Datasheet

Revised 08/12
6
TECHNICAL INFORMATION FOR TGS3870
0.1
1
10
0 20 40 60 80 100
Methane 1000ppm
Methane 3000ppm
Methane 9000ppm
Rs/Ro
Humidity (%RH)
20˚C
2-3 Humidity dependency
Figures 7a and 7b show the humidity dependency
of TGS3870. The Y-axis shows the ratio of sensor
resistance for gas concentrations under various
atmospheric conditions (Rs) to the sensor resistance
at 20˚C and 65%RH (Ro) for 3000ppm of methane
(Fig. 7a) and for 100ppm of CO (Fig. 7b).
0.01
0.1
1
10
0 20 40 60 80 100
CO 100ppm
CO 300ppm
CO 900ppm
Rs/Ro
Humidity (%RH)
20˚C
Figure 7a - Humidity dependency for methane sensing
(Ro = Rs in 3000ppm of CH4 at 20˚C/65%RH, VH =0.9)
Figure 7b - Humidity dependency for CO sensing
(Ro = Rs in 100ppm of CO at 20˚C/65%RH, VH =0.2)
2-4 Gas response
Figures 8a and 8b show the change patterns of sensor
resistance (Rs) when the sensor is inserted into and
later removed from 3000ppm of methane and 100ppm
of carbon monoxide respectively. Measurements were
taken every 20 seconds.
1
10
100
1000
0 120 240 360 480 600
Rs(kΩ)
Time (sec.)
airair
Gas in
CO 100ppm
VH=0.2 (CO sensing)
Figure 8b - Gas response speed - CO
Rs/RoRs/Ro
0.1
1
10
100
0 120 240 360 480 600
Rs(kΩ)
Time (sec.)
airair
Gas in
CH4 3000ppm
VH=0.9 (CH4 sensing)
Figure 8a - Gas response speed - methane
Rs(kΩ)
Rs(kΩ)