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Frequently Asked Questions & Answers (FAQs)

Oil and gas industrial refinery.

1. Can I evaluate your SimDis Expert or Hydrocarbon Expert software to determine if I want to purchase it?

Yes you can. Click on the appropriate link below to download the software you are interested in evaluating.

For SimDis Expert 

For Hydrocarbon Expert

For Sulfur Expert

2. If I download your software for evaluation, how long will I be able to use it?

We built a ‘counter’ into the evaluation software. We normally set it to allow the user to process up to 100 GC data files.

3. Can the software evaluation ‘counter’ be increased?

It depends. We assess each request individually. If you’re interested in increasing your ‘counter’, please send your request to

4. What capabilities are in the SimDis Expert Advanced that aren’t included in the SimDis Expert Lite software?

The SimDis Expert Advanced features the following capabilities:

  • The ability to use DHA data to correct ‘front end’ boiling point data produced by ASTM D7169 or D6352. The technique is commonly referred to as ‘merging’. It is referred to as ‘Merge Expert’ in the SimDis Expert.
  • Multiple chromatograms can be overlaid for comparative purposes. The SimDis Expert Lite only allows 2.
  • You can compare multiple stored reports on paper or on-screen to a sample analysis.
  • You can generate multiple cut point tables. 
  • The SimDis Expert Advanced allows you to combine multiple reports in a single .pdf file.
  • You can customize reports.
  • The SimDis Expert Advanced can be upgraded to support non-FID detectors such as SCD, FPD, AED, NPD or MSD.
  • You can upgrade it to perform aromatics and saturates analysis using FID and MSD.

5. I lost or misplaced the (USB) security key required to run your software. What can I do?

You should contact Please note, it would be very helpful if you could find out when the software license associated with the missing USB security key was originally purchased and by whom. You should include this information in your email message.

6. What is ‘Merge Expert’?

Merge Expert is a feature in SimDis Expert Advanced software. It allows the user to ‘merge’ high resolution chromatography data file from a DHA GC (detailed hydrocarbon analysis) data to ‘correct’ the front-end boiling point data (curve, cut point table) produced running ASTM D7169 or ASTM D6352.

7. Why might I need to ‘merge’ simulated distillation data with DHA data?

Because thin film capillary columns are used in high temperature simulated distillation test methods (ex. ASTM D7169 and D6352), the C4 to C8 region of the chromatogram will not be completely separated in the presence of a large amount of carbon disulfide used to prepare the samples. As a result, this yields incorrect boiling point distribution during the peak elution interval.

This affects the results in two ways:

  1. First, the carbon disulfide peak is very large and elutes in the same region as the C4 to C8 peaks in the sample itself. This makes it very difficult if not impossible for the GC software used to acquire the detector signal  to assign peak areas to the C4 to C8 peaks. 
  2. Second, as carbon disulfide elutes from the column it negatively affects the response of the flame detector (‘quenching’) making quantitative analysis in the region unreliable. 

To get around this problem, a separate, higher resolution gas chromatograph (GC) analysis (detailed hydrocarbon analysis or DHA) of the light end portion of the sample can be ‘merged’ with the simulated distillation data. This process allows for a more accurate description of the boiling point curve in the interval in question. This is described in ASTM D7900 (Appendix X1).

If you or your company isn’t interested in the boiling point data in the C3 to C8 region then you probably don’t need to perform DHA front end merging.

8. Why should I upgrade to SDE 10?

SDE 10 supports Windows 10 and 11. Earlier versions of SimDis Expert and Hydrocarbon Expert do not.

Additionally, SDE 10 includes new features such as: 

  • Calculated molecular weight.
  • It allows baseline subtraction for retention time standards.
  • It can calculate cut points as Average Molecular Weight.
  • SDE 10 allows baseline subtraction for retention time standards. This improves peak integration for heavy paraffins. You no longer need to use the GC data system for baseline subtraction.
  • It contains a universal driver so signals can be loaded from any popular GC data system (ex. Agilent OpenLab, Chromeleon, ChromPerfect, DataApex).
  • SDE 10 features a redesigned method configuration dialog. It now shows the scope of the test method, chromatographic conditions, and related consumable items such as calibration standards.
  • The SimDis Expert will automatically ‘extract’ the GC data acquisition method name from the existing signal file. Users no longer need to remember the name of the acquisition method.

9. I currently use Agilent OpenLab GC Chemstation software. How can I set my system up so the GC data files are automatically processed by SimDis Expert or Hydrocarbon Expert?

You must set up your system so the GC data files produced are exported to SimDis Expert or Hydrocarbon Expert. Follow the procedure below:

  1. Go the file location on your PC c:\separationsystems\(SDE10 or HCE5)\ssdriver\support\agilent\ch2ssm
  2. Copy all the files
  3. Paste them into c:\program files(x86)\Agilent Technology\Chemstation\core
  4. Open OpenLAB GC Chemstation 
  5. Load the GC Method that will be used for Data Acquisition
  6. Go to Run Time Checklist
  7. Add or insert “macro sepsys_cvt.mac, go” in the Data Analysis Macro field.  This will create an SSM file at the end of each injection.

Note: The latest revision of the macros can be downloaded from SSI’s support portal:

10. When loading a signal in SimDis Expert 10, the parameter file the software tries to select is missing the last letter. As a result, it does not match the name of the data acquisition method. Why does this happen?

This is caused by a global configuration setting. The software can be configured to interpret the last letter of the acquisition method as the injection mode. For example, if the data acquisition method is GC1_D2887.M, then SimDis Expert 10 searches for a parameter file named GC1_D288.PRM

This is an old way to operate the software and used in older versions of SimDis Expert (9 and lower). However, this was retained in the current version of SimDis Expert (v10) to ensure backward compatibility. 

If you are using codes (ex. $T, $A, etc.) embedded in the sample name to identify the type of injection, then make sure SimDis Expert (v10) is configured as shown in the diagram below:

SimDis Expert (v10) configuration diagram.

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Contact Our GC Specialists for More Support

At Separation Systems, we also offer application, training, system revalidation, and a wide range of other services. If you need further support regarding our analyzers, feel free to contact us anytime. Give us a call today at +1-800-340-3302 for US or +1 850-932-1433 x11 Internationally.