We don't often think about oxygen in our day to day terrestrial lives. In fact, we take it for granted. We're just happy that 20.9% of our air is made up of oxygen. We also seem to take it for granted in regards to our aquatic friends. Oxygen, known as dissolved oxygen, in water is used by all aquatic life.
Some species require a different range of dissolved oxygen levels than others to survive and even thrive.
When it comes to aquatic life, DO is often the limiting factor in regards to reproduction, growth and healthy survival rates. In order to understand dissolved oxygen levels in water, scientists, aquaculturists, wastewater operators, lab personnel, environmentalists, and natural resources managers have used DO meters since the advent of dissolved oxygen technology.
Well, since then, DO meters and sensor technologies and improvements have occurred. Each technology has its advantages and disadvantages and understanding these are key to determining which technology to purchase or use in certain applications.
YSI has a long history in developing and manufacturing sensors that measure dissolved oxygen in aqueous solutions and has had many firsts over the years including the invention and commercialization of the first portable dissolved oxygen instrument in 1963. This instrument utilized a membrane-covered Clark Polarographic sensor, commonly referred to as the Clark electrode, which was developed in 1956 by Dr. Leland Clark, a researcher at Antioch College who was working in collaboration with YSI scientists. Before the introduction of the Clark electrode, methods for measuring dissolved oxygen were laborious, time-consuming and highly susceptible to interference.
Today the world continues to benefit from Dr. Clark's invention as the Clark electrode is still used by many manufacturer's and in several YSI instruments. In addition to the variety of Clark electrodes offered, YSI also manufactures optical based dissolved oxygen sensors for the laboratory, spot sampling and long-term monitoring applications. YSI refers to this optical technology as ODO (optical dissolved oxygen). Other manufacturers refer to their sensors as LDO (luminescent dissolved oxygen) and RDO (rugged dissolved oxygen). Each sensor is an optical-based sensor without the membrane covered technology of Dr. Clark.
The Dissolved Oxygen Handbook is a comprehensive guide to understanding DO sensor technologies, how to maintain sensors, and how to get the best dissolved oxygen data possible.
If you've ever measured DO, or plan to at any point, you know how crucial the data is and the importance of accurate calibrations, membrane changes, and salinity compensation. Photo Credit: Luz Adriana Villa A.
Additional Blog Posts of Interest:
What is Affecting Your Dissolved Oxygen Measurements? Part 4 of 4
What is Affecting Your Dissolved Oxygen Measurements? Part 3 of 4
What is Affecting Your Dissolved Oxygen Measurements? Part 2 of 4
What is Affecting Your Dissolved Oxygen Measurements? Part 1 of 4