Onsite measurement is necessary to preserve sample integrity and ensure data accuracy for the following field measurements: water temperature, dissolved-oxygen (DO) concentration, specific electrical conductance (SC), pH, and reduction-oxidation potential (redox/ORP).
A variety of single-parameter and multiparameter field-measurement instruments are available that use various technologies to measure the same water property and that require differing calibration, maintenance, and measurement methods.
|YSI Multiparameter Datalogging Sondes|
Multiparameter instruments that contain sensors (each specific to the measurement of a given physical, chemical, or biological property) that are bundled in a single housing (a sonde) and deployed in environmental waters.
Advantages of Multiparameter Sondes:
|Portable Turbidity Meters|
Turbidity, which can make water appear cloudy or muddy, is caused by the presence of suspended and dissolved matter, such as clay, silt, finely divided organic matter, plankton and other microscopic organisms, organic acids, and dyes. The color of water, whether resulting from dissolved compounds or suspended particles, can affect a turbidity measurement.
The following are examples of the uses for turbidity data:
|Seametrics Water Quality Sensors|
Often the changes in water measurements are more important than the actual measured values. Depending on the manufacturer, some instruments can store instantaneous or continuous measurements to internal or external memory in a format compatible with a hand-held display, personal digital assistant (PDA), or laptop computer.
Hach DR 900 Handheld Colorimeter
The hand-held DR 900 allows quick and easy access to your most-used testing methods. This colorimeter is waterproof, dustproof and field durable. With an intuitive user interface, easy data transfer abilities, and the ability to test up to 90 of the most commonly tested water methods, the DR 900 makes water testing in harsh field environments a little less challenging.
|Calibration Buffers, Standards, Reagents and Cleaners|
Reference materials whose properties have been established so that it can provide a level of performance verification. For field measurements, examples are pH buffers, specific conductivity standards, chemical reagents, turbidity standards and oxidation reduction potential standards.
Field instrumentation require supplies for the actual collection process as well as quality control activities and crucial operational maintenance.