Datasheet
Revised 10/12
8
TECHNICAL INFORMATION FOR TGS2620
1
10
100
0 100 200 300 400 500 600 700 800
Air
Hydrogen 1000ppm
CO 100ppm
Ethanol 300ppm
Rs (kΩ)
Elapsed time (days)
1
10
100
0 100 200 300 400 500 600 700 800
Air
Hydrogen 1000ppm
CO 100ppm
Ethanol 300ppm
Rs (kΩ)
Elapsed time (days)
0.5
Sensor unpowered
2-7 Long-term characteristics
Figure 13 shows long-term stability of TGS2620 as
measured for more than 700 days. The sensor is rst
energized in normal air. Measurement for conrming
sensor characteristics is conducted under standard
test conditions. The initial value of Rs was measured
after two days energizing in normal air at the rated
voltage. The Y-axis represents the sensor resistance
in air, 1000ppm of hydrogen, 100ppm of carbon
monoxide, and 300ppm of ethanol.
The Rs in both ethanol and hydrogen is very stable
over the test period.
Figure 14 shows the influence of storage in an
unenergized condition on the sensor’s resistance.
The sensors were stored unenergized in air after 20
days energizing, then energized for one hour before
a measurement was taken.
As the charts presented in this section illustrate, the
sensor shows stable long term characteristics.
NOTE:
The MTTF (Mean Time to Failure) can be estimated
from this data. Please refer to the Technical Advisory
MTTF Values of Figaro Gas Sensors.
Fig. 13 - Long-term stability (continuous energizing)
Fig. 14 - Inuence of unenergizing