Datasheet

10. SENSOR LIFE
The data in Fig.
12 Shows fluctuations.in sensitivity with time based over
a 9 year period using some of the TGS Sensors originally produced.
Current
TGS Sensors have been considerably improved
since then but retain the
Same time dependency characteristics as the early q odels.
Fig.12 Shows
similar data on long term Operation,
but is specifically related to TGS #813
Performance.
It should be noted that since the TGS #813 is a relatively new
product, the graph covers only a three year period of testing.
In both cases these measurements were made in natura1 air rather than in
a temperature/humidity controlled environment.
The cyclic Change in sensi-
tivity corresponds to the seasonal changes in Japan with the peak sensitivity
occurring in July.
Although the data related to #813 Performance covers only a three year period,
we have found based on our extensive laboratory testings and past experience
with millions of Sensors,
that the TGS Sensors have a long-term effectiveness
for at least 8-10 years.
.
(14)