USP a21
Green Tea
ASTM A21-94(1999)
Standard Specification for Carbon Steel Axles, Non-Heat-Treated and Heat-Treated, for Railway Use (Withdrawn 2003)
UNE-EN 60061-1/A21:1999
LAMP CAPS AND HOLDERS TOGETHER WITH GAUGES FOR THE CONTROL OF INTERCHANGEABILITY AND SAFETY. PART 1: LAMP CAPS
AS A21-1964
Specification for burnt clay and shale building bricks
AS A21-1934
Specification for building bricks
AWWA C110/A21.10-21
Ductile-Iron and Gray-Iron Fittings
AWWA C150/A21.50-21
Thickness Design of Ductile-Iron Pipe
KS B ISO 8038-1-2006(2021)
Optics and optical instruments — Microscopes — Screw threads for objectives and related nosepieces —Part 1: Screw thread type RMS(4/5 in×1/36 in)
KS B ISO 8038-2-2006(2021)
Optics and optical instruments — Microscopes — Screw threads for objectives and related nosepieces —Part 2: Screw thread type M25 × 0.75 mm
KS B ISO 8040-2006(2021)
Optics and photonics — Microscopes —Dimensions of tube slide and tube slot connections
KS B ISO 8424-2016(2021)
Raw optical glass-Resistance to attack by aqueous acidic solutions at 25 ℃-Test method and classification
KS B ISO 8478-2006(2021)
Optics and photonics — Microscopes —Dimensions of tube slide and tube slot connections
KS B ISO 8576-2006(2021)
Optics and optical instruments — Microscopes —Reference system of polarized light microscopy
KS B ISO 8600-3-2006(2021)
Optics and optical instruments — Medical endoscopes and endoscopic accessories — Part 3: Determination of field of view and direction of view of endoscopes with optics
KS B ISO 9211-3-2016(2021)
Optics and optical instruments-Optical coatings-Part 3:Environmental durability
KS B ISO 9211-4-2016(2021)
Optics and optical instruments-Optical coatings-Part 4:Specific test methods
KS B ISO 9334-2016(2021)
Optics and optical instruments-Optical transfer function-Definitions and mathematical relationships
KS B ISO 9335-2016(2021)
Optics and optical instruments-Optical transfer function-Principles and procedures of measurement
KS B ISO 9336-1-2001(2021)
Optics and optical instruments-Optical transfer function-Application-Part 1:Interchangeable lenses for 35 mm still cameras
KS B ISO 9336-3-2001(2021)
Optics and optical instruments-Optical transfer function-Application-Part 3:Telescopes