Kyle, My response would be ".08 inch" minimum type size for the letter height in the laser label." per the Informative Annex B of ANSI Z535.4.
RATIONALE/BASIS: Section 4.7.1 of the American National Standard Z136.1-1993, "Safe Use of Lasers" states "Design of Signs. Sign dimensions, letter size and color, etc., shall be in accordance with American National Standard Specification for Accident Prevention Signs, ANSI Z535 Series (latest revision thereof). Figures 1a and 1b show sample signs for Class 2, Class 3a, Class 3b and Class 4 laser or laser systems." ANSI Z535.4-1998 "Product Safety Signs and Labels" has a section in Informative Annex B.3.2.13 addressing 'minimum letter height calculations'. "B3.2.13 Minimum letter height calculations. Type size is defined in "points," a term that was used to describe the space required for lead type characters. Point sizes measure from the top of the capital letters to the bottom of the lower case letters with descenders (e.g., the bottom of the letter "g" or "j" etc.). One point equals 0.01384 inches, or approximately 1/72 of an inch. Although type faces vary slightly, a practical guide for defining type size is based on using the capital letter "H" for measurement purposes. Since the character "H" has no descender, it is possible to use a conversion factor of 0.01 inches - 1 point of type size. Thus, 12 point type yields a capital "H" approximately 0.12 inches high. For metric purposes, use a conversion factor of 3.9 points = 1 mm of height for a capital "H." Recommended Letter Heights For Favorable Reading Conditions: 2 Feet or Less: Viewing Distance (in.)/150 >2 To 20 Feet: Viewing Distance ((ft.-2) X (.03)) +.16 Over 20 Feet: Viewing Distance (ft.)/28.6 Recommended Letter Heights For Unfavorable Reading Conditions (All Distances): Viewing Distance (ft.)X 0.84 Table - Examples of word message letter heights and minimum safe viewing distances. (Note: Only the first row is reflected below). Minimum Safe Viewing Distance - 1 Foot or less Minimum Letter Height for Favorable Reading Conditions - .08 inches Recommended Letter Height for Favorable Reading Conditions - .08 inches Recommended Letter Height for Unfavorable Reading Conditions - .084 inches (Note: Only the first row is reflected above). *.08 inch type is the suggested minimum type size for use on product safety signs." Regards. Tin In a message dated 10/1/99 11:43:04 AM Pacific Daylight Time, kyle.eh...@lsil.com writes: << Greetings, We have been lucky in the past, but with the real estate crunch that comes with smaller products, its getting more difficult to find space to apply a warning label. For example, a 'Class 1 Laser Product'. Just how tiny can the text/graphics in a label be and still comply? Kyle >> --------- This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
