CALIBRATION TECHNIQUES OF GAS SENSORS AND SENSORSPECIFIC SIGNAL PROCESSING

Abstract

The calibration techniques of gas sensors are powerful and irreplacible tools for measuring multidimensional characteristique fields and are guarantying more reliability in practical application. It is wellknown, that gas sensors normally are as well influenced by parameters as temperature, pressure, massflow and moisture as there often exist non linear cross-sensitivities to other related gases. All these properties effect that in the past the suitability of gas sensors for analytical measurement was not sufficient enough. In spite of all these disadvantages there is a real chance for utilization in analytical instrumentation, when only the sensors are working reproducible under equal conditions. By means of high-performance microprocessortechnology combined with high standard gascalibration techniques it is possible to create low cost and wellworking smart sensor systens. The act of part is, to prepare very carefully the multicomponent testgases, which have to be controlled by corresponding analytical methods. Considering that the sensors are even formed to all the relevant parameters, as temperature, pressure, massflow and moisture, the microprocessor controlled signal recording can be done. Last but not least it is unimportet which gas sensor signals has to be recorded. For all detectable signals like current, voltage, capacity or any impedance relationship there exist high sensitive and corresponding measuring-programs. Therefore it is possible to measure not only "chemical sensors" like chem-FETs or semiconductor divices but also sensors which are based on biological or enzymatical materials.