100Å).
- Pull out slide until edge of outer case is alligned with the photomicrograph magnification on the appropriate scale line.
- Lay the instrument on the photomicrograph and, using a fine drawing pen, draw a line between the open arms of the instrument at the ARROW.
To apply a 10µm scale mark to a photomicrograph of x 3,000:
- Pull out slide until edge of outer case is alligned with the figure "3" on the 10µm scale line.
- The instrument will then be set to produce a 10µm scale mark.
Each of the four scale lines can be used for the production of any desired size of scale mark.
For example, to apply a 5µm scale mark, use the 10µm scale line and set the instrument at HALF the photomicrograph magnification. To apply a 0.5µm scale mark, use the 1µm scale line and set the instrument at HALF the photomicrograph magnification.
To Calculate The Setting For Any Size Of Scale Mark, Other Than The Four Printed On The Instrument, Use The Following Formula:
Desired scale mark/scale line used X magnification of photomicrograph
You wish to apply a 5µm scale mark to a photomicrograph of x 10,000.
Using the 10µm scale line the calculation reads:
5/10 X 10,000 = 5,000
Set the slide at x 5,000 on the 10µm scale line and the instrument is set to produce a 5µm scale mark.
You wish to apply a 25µm scale mark to a photomicrograph of x 600.
Using the 1µm scale line the calculation reads:
25/1 X 600 = 15,000
Set the slide at x 15,000 on the 1µm scale line and the instrument is set to produce a 25µm scale mark.
When the instrument is being used frequently for the application of scale marks to photomicrographs of less than x1,000, a 100µm scale mark may be the one most often required.
For this purpose, the 10µm scale line can be used as a 100µm scale line by considering the figures on the scale to represent the PHOTOMICROGRAPH MAGNIFICATION IN HUNDREDS (Instead of thousands). For example, the figure "6" would represent x 600 and the figure ".2" would represent x20.
Measurement of the Real-Life Size of Structures
For measuring the real-life size of structures from photomicrograph prints or negatives, the instrument is used in the same fashion as calipers.
Depending on the unit of measurement desired, different scale lines are used in the following procedure:
- To obtain a reading in µm use the 1µm scale line.
- To obtain a reading in nm use the 10nm scale line.
- To obtain a reading in A use the 100Å scale line.
- Pull open the slide until the space between the open arms of the instrument corresponds with the dimension of the structure being measured.
- Read the magnification indicated by the edge of the outer case on the appropriate scale line.
- Apply the following formula:
Size Of Structure = magnification reading / photomicrograph mag X scale unit selected
What is the real-=life size, in µm, of a structure which measures 22mm in a photomicrograph of x75,000?
In this case the desired unit of measurement is µm, therefore a reading is taken on the 1um scale line.
- Pull open the slide to the size of the structure. In this example the arms of the instrument would be opened 22mm.
- Read the magnification indicated on the 1µm scale line ... x22,000.
- Apply the formula:
Size Of Structure = 22,000 / 75,000 X 1µm = 0.29µm
What is the real-life size, in the nm of a structure which measures 2cm in a photomicrograph of x1000,000?
- Using the 100nm scale line, apply the formula:
Size Of Structure = 200,000 / 100,000 X 100nm = 100nm
What is the real-life size, in µm, of a structure which measures 4cm in a photomicrograph of x600?
- Using the 1µm scale line, apply the formula:
Size Of Structure = 40,000 / 600 X 1µm = 66.67µm
Units Of Measurement
µm = micrometer; nm = nanometer; Å = Angstrom Units
1 mm = 1,000µm; 1µm = 10,000A; 1nm = 10Å
Care of your Photomicrograph Scale Marker™
To clean the surface use an Ammonia-Based glass cleaning solution or Warm Water and Detergent. Polish with a soft cloth or tissue.
NEVER attempt to remove ink, or other stains, with a solvent such as acetone which may damage the surface.
When not in use always store the instrument in the protective pouch. Do not expose in extreme heat or leave in direct sunlight.
Eventually the outer case of the instrument may become scratched. Although this will not affect the smooth operation of the instrument, the case may be polished using any good quality vinyl polish.