This converter imports data files from the Windows-based OMNIC software.  Note that there are now 2 versions of this converter. 

NIC_OMNC Old Version for all products
The older version continues to support GRAMS.  The default file extension is assumed to be *.SPA.  Note that the OMNIC software has provisions for many more unit types than are available in GRAMS.  Therefore, units such as %Transmission will import as Transmittance, %Reflectance as Reflectance, etc.  Export is supported but is only reliable with FT-IR data files.  Certain information is lost on export.  These include the date and time and the resolution.  Also only the unit types supported by both GRAMS and OMNIC are used on export.  All others are set to Arbitrary.  The supported units include: Y Types - Absorbance, Transmittance, Kubelka-Munk, Reflectance, (GRAMS/AI only: Single Beam, Log(1/R)), and Volts.  X Types - Wavenumber, Nanometers, Micrometers (Microns) and Hertz.

GRAMS Special Instructions for the Old Version
This converter uses the GRAMS Universal File Format when the data files are imported.  This structure carries certain instrument parameters in the DBLOG text at the end of the data file.  This information is stored in ASCII and can be viewed using the FILEINFO.AB program, accessed via Array Basic programs, or placed in views.  On export, this information is used to reconstruct some of the instrument parameter blocks in the OMNIC data file.  If this information is not present, or GRAMS data file was originally imported with Spectra Calc or Lab Calc, then the instrument parameters are set to zeros.  This will cause these values to appear as "Unknown" in the OMNIC software; however, the actual spectral data will be correct.  The converter does not allow export of GRAMS/AI XY or XYXY type files.

NIC_OMNC New Version
The new version adds support for *.SRS series multi-files and for better tracking of the log text information in the original *.SPA files.  This change now requires the converter to store SPC files in a GRAMS file format only. These SPC file cannot be read by Lab/Spectra Calc. 

The new version of the converter is capable of recognizing two Thermo Nicolet OMNIC file types:

• *.SRS - Series (multi) files
• *.SPA - IR Spectrum, contiguous, Y-Only (single) files

NOTE: The new version of this converter requires GRAMSC32.EXE V1.11 or higher! If used with V1.10 or older, the default file extensions will only show *.SPA (not *.SPA & *.SRS).  On export the *.SPA extension is always assumed.

On import, depending on Thermo Nicolet OMNIC file type, the following files are created:

• If the source file is a Series (*.SRS) file then *.SPC and *.CGM files are created, where *.SPC is a Multifile with Uneven Z axis values and has a Log Text file section according to Universal File Format specification; *.CGM is a Chromatogram type Single file with Array of FP X values preceding Y data.  Both files are saved in GRAMS format only.
• If the source file is IR Spectrum file then *.SPC Single file with a Log Text file section according to Universal File Format specification in GRAMS format is created.

On export, only the GRAMS Single File type is supported.  Range of valid GRAMS source files includes single files in old 4D and new 4B format with or without Log Text section.  Export of GRAMS files with SP Y-Data, XYY data and XYXY data is not supported.  Created output file is in Thermo Nicolet OMNIC IR Spectrum contiguous Y-Data file type (*.SPA).

Known Limitations of New Version

• On export, at least 2 (Main Data Header and Y-Data) and at most 3 (Main Data Header, Y-Data and Bench Info) out of variable number of .SPA file sections are reconstructed in addition to Pre Header and Index sections which are always present depending on availability of Log Text section in the source file. 
• Resolution text will be lost after first export due to unavailability of fields in .SPC header and labels in .SPC Universal Data Text Section corresponding to data fields in OMNIC file from which resolution is calculated on import.
• Date/Time conversion is not supported on neither import nor export.
• Present product does not differentiate between OMNIC X/Y axis units such as: Absorbance and %Absorbance,Transmittance and %Transmittance.  On import default is Absorbance and Transmittance.  On export default is % Absorbance, % Transmittance.
• On import when the source file is in OMNIC Series file format (*.SRS) only data blocks representing Multifile Y-Data are recognized and converted.  Single Y-Data part is omitted due to its unknown origin.
  

OMNIC software can also directly save data files in J-CAMP format.  Use the File / Save As... command in the OMNIC main menu and select JCAMP (.JDX) as the file type.  These files can be imported using the J-CAMP converter.  OMNIC can also save files in the PC-IR format by selecting the PC-IR (*.IRD) file type.  These files are compatible with the NIC_PCIR converter.

This converter can also read data files from the ASI Applied Systems/Mettler Toledo ReactIR system.