3693021

Information

• Patent Grant
• 3693021

• References
• Source

• Patent Number

  3,693,021

• Date Filed

  Not available

• Date Issued

  Tuesday, September 19, 1972
  52 years ago

• CPC

  • G01N21/8916 - for testing photographic material

• US Classifications

  • 356 - Optics: measuring and testing
  • 250 - Radiant energy