TGS 203 - Carbon Monoxide Sensor Specifications - Meditronik

TECHNICAL INFORMATION FOR TGS2033-5 Initial action4Start to power on in ambient airFigure 12 shows the initial action of the sensor’svoltage output (VRL). For purposes of this test, thesensor was stored unenergized in normal air for 40days after which it was energized in clean air.After energizing, the VRL at VHH started off very highbut gradually decreased to a stable level while theVRL at VHL was so low that an alarm delay circuitwould not be required.VRL(v)VH32100.0HighLow2 min.Vc = 5.0v, Vh = 0.25 / 0.8v, RL = 3.5kΩNumber of samples tested = 5Time1.5Figure 12 - Initial actionPowered after storageof 2 weeks3-6 Influence of unenergized storageFigure 13 shows the influence of unenergized storageon sensor resistance. Sensors were storedunenergized in normal air for 2 weeks, 4 weeks, and3 months respectively after which they wereenergized. The Y-axis represents the ratio of sensorresistance in 100ppm of CO␣ after variousunenergized periods (Rs) to the resistance in 100ppmof CO after energizing at the rated voltage for 10 days(Ro).These charts demonstrate that after energizing,sensor resistance first increases slightly and thenreturns to a stable level.Rs/RoRs/Ro1.00.90.80.7+2σave.−2σ0.6-2 0 2 4 6 8 10 12Elapsed Time (days)1.51.00.90.80.7+2σave.−2σPowered after storageof 4 weeks0.6-2 0 2 4 6 8 10 12Elapsed Time (days)1.5Powered after storageof 3 monthsRs/Ro1.00.90.80.7+2σave.−2σ0.6-2 0 2 4 6 8 10 12Elapsed Time (days)Figure 13 - Time dependency (Ro = 1.0)(20 samples tested)Revised 9/99 8/14