SEMA Gases – Calibration Gas Solutions

What is the difference between calibration gas and span gas?

Calibration gas is a reference gas with a known concentration used to test or calibrate a gas detector or analyser. Span gas is the calibration gas used to set or verify the instrument’s response at a known concentration above zero.

What types of calibration gases do you supply?

SEMA offers single-gas and multi-gas mixtures for flammable gases, toxic gases, oxygen, carbon dioxide and other detector or analyser applications. Availability depends on the required concentration, balance gas and cylinder size.

What is the typical shelf life of a calibration gas cylinder?

Shelf life depends on the gas mixture, concentration and cylinder specification. The applicable expiry date is stated on the cylinder label and accompanying documentation.

Can you supply custom gas mixtures for specific applications?

Yes. Custom mixtures can be requested according to the required gas components, concentrations, balance gas and cylinder size. Please provide the gas detector or analyser model and the required mixture specification when requesting a quotation.

How should calibration gas cylinders be stored and handled?

Calibration gas cylinders should be stored upright and properly secured in a well-ventilated area, away from heat and ignition sources. The storage and use temperature should be maintained between −10°C and +50°C, unless otherwise specified in the documentation for the particular gas mixture or required by local regulations.

Are calibration gas cylinders supplied with documentation?

SEMA calibration gas mixtures are supplied with relevant product and traceability information. A Certificate of Analysis is available and includes the certified concentration, uncertainty, batch data and applicable traceability.

Why is a Certificate of Analysis important?

A Certificate of Analysis confirms the gas composition, uncertainty and traceability. SEMA certificates are issued in accordance with ISO 6141, while ISO 6142 and ISO 6143 may be used in the preparation and verification of gas mixtures.

Which regulator is required for a calibration gas cylinder?

The correct regulator depends on the cylinder valve, required flow rate and calibration method. Fixed-flow and demand-flow regulators are available for different applications.