sensortoolkit.qc

The sensortoolkit.qc subpackage contains various modules for quality control (QC) methods, including the identification and removal of duplicated timestamp entries, downsampling of irregularly spaced data, invalidation of data points, detection and removal of persistent or constant values, and the method of cleaning A and B channel data for PurpleAir PA-II measurements developed by Barkjohn et al. 2021 1.

Note

U.S. EPA’s Performance Targets Reports for air sensors measuring fine particulate matter or ozone outline protocols for testing and evaluating air sensors that aim to reflect “out-of-the-box” performance. As such, these documents do not make recommendations about quality control measures that testers may wish to apply to sensor data.

Modules in the sensortoolkit.qc sub-package should be considered an exploratory supplement to the data analysis methods recommended by EPA for evaluating air sensor performance.

Clicking on each module below will open a page with a detailed description and list of functions included within the module.

sensortoolkit.qc._duplicate_removal

This module contains a method for identifiying and removing duplicated timestamp entries in datasets.

sensortoolkit.qc._interval_downsampling

This module contains methods for applying downsampling methods to convert timeseries datasets at unevenly spaced sampling intervals to a uniform, evenly spaced interval (the downsampling interval).

sensortoolkit.qc._invalidate

This module contains a method for invalidating (set null or empty) a period of data recorded at consecutive timestamps for a specified time frame and parameter.

sensortoolkit.qc._outlier_detection

This module contains a method for detecting potential outliers in sensor datasets by computing the Cook's distance for measurements in 1-hour averaged sensor measurements relative to reference measurements.

sensortoolkit.qc._persistent_values

This module contains a method for flagging consecutive data values where the recorded value repeats multiple times.

sensortoolkit.qc._purpleair_abcleaning

This module contains a method for averaging the dual PMS5003 PM2.5 data channels for PurpleAir PA-II and PA-II-SD sensors.

Footnotes

1

Barkjohn, K. K., Gantt, B., and Clements, A. L.: Development and application of a United States-wide correction for PM2.5 data collected with the PurpleAir sensor, Atmos. Meas. Tech., 14, 4617–4637, https://doi.org/10.5194/amt-14-4617-2021, 2021.