Help System   Source
Source Input Information

The Source Edit page is one of the four main editing pages for OBODM. All changes to the source type and locations are done on this single page. Previous versions of OBODM had multiple pages which have been incorporated into this single page.

All items and descriptions are nearly identical to the original OBODM program. This is to allow easy migration to OBODM2. The input fields have been grouped to best represent how they are associated.

There are a few steps that need to be followed. First, the Fuel and Pollutant types can be selected from the database, or entered directly. The database information is from the original OBODM data. The majority of that information was obtained from testing at the Dugway Proving grounds in Utah in the 1980s and 1990s using the Bang Box technique.

Each source location is added to the Source point table by copying an existing one and then modifying it. There must always be at least one source.

Depending on the type of source and the emission type, different options are available. These are shown in the lower colored box area.

If particle information is needed, click on the Particle radio button, and a special editing floating window will come up. See details about this window below.

For multiple source points data, a file can be loaded. The actual loading of the file is done in the Files - Load Source File command. This page only lists what files have been loaded, and allows the user to select the required file from the database. The file format is important and the following paragraph gives details. Note, data file option is only allowed if the meteorological (Met.) data is set to Hourly in the Met. option screen. When the hourly option is switched (between hourly and single on the Met. option screen) all hourly source data options are reset.

Source File Format

For open burn analysis, the burn amount can be based on hourly burns. This means, the burn amount can be set for each hour. Due to the large number of possible input data (8,760 for one year, 365x24) this information can be inputted with a text file.

Note, BOTH the meteorological and source files must have the EXACT number of entry. A source data file cannot be used with a corresponding meteorological input file.

The input file format is very simple. First, it is plain text (no compressed binary). There are four data types per record (group number, mass amount, heat content, and burn rate). Each data type must be separated by a space (FORTRAN free format).There is one record per line.

Note, unlike OBODM version 1.3, there is no user set formatting for the input file. If an old file is used, it must be edited to match the above format and include all four items in the order given.

The burn rate can only be changed with Quasi-continuous emission type. For Quasi-continuous the default rate is 300 g/sec. For instantaneous the default rate is 2.5 g/sec. The rate returns to the defualt each time the emission type is changed. For simplicity, the units match the database units, grams per second. This cannot be changed.

Particle Edit Screen

If particle size distribution is known, and needs to be included in the analysis, that information can be edited in the floating Particulate Data window. When it first opens, all fields are computed. The user can then edit them individually if needed.