USGS-OWQ: TM1-D5 Data Processing: Data Processing Procedures for Optical Nitrate Sensors
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Official Method Name
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Data Processing Procedures in Optical Techniques for the Determination of Nitrate in Environmental Waters |
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Current Revision
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Media
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WATER |
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Instrumentation
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UV-Fluorescence |
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Method Subcategory
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Inorganic |
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Method Source
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Citation
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Protocol
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USGS TM1-D5 - Optical Techniques for the Determination of Nitrate in Environmental Waters: Guidelines for Instrument Selection, Operation, Deployment, Maintenance, Quality Assurance, and Data Reporting |
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Brief Method Summary
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Data-processing procedures for continuous nitrate data follow existing USGS methods for continuous monitors described in Wagner and others (2006) and other related guidance. Continuous records undergo an initial evaluation, flagging of erroneous data, application of data corrections, and a final evaluation. Data are archived electronically in the National Water Information System (NWIS) database with project or site information following project and Science Center data-management and quality-assurance plans. New data received by way of telemetry or otherwise recently loaded into NWIS are viewed each day, and any obviously erroneous data are addressed. Data corrections are applied for fouling and drift on the basis of information collected during site visits. In addition, corrections for systematic errors due to matrix effects can also be applied. A final data evaluation includes a review of the record, review of the corrections, and any final revisions.
Uncorrected data from the optical sensors are valuable information that can be used for data-processing or for additional research or interpretation. Any raw data used for data-processing procedures are archived primarily in NWIS or in Science Center records, if NWIS is unable to store the necessary information. For UV nitrate sensors, this can include burst data, raw absorbance values at individual wavelengths (if reported), and instrument diagnostic data. |
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Scope and Application
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This section of USGS TM1-D5 covers data processing for optical nitrate sensor data and sections inlude:
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Applicable Concentration Range
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Interferences
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Quality Control Requirements
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Sample Handling
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Maximum Holding Time
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Relative Cost
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Unknown |
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Sample Preparation Methods
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