Certificate Of Analysis

A Certificate of Analysis (COA) for a calibration gas is an official document issued by the gas manufacturer that certifies the composition, concentration, and traceability of the gas mixture contained in a specific cylinder.

The COA serves as proof that the calibration gas has been analyzed and verified to meet the stated specifications and is suitable for calibrating gas detection and analytical instruments.

A typical calibration gas COA includes:

• Cylinder serial number – Unique identification of the gas cylinder.
• Part number or product code – Identifies the gas mixture supplied.
• Gas composition – The gases contained in the mixture.
• Certified concentration – The exact concentration of each component (e.g., 25 ppm H₂S, 100 ppm CO, 18% O₂).
• Analytical tolerance or uncertainty – The accuracy of the certified concentration.
• Balance gas – The gas used to make up the remainder of the mixture (usually nitrogen or air).
• Manufacturing date – When the gas mixture was prepared.
• Expiration date – The date until which the certified values remain valid.
• Traceability information – Evidence that the mixture is traceable to recognized standards, such as those from National Institute of Standards and Technology.
• Quality assurance approval – Signature or approval from the manufacturer’s quality department.
• Certification statement – Confirmation that the mixture meets applicable specifications and quality standards.

Why is the COA important?

The COA is important because it:

• Verifies that the calibration gas concentration is accurate.
• Provides documentation for quality audits and regulatory compliance.
• Demonstrates traceability to recognized standards.
• Ensures confidence in instrument calibration results.
• Supports safety and quality management systems.

“A Certificate of Analysis (COA) is an official document that verifies the exact composition, concentration, accuracy, and traceability of the calibration gas contained in a specific cylinder. We are able to provide COA before you placed your order, as different lot have different COA. Each Lot of cylinder’s COA is unique.