RADIATION SPECIFICATIONS FOR 1540 LIGHT TABLE ILLUMINATION SOURCES

• Document Type: CREST
• Collection: NGA Records (Formerly NIMA)
• Document Number (FOIA) /ESDN (CREST): CIA-RDP78B05171A000600020035-4
• Release Decision: RIPPUB
• Original Classification: S
• Document Page Count: 1
• Document Creation Date: December 28, 2016
• Document Release Date: April 10, 2003
• Sequence Number: 35
• Publication Date: November 4, 1969
• Content Type: MF

Approved For Release 201 RlA-RDP78B05W1A000600020035-4
MC/TSSG/RED-1907-69
4 November 1969
AEMORANDUM TO: Chief, Special Contracting & Procurement Staff, TSSG
SUBJECT . Radiation Specifications for 1540 Light Table Illumination
Sources
1. In a letter dated 20 October 1969, the requested 2 X1
clarification of Paragraph 3.1.1.2 of the 24 Ju
ly 1959 Development Objectives
for the Split-Format 1540 Light Table and Mount for Various Microstereoscopes.
2. The specification in question related to radiation of the phosphor
employed in the light sources for the table. The development objectives
required that radiation be limited to specified maxima below 380 nanometers
and above 750 nanometers. questioned whether the intent of the
specification required mepsurement of radiation throughout the entire electro-
magnetic spectrum below 380 nanometers and above 750 nanometers, or if measure-
ment could be restricted to bands adjacent to the visible spectrum.
3. Investigation indicates that the last two sentences of Paragraph 3.1.1.2
of the subject development objectives should be changed to read:
'`Radiation in he range of 200 to 380 manometers will be limited to
o.5 micro watts/cm . Radiation in the range of 750 to 1,500 nanometers
will be limited to 0.025 watts/cm2.tt
4. Paragraph 3.1.1.2 also specifies that equivalent color temperature of
the light sources must be 30000K to 5000?K. A range of color temperatures of
6000?K to 6500?K is more appropriate for the viewing of color film, and at the
same time is satisfactory for viewing black and white film. Both the 0 25X1
have indicated that changing the range of
color temperature to 6000?K to 6500?K would not present a problem. NPIC
personnel have stated the desirability of making the light sources compatible
with color viewing. Therefore, the first sentence of Paragraph 3.1.1.2 of
the subject development objectives should be changed to read:
"Broadband white illumination will be required with an equivalent
color temperature between 6000?K to 6500?K at all luminance levels.
25X1
Distribution:
Original. - Addressee
Chief, esearc Engineering Division,
TSSG
1 - A 3OJW&8 F/d telease 200319_511J.:
~2 - NPIC/TSSG/SDB 444W
Declass Review by
71A0d U UD[35-4