Analytical Instrumentation & Environmental Monitoring


Ross Cell technology

August 2002 Analytical Instrumentation & Environmental Monitoring

The three-electrode, polargraphic Ross Cell for monitoring dissolved oxygen (DO) consists of a platinum working electrode (cathode), a platinum counter electrode (anode) and a silver reference electrode. The reaction cell is isolated from the process solution by an oxygen permeable membrane. The oxygen that is dissolved in the process diffuses through the membrane and is reduced at the working electrode. The reverse of this reaction takes place at the counter electrode.

Since the cell generates as much oxygen as it consumes, flow dependency and frequency of maintenance are reduced. The Ross Cell sensor also has a longer lifetime than a Clark Cell sensor because its electrodes are not consumed by the electrochemical reaction as in the Clark Cell.

The Ross Cell remains at a constant potential even during changing electrode conditions. The reference electrode is connected to an internal amplifier circuit that essentially draws no current. If the voltage sensed by the reference electrode is less than the 'normal' supply voltage provided by the internal amplifier, a feedback control circuit provides a corrective voltage, changing the supply voltage to compensate for the change in cell or electrolyte resistance. This provides greater sensor accuracy and stability due to better long-term polarisation stability.

Steve Herbst, PREI Instrumentation, 011 448 2172



Credit(s)



Share this article:
Share via emailShare via LinkedInPrint this page

Further reading:

Supporting fast, safe helicopter service across Sweden
ATEQ South Africa Analytical Instrumentation & Environmental Monitoring
In an environment with high risks and fierce competition, Storm Heliworks’ fleet of eight helicopters operates on assignments throughout Scandinavia. Maintenance is critical, and the company recently invested in a battery charger analyser from ATEQ Aviation.

Read more...
WearCheck introduces advanced Legionella testing to safeguard water quality
Wearcheck Analytical Instrumentation & Environmental Monitoring
WearCheck Water has expanded its expertise in water analysis with the introduction of Legionella pneumophila detection and enumeration. This positions the company at the forefront of water and surface safety monitoring, ensuring businesses, industries, and public institutions can proactively manage legionella contamination risks.

Read more...
Silo weighing made easy - new mounting kit for load cells
Analytical Instrumentation & Environmental Monitoring
The PR 6003 mounting kit features fast commissioning in demanding applications in industrial silo weighing. It combines maximum accuracy with maximum safety in a compact system.

Read more...
Inline beverage analyser leverages advanced multi-parameter technology
Analytical Instrumentation & Environmental Monitoring
[Sponsored] The Cobrix 7501/7601 inline beverage analyser leverages advanced multi-parameter technology to enhance quality control in carbonated soft drink production.

Read more...
Smart weighing boosts Bayer’s automation
Analytical Instrumentation & Environmental Monitoring
he new supply centre of the agricultural chemical and pharmaceutical company Bayer in Hangzhou integrates weighing technology of Minebea Intec for precise mixing and homogenisation in Zone 2 hazardous areas.

Read more...
WearCheck Water wins accreditation for microbiological testing
Wearcheck Analytical Instrumentation & Environmental Monitoring
WearCheck Water’s Johannesburg laboratory was recently awarded ISO/IEC17025 accreditation for Total Coliforms and E.coli Testing after a rigorous audit process, adding to the company’s extensive list of certifications, and reinforcing the laboratory’s adherence to national and international work quality standards.

Read more...
Advancing process weighing and weighbridge automation
Analytical Instrumentation & Environmental Monitoring
Sasco Africa, a leader in industrial weighing solutions, is showcasing its latest innovations in process weighing and weighbridge automation.

Read more...
Analysis solutions for total organic carbon
Analytical Instrumentation & Environmental Monitoring
Prepare for the future of water quality monitoring with Hach’s industry-leading total organic carbon (TOC) analysis solutions.

Read more...
Liquid density analyser
Sensoquad Analytical Instrumentation & Environmental Monitoring
The SensoTech LiquiSonic system measures the density or concentration of a liquid by calculating using the sonic velocity to give output in real-time.

Read more...
Oxygen measurement in beverages
Analytical Instrumentation & Environmental Monitoring
[Sponsored] Anton Paar offers a complete range of oxygen measurement instruments for total package oxygen (TPO) measurements, at-line quality control (QC), and in-process monitoring. These instruments help beverage manufacturers achieve accurate, reliable oxygen control at every stage of production.

Read more...