Burettes PTFE Key Stopcock Class A - Schellbach Stripe

• Schellbach Stripe: A vertical white stripe with a central blue line fused to the back of the burette.
  • The "X" Effect: When viewed through the liquid, the meniscus causes the blue line to appear as two opposing triangles meeting at a point (forming an "X"). You read the volume exactly where the two points touch.
• PTFE Key Stopcock: Uses a self-lubricating, straight-bore PTFE plug.
  • Benefit: It is 100% grease-free, preventing contamination of your titrant and ensuring the stopcock never seizes.
• Class 'A' Accuracy: Provides the lowest possible margin of error (e.g., ±0.05 mL for a 50mL capacity).
• Batch Certificate: Each unit is tested and verified against ISO 385 standards, with a certificate included for your lab's quality compliance (ISO 9001, GLP).

• The Visual: The blue line appears to narrow into two opposing triangles or "arrow points".
• The Reading Point: The precise volume is read at the exact point where these two blue triangles meet, forming an "X" shape. 

• Parallax Removal: It forces your eye to be at the correct level; if you are looking from above or below, the "X" will not align perfectly with the graduation mark.
• Enhanced Contrast: The white background makes the meniscus of colorless or clear liquids much easier to see.
• Precision: By providing a single point of reference (the "X"), it allows for repeatable readings down to 0.01 mL in high-quality Class A burettes.

Specifications Table

Specifications

• Compliance: Conforms to ISO 385 Class B standards.
• Accuracy: Class 'A' Schellbach
• Certificate: Batch Certificate
• Material: High-grade Borosilicate 3.3 Glass, providing superior resistance to chemical corrosion and thermal shock.
• Graduations: Durable Blue (amber on request) enamel graduations.
• Stopcock Type: Straight Bore with a PTFE (Polytetrafluoroethylene)
• Brand: OMSONS
• Product of India