Working platinum temperature sensor

Another drawback in electrochemical sensors is the long-term drift, which is sometimes related to the instability of the materials working at high temperatures. Some recent works propose the use of dispersed nanoparticles on the surface, such as platinum or gold, in order to act as a catalyst in the reduction-oxidation reaction, leading to both an increase in sensitivity and a reduction in the operating temperature (Plashnitsa et /., 2009). 

Sensors febricated in the Schottky diode configuration (using Pt as a metal catalyst) showed improved performances compared with standard thin film conductometric devices for hydrogen detection, especially in oxygen-rich environment. This has been ascribed to the catalytic effect of platinum for the chemisorption of hydrogen that also allows the sensor to work in a wide range of temperatures. 

The flame ionization detector works by measuring the current in a flame (into which the gas to be analyzed is passed) across which a potential difference of 200-400 V is applied by means of platinum electrodes. This sensor is not temperature sensitive and is capable of measuring very low concentrations. However, its primary usefulness is in detecting organic carbon atoms, and it is not suitable for hydrogen/water vapor, carbon monoxide/carbon dioxide, or oxygen/sulfur dioxide mixtures. Calibration is required for each gas mixture. 

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