Novel procedure for measuring the response time of aquatic sensors

Abstract:

Aquatic sensors (e.g. oxygen, sulfide, pH, or temperature sensors) are crucial for biogeochemical and ecological studies. The quality of data obtained by these sensors must be sufficient for desired applications. Sensor response time and therefore possible obtainable measuring frequency by the sensors are of central importance for selecting the most suitable sensors. Many applications such as benthic flux measurements, photosynthesis studies, and autonomous instruments require fast responding sensors with minimal measurement-error margins. It is essential to test the sensors in conditions similar to the environment that they will be deployed in. Here we present a method for reproducible response time measurements of aquatic sensors in field-like conditions. We also demonstrate procedures to examine the quality of data obtained by these sensors. We used our novel device to quantify the response times of oxygen sensors. We also deployed three identical collocated oxygen sensors in the Wakulla River, FL to test our quality-control procedures for data obtained from aquatic sensors. The response time measurement method was successfully used to quantify the response times of oxygen sensors with minimum errors and our field experiments could indicate the type (i.e. environmental or sensor related) and relative magnitude of errors in the measurements.