The calibration gas used to calibrate BTU Analyzers can have a significant impact on your company's bottom line. Inaccurate BTU values of natural gas can add up to tens of thousands of dollars in lost revenue.

Matheson offers number of standard ranges to meet the requirements of ASTM methods outlined in the Gas Processors Association (GPA) Standards. Below is a table listing the Natural Gas Reference Materials and their standard Ranges as defined by the GPA. Should your requirements exceed the mixes listed please contact your Matheson Sales Engineer.

Matheson Gas Products has developed the most accurate, state-of-the-art BTU Calibrations standards in the industry. Matheson is the first and only supplier that has natural gas NTRMs, offering you direct traceability of IST measurement. We offer five grades of Natural Gas Reference Standards:

1. Maxitherm
2. Primary Grade
3. Unitherm
4. Gravimetric Grade
5. Certified Grade

Matheson proudly introduces MAXITHERM, the most advanced BTU calibration standard available today. If accurate, consistent BTU measurement is of the highest importance to you, you will appreciate Maxitherm's features:

• BTU calibration accuracy of ± 1%
• NIST NTRM Traceability
• High resolution Gravimetric Preparation
• Highest Grade raw materials available
• Blend Tolerance 1%
• Certification Accuracy 1%

Maxitherm is available in a number of minor components, concentrations and cylinder sizes. Please contact your local Matheson Sales Engineer for pricing and availability.

Matheson's primary grade natural gas standard is a precision blend designed for those users that do not require the precision of the Maxitherm product. Mixture specifications are patterned after Maxitherm, but are more lenient on the BTU accuracy. Primary Standard Natural Gas Standards offer:

• BTU calibration accuracy of ± 1-2 BTU
• Certification by NIST NTRM and Gravimetric Standards
• High resolution gravimetric preparation
• Highest grade raw material
• Very tight blending and analytical tolerances
• Cylinder to cylinder reproducibility of 1.5 BTU

Matheson can provide up to one hundred identical natural gas standards containing compounds lighter than n-hexane. Identical standards ensure consistency of instrument calibration for multiple analyzer applications. Unitherm blends offer the following specifications:

• ± 1-2 BTU Dual Certification
• NIST NTRM & Gravimetric Certifications
• Mixture Preparation with jumbo tubes and scales
• Batch homogeneity 0.7 BTU

Matheson's Gravimetric Natural Gas Standards offer BTU quality without the premium pricing of our Maxitherm. Our Gravimetric Grade's specifications are as follows:

• BTU calibration accuracy of ± 4%
• NIST NTRM Traceable Standard
• Gravimetric Preparation
• C₂-C₆ meet GPA Specifications, Methane exceeds GPA Specifications
• Blend Tolerance ± 2%
• Certification Accuracy ± 2%

Matheson's Certified Grade natural gas standards are engineered for less critical calibration requirements. Care is taken to insure that each standard meets and exceeds the requirements established for Certified Grade material. Our Certified Grade's specifications are as follows:

• No BTU Accuracy Provided ( ± 2% typical)
• Lab Standard Certification
• Gravimetric or Volumetric Preparation
• Meets GPA Specifications
• Blend Tolerance ± 5%
• Certification Accuracy ± 2%