About VOCDat
Since the mid-1990s, the U.S. EPA has sponsored the development and enhancement of VOCDat software. VOCDat is a Windows-based program that imports and displays air pollutant data collected as part of the air toxics, particulate matter, and ozone precursor monitoring networks. Users then can perform quality control tasks on the data (e.g., apply screening criteria, visually inspect data), perform exploratory data analysis, and prepare data sets ready to import to the EPA's Air Quality System (AQS). One of the goals behind the development of this software was to enable the states to rapidly validate and release their data.
VOCDat Features
Imports and exports AQS R2 format. VOCDat can also import and export AMP370 (old AIRS) format data.
Imports flexible format ASCII files. This feature assists the user in handling data obtained from more than one laboratory and the various file formats in use.
Imports other special types of data. For example, VOCDat imports pre-2003 versions of Perkin Elmer Turbochrome (automatic gas chromatograph) and more recent Totalchrome format data employed at some PAMS sites.
Provides export formats suitable for other software. To provide the user with more data analysis choices, VOCDat export options include formats suitable for use in spreadsheet and statistical software.
Allows on-screen editing of data quality control (QC) codes. QC codes are then translated into user-selected null data codes needed for AQS. The quality control (QC) codes may be changed for individual data points as well as for the entire sample on all plots. VOCDat keeps a log of changes including user-input comments.
Performs QC screening checks. The screening checks are designed to provide the user with samples that have potential validity problems. Screening checks are customizable to accommodate the differences in pollutant concentrations and characteristics among sites. VOCDat can also compute summary statistics of the pollutant concentrations.
Prepares graphical displays of time series, scatter, and fingerprint plots.
The concentrations of the pollutants may be displayed using time series, scatter,
and fingerprint plots. Time series plots show the concentrations of species over a
specified time period and are useful in showing the temporal behavior. Using
scatter plots, the relationship between species may be investigated. Fingerprint
plots show the concentration of each species in a sample and help to identify
unique characteristics of the samples.
Allows the user to convert units. The concentrations of the gaseous pollutants may be converted among ppb, ppbC, and μg/m3 units.
