1. 1 RESISTIVE GAS SENSORS WITH POLYMER FILMS Bashirova S.M. National Aerospace Agency, Baku, Azerbaijan

2. 2 Resistive element based on metaloksid semiconductor. The structure of metaloksidThe selectivity curves semiconductor Positives: Low cost, high sensitivity Negatives: Low selectivity, high working temperatures (from 300 to 500°C )

3. 3 Electrochemical element Construction of the sensor based on a solid electrolyte 1- the heater (platinum) 2 – contacts, 3 - sealing (glass) 4 - the measuring electrode (anode), 5 solid electrolyte, 6 - electrode (cathode) Positives: Low cost, high sensitivity Negatives: low selectivity, very high working temperatures, the life of electrochemical elements is small (one - three years).

4. 4 Resistive gas sensing structure 1-sapphire crystal (size 3x3 mm) 2 - copper wire (diameter 200 micrometers), 3 - contact pads (400x400 mm), 4-counter electrode included, 5 - resistive heater.

5. 5 The structural formula of phthalocyanines R М = SiCl 2 М = Cu, R–SO 2 –NH–C 18 H 37 For CuPc

6. 6 The dynamic of adsorption-desorption processes for samples with copper Pc layer exposed in NO x (3 ppm) a) - before heat treatment, b) - after heat treatment at 180°C. I - current value while samples exposed in NOx, Io - before exposure in NOx.

7. 7 Dependence of resistance value versus concentration of NOx ( SiPcCl 2 films) Dependence of resistance value on time for different concentrations of NO x

8. 8 The ransformer bridge The resonant amplifier The detector The indicator The generator of a sinusoidal signals Блок питания The device for determining the concentrations of nitrogen oxides Technical data Nominai range -0-500 ppm, Bias Voltage -9 V Response time – less than 10 sec. Operating Temperature Rating - -20°C Ta +55°C Expected Operation Life- 5 year Dimensions - 200x70x45 Weight – less than 0.7 kg., The Block scheme of a gasanalyzer device

9. 9 Reasons for using the structures with polymer films 1.Improved Selectivity 2.High sensitivity 3.Reduced Drift 4.Possibility of manufacturing by a microelectronic technology 5.Cheap and available polymeric materials 6.Low Cost