سنسور میدان اثر سیستمهای اطلاعات برای تمرکز پایین H2S برای پایش محیطی

It was found, that Metal Insulator Semiconductor Field Effect (MIS-FE) sensors with structures Pd–Si3N4–SiO2–Si and Pd–Ta2O5–SiO2–Si have sufficient concentration resolution to H2S gas and acceptable response time in mixture of H2S gas with air. Results of MIS-FE gas sensor operation in periodic regime are presented and allow us to be sure, that low detection level of H2S for MIS-FE sensor with Ta2O5–SiO2 insulator is of about 5 ppb.

H2S gas measurement in air is a very specific problem because hazardous concentration for human health is very low (for residence area is around 5 ppb and 14 ppm for working zone according to Russian standard of environmental protection); ppb-level delectability is not achieved for usual liquid electrochemical sensors, and also there are several important applications, where these sensors non-applicable because of short life time and extremely working condition such as humidity extremes (very dry or too much humid atmosphere), temperature drop or operation under permanently high concentration of H2S. Therefore, the purpose of this work was the creation of inexpensive and simple device for low H2S concentration measurement based on chip solid state gas sensor.

In this work, we continue our investigations [1, 2, 4 - 8] in field of physics MIS-FE gas sensors and as result design device suitable for selective detection of low concentration of H2S gas in air. Results of MIS-FE gas sensor operation in periodic regime allow us to be sure, that low detection level of H2S for MIS-FE sensor with Ta2O5-SiO2 insulator is of about 5 ppb. Confirming by experiment storage life without losses of quality of sensors is more when one year. Experimental data is evidence that achieve characteristic of sensor’s properties typical for completely commercial product.