2195748

Information

• Patent Grant
• 2195748

• References
• Source

• Patent Number

  2,195,748

• Date Filed

  Not available

• Date Issued

  Tuesday, April 2, 1940
  85 years ago

• CPC

  • G01J1/40 - using limit or visibility or extinction effect

• US Classifications

  • 356 - Optics: measuring and testing