Table 1.

Cross-sensitivity of the sensor based on spark-discharge-synthesized tin dioxide to some physiologically important gases at temperatures taken for the measurements of hydrogen response of the sensor (450 °C).

	Pure Air RH 30% (R30)	Pure Air RH 85%	Air + Lactate RH 85% *	Air + NH3 RH 85% **
R, kΩ	1090	990	760	1010
Response *** (Rg − R30)/R30, %	-	8 ± 1	30 ± 5	7 ± 1

* Lactate concentration obtained by bubbling air through 1 mol/L solution of lactate in distillated water. ** Ammonia concentration obtained by bubbling air through 0.1 mol/L solution of NH₃ in distillated water. *** Sensor response to different gases is measured as (Rg − R₃₀)/R₃₀, where R₃₀ is sensing layer resistance at 30% relative humidity, and Rg is the resistance in the appropriate gas mixture.