There are two zip files included with this adjunct. Each zip file includes a Dynamic Link Library (DLL) file and an Excel file. The Dynamic Link Library (DLL) file contains the method for calculating the calculated methane number (MN_C) as defined by ASTM D8221, Standard Practice for Determining the Calculated Methane Number (MN_C) of Gaseous Fuels Used in Internal Combustion Engines. This file can be used within Excel software and also Graphical User Interface programs that could be developed by a User to calculate the MN_Cvalue defined by ASTM D8221, Standard Practice for Determining the Calculated Methane Number (MN_C) of Gaseous Fuels Used in Internal Combustion Engines. It may also be used within industry (e.g., instrumentation suppliers) for instrument I/O calculations. The DLL file is compatible with 32-bit or 64-bit Microsoft Excel.

2) The Excel file was created by ASTM D03.03, WK54121 using the DLL file (1) and an Excel VBA macro. Each Excel file is supported by either a 32-bit or 64-bit platform. The Excel file can provide MN_C values for single or multiple gas samples. The Excel file also provides the following features: error messages, conversions from mol % or mass % to vol %, a sample normalization feature, and a “Readme Worksheet” that provides user instructions. The file has been “locked” and worksheet protected so it works without the potential for modification. User “documentation” is provided in Annex A1.1 Microsoft Excel program and Annex A1.2 Microsoft Excel VBA Macro of the standard practice.