Do Hamilton DO sensors?
Dissolved oxygen (DO) plays an essential role in pharmaceutical, biotech, and other high purity chemical processes. In fermentation and cell culture, the proper oxygen level supports cell growth.
What is a polarographic electrode?
In general, polarography is a technique in which the electric potential (or voltage) is varied in a regular manner between two sets of electrodes (indicator and reference) while the current is monitored. …
How does a polarographic DO sensor work?
Both galvanic DO sensors and polarographic DO sensors are types of electrochemical dissolved oxygen sensors. Once inside the sensor, the oxygen undergoes a chemical reduction reaction, which produces an electrical signal. This signal can be read by a dissolved oxygen instrument.
How does a polarographic dissolved oxygen sensor work?
Polarographic dissolved oxygen sensors are membrane based and use an electrochemical technology. Oxygen diffuses through the membrane and is reduced at a cathode that is held at a defined potential. The measured reduction current is proportional to the partial pressure of oxygen in the media.
Do fermentation DO sensors?
The high range in-line DO sensors delivered a dramatic reduction in service and maintenance requirements. The LDO spot itself is changed only once per year and calibrated twice rather than 12 times per year.
What is BOD sensor?
The BOD Sensor is the mercury-free and reliable solution for BOD determination. Easy to handle, quick and easy to read. A microprocessor-controlled pressure transducer transfers the BOD value directly to the display: results are displayed directly in mg/l with no need for further calculation.
Which electrode is used in polarography?
In polarography, mercury is used as a working electrode, because mercury is a liquid metal and thus the electrode can be renewed after each droplet.
What is BOD a measure of?
BOD is a measure of the amount of oxygen required to remove waste organic matter from water in the process of decomposition by aerobic bacteria (those bacteria that live only in an environment containing oxygen).
How is dropping mercury electrode set up?
Dropping mercury electrode (DME) is a working electrode arrangement for polarography in which mercury continuously drops from a reservoir through a capillary tube (internal diameter 0.03 – 0.05 mm) into the solution. The optimum interval between drops for most analyses is between 1 and 5 s.
What is the minimum level of oxygen allowed per OSHA?
The OSHA Respiratory Protection Standard (“the Standard”; 29 CFR 1910.134) uses 19.5 percent oxygen as the level below which an oxygen-deficient atmosphere exists and requires, generally, that all oxygen-deficient atmospheres be considered immediately dangerous to life or health (“oxygen-deficient IDLH”).
What is the electrochemistry of a PO2 electrode?
Figure 4-2 Basic electrochemistry of PO2 electrode. Oxygen is attracted to the platinum working half cell and reacts chemically with water. This reaction consumes electrons that are replaced in solution by the reaction at the silver anode.
How is blood separated from the platinum cathode?
A polypropylene membrane separates the platinum cathode from the blood. In the Clark electrode, blood is separated from the electrode terminals by use of a special membrane, which is permeable to oxygen and is a good electrical insulator.
What are the electrodes in a blood gas system?
Within all blood gas electrodes are electrode terminals (sites that chemists would refer toas electrodes). An electrode terminal is a solid site where electrons enter or leave a liquid medium. Electrode terminals may consist of metal or glass. A single electrode terminal in contact with an electrolyte solution may also be called a half-cell.
How is blood separated from the electrode terminals?
In the Clark electrode, blood is separated from the electrode terminals by use of a special membrane, which is permeable to oxygen and is a good electrical insulator. Oxygen from the blood can diffuse easily through the membrane into the electrolyte solution in which the reaction with water can take place.