City Technology White Paper examines the market forces behind the development of its new lead-free long-life oxygen sensor


A white paper published this week in Sensors Journal by Dr. Martin Willett, a sensing technology expert at City Technology, demonstrates the market and regulatory factors driving demand for long-life oxygen sensors.

At the forefront of innovation in this field, Honeywell Company City Technology has developed a long life, lead-free oxygen sensor designed to meet the evolving customer needs in industrial safety applications. The White Paper entitled 'Oxygen Sensing for Industrial Safety - Evolution and New Approaches', points to a combination of legislative, commercial and performance considerations driving City Technology's recent innovations in oxygen sensing.

Willett said: "City's oxygen sensors are typically used in a wide range of industrial environments including oil & gas, refining, petrochem, mining & tunnelling to provide early warning of oxygen deficiency and potentially life threatening conditions. Oxygen sensors have traditionally used consumable lead anodes, which limits the sensor's life to typically two years. The use of lead is also undesirable given increasing restrictions due to health and environmental impacts. The requirement to deliver sensors with longer life and reduced toxic materials was a key factor behind City Technology's R&D process to evolve alternative, oxygen sensor technologies."

City Technology understands that in addition to prolonging the guaranteed life of oxygen sensors, a key concern for customers globally is the requirement for sensors to operate in extreme conditions typical of many industrial processes without impacting reliability and performance.

Willett added, "To satisfy customer demands in challenging industrial applications, City Technology has sought to further the development of electrochemical oxygen pump technology that we first introduced for flue gas emission applications three years ago.

One key focus has been improvements in water management and ensuring electrolyte is retained within correct areas of the sensor at all times. This results in sensors with excellent performance across a wide range of environmental conditions from very cold and dry to hot and wet.

Willett concluded: "The gas detection industry's need for reliable, long life sensors means many sensor technologists now expect oxygen pump technology to be the preferred solution for industrial safety applications in the coming years. City Technology is at the cutting edge of sensor development and it is through continuous innovation and investment in R&D that the company has maintained its market leading position".



Dr Martin Willett joined City Technology in 1994 and is currently Intellectual Property and External Research Manager. He joined the National Coal Board's Mining Research & Development Establishment in 1978 and developed a variety of electrochemical, semiconductor, catalytic and optical environmental monitoring sensors for use in underground mines. He has a BSc in Physics from Birmingham University and a PhD in Chemistry from Nottingham University.

The white paper has been published by Sensors (ISSN 1424-8220; CODEN: SENSC9), the leading international, peer-reviewed, open access journal on the science and technology of sensors and biosensors. See link to white paper at

Sensors is published monthly online by the Multidisciplinary Digital Publishing Institute (MDPI).


City Technology leads the global market in the manufacture and sale of innovative and reliable gas sensors for use in personal and fixed life safety systems. Every day, 50 million people around the world trust City Technology sensors to keep them safe and protect them from harmful gases.

Each of our 400 staff at our facilities in the UK, Germany, China, Taiwan and the USA shares the same single-minded commitment to applying innovative technology to improve life safety. With the customer at the heart of everything, we apply our sensing technology to wherever safety is paramount: from harsh, hazardous environments to transit situations, at home, at work and even in hospitals.

With a range of more than 300 products detecting 28 different gases, City Technology is the number one choice for sensing technology. The company is owned by Honeywell, a Fortune 100 diversified technology and manufacturing leader.

For more information, visit City Technology's new website at


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Francis Mote
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