Dissolved oxygen sensors

Industrial bioreactors can withstand up to 3 atmospheres positive pressure. Large fermenters are equipped with a lit vertical sight glass for inspecting the contents of the reactor. Side parts for pH, temperature and dissolved oxygen sensors are a minimum requirement. A steam sterilisation sample port is provided. Mechanical agitators are installed on the top or bottom of the tank for adequate mixing. 

PW 9610 Dissolved Oxygen Sensor and PW 9600 Dissolved Oxygen Transmitter, 7600.32.9000.11, Philips, Eindhoven. 

A thin film dissolved oxygen sensor was fabricated by entrapping erythrosin B in a sol-gel matrix95. The silica sol-gel doped with the dye was deposited onto the cleaned glass slides by the spin-coating method. The sensor was linear in the most useful range of dissolved oxygen concentrations, up to 9.1 mg l 1 concentration obtained in air saturated water at 20 °C. 

McEvoy A.K., McDonagh C.M., MacCraith B.D., Development of a fiber opic dissolved oxygen sensor based on quenching of a ruthenium complex entrapped in a porous sol-gel film, SPIEProc. 2508, 190-198, (1995). 

A.K. McEvoy, C.M. McDonagh and B.D. MacCraith, Dissolved oxygen sensor based on fluorescence quenching of oxygen-sensitive ruthenium complexes immobilized in sol-gel-derived porous silica coatings, Analyst, 121(6) (1996) 785-788. 

Luz, R. D. S., Damos, F. S., Tanaka, A. A. and Kubota, L. T. (2006), Dissolved oxygen sensor based on cobalt tetrasulphonated phthalocyanine immobilized in poly-L-lysine film onto glassy carbon electrode. Sensor Actuator B Chem., 114(2) 1019-1027. 

Dissolved oxygen sensors, pH electrodes, or specific ion electrodes can be fitted, and a fluorometer for petroleum oils was developed from the chlorophyll sensor (sensitivity, 1 /xg of naphthalene/L). A solid-state bioluminescence sensor was developed (18) with a minimum detection of 5 x 10 W equivalent to about 10 quanta/s at 480 nm, sufficiently low for the detection of a single dinoflagellate flash (19). 

Sin A, Chin KC, Jamil MF, Rostov Y, Rao G, Shuler ML. The design and fabrication of three-chamber microscale cell culture analog devices with integrated dissolved oxygen sensors. Biotechnol Prog 2004 20 338-45. 

Andreescu et al. introduced a 96-electrode well-type device enabling oxygen sensing for monitoring respiratory activity of biological cells.65 65 The principal set-up of the multichannel dissolved oxygen sensor system (DOX-96) is schematically in shown in Fig. 14.13. This highly parallelized approach shows successful... 

Fig. 14-1. Schematic diagramme of (a) a membrane covered dissolved oxygen sensor and (b) diffusion ranges between cathode and outer solution.

Minimum time constants are achieved with spherical electrodes of small diameters, thin diffusion layers and high permeability of the membrane material, ie., high diffusive flux (Grasshoff, 1981). A review of data sheets of 25 commercial dissolved oxygen sensors revealed response times from 200 ms to 30 s (according to the manufacturers specification). 

It has to be noted that the calibration of dissolved oxygen sensors of the Clark type requires homogeneous temperatures from the cathode to the seawater environment. Whenever the probe-body temperature differs from the environment, the diffusive fluxes are not defined and the calibration is not valid. Most sensors require thermal equilibration times of about 20 s or more due to their considerable heat capacities, which is considerably longer than the response times. 

All bioreactors for monoseptic submerged culture have certain common features, as shown in Fig. 18. The reactor vessel is provided with side ports for pH, temperature, and dissolved oxygen sensors. Retractable sensors that can be replaced during operation are used commonly. Connections for acid and alkali (for pH control), antifoam agents. 

Zhao Y, Ye T, Chen H, Huang D, Zhou T, He C, Chen X (2011) A dissolved oxygen sensor based on composite fluorinated xerogel doped with platinum porphyrin dye. Luminescence 26(l) 29-34... 

McDonagh, C., et al. Phase fiuorometric dissolved oxygen sensor, in 5th European Conference on Optical Chemical Sensors and Biosensors. Lyon, France Sensors and Actuators, B Chemical, v 74 n 1-3 Apr 15 2001. 

Figure 6.14. Fluorescence sensor deployment platforms. (A) CTD Rosette vertical profiler. Water was pumped in series through a fluorometer and other environmental sensors, where instruments were mounted at the bottom of the Rosette and CDOM fluorometer. (Courtesy of R. Conmy.) (B) Towed vehicle with various optical and chemical sensors. (Courtesy of R.F. Chen.) (C) Minishuttle tow-yo vehicle deployed with chlorophyll and NOM fluorometers, dissolved oxygen sensor, and CTD. (Courtesy of R.F. Chen.) (D, E) Buoys, moorings, and gliders are also platforms for optical and environmental sensors. (Courtesy of Cefas.) (See Plate 10.)...

Miniaturized Dissolved Oxygen Sensors 3.4.1 Solid-State Oxygen Sensor... 

The developed dissolved oxygen sensor was capable to operate in multi-species aerobic films. The horizontal and vertical movement of the microelectrodes was controlled by a micromanipulator. Thus, the MEA could measure microprofiles of dissolved oxygen in biofilms. The results depicted that the DO concentration was high at an interface of air-saline solution due to oxygen diffusion. The DO concentration decreased within the saline-biofilm. 

Na X, Niu W, Li H, Xie J (2002) A novel dissolved oxygen sensor based on MISFET structure with Pt-LaF3 mixture film. Sensors Actuators B Chem 87(2) 222-225. doi 10.1016/S0925-... 

Martinez-Manez R, Soto J, Lizondo-Sabater J, Garcfa-Breijo E, Gil L, Ibanez J, Alcaina I, Alvarez S (2004) New potentiomentric dissolved oxygen sensors in thick film technology. Sensors Actuators B Chem 101(3) 295-301. doi 10.1016/j.snb.2004.03.008... 

McLaughlin GW, Braden K, Franc B, Kovacs GTA (2002) Microfabricated solid-state dissolved oxygen sensor. Sensors Actuators B Chem 83(1-3) 138-148. doi 10.1016/S0925-4005(02)00021-7... 

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