Electrochemical, Solid State Electrochemical and Thermocatalytic Gas sensors

Oxygen sensors usually work according to the amperometric method, in which an electrolysis flow is measured which is proportional to the oxygen concentration or the partial pressure. These sensors frequently have the disadvantage that the electrolyte material used is changed by the electrochemical reaction taking place. The sensor therefore has a limited working life, which is usually about one year.

The new electrochemical oxygen sensors from MST Intertrade (Germany) do not suffer from this disadvantage. They use a new type of electrolyte material, whose electrochemical reaction does not result in the passivation of the electrode. The working life quoted by the manufacturer is therefore at least 10 years (20.8% O2 at 20 ‘C). The sensitivity is reduced within three years by less than 15%, and after 10 years by a maximum of 30%. The sensors are available in two versions, with measuring ranges from 0% to 30% O2 or 0% to 100% O2. They can be sued in a very wide working temperature range -35’C to +50’C. The sensors show no cross-sensitivity with most gases. At a temperature of 20’C for example, 10% CO, 30% CO2 and 30% H2 do not interfere with the measurement. The company also offers micro-sensors, which are used particularly in the area of work safety for portable gas measuring devices.

These sensors are used for example in the mining industry, in order to warn miners of too low oxygen concentrations or dangerous methane concentrations. With a working life of at least three years, these sensors are also extremely durable.