Structure and Dimensions:
Basic Measuring Circuit:
REV: 04/03
The sensor requires two voltage inputs:
heater voltage (VH) and circuit voltage
(VC). The sensor has three pins: Pin #3-
-heater (+), Pin #2--sensor electrode (+),
and Pin #1--common (-). To maintain
the sensing element at specific
temperatures which are optimal for
sensing two different gases, heater
voltages of 0.9V and 0.2V are alternately
applied between pins #1 and #3 during
a 20 second heating cycle.
Circuit voltage (VC) is applied between
both ends of the sensor (Rs) and a load
resistor (RL), which are connected in
series, to allow measurement of
voltage (VRS).
Circuit voltage (Vc) should be applied
only at the moment when the signal is
taken from the sensor.
Please refer to the document
"Technical
Information for TGS3870" for details
regarding the timing and application of
Vc and VH.
Specifications:
Bottom view
Top view
Side view
The value of power dissipation (P
S) can
be calculated by utilizing the following
formula:
PS =
Sensor resistance (Rs) is calculated with
a measured value of V
RS by using the
following formula:
RS =
x RL
(VRS)
2
RS
Figaro Engineering Inc.
1-5-11 Senba-nishi
Mino, Osaka 562-8505 JAPAN
Tel.: (81) 72-728-2561
Fax: (81) 72-728-0467
email: figaro@figaro.co.jp
All sensor characteristics shown in this brochure represent typical characteristics. Actual
characteristics vary from sensor to sensor. The only characteristics warranted are those
in the Specification table above.
Sensor
RS
RH
VH
VC
(+)
(-)
VRS
(+)
(-)
1
3
2
RL
Basic measuring circuit
0.25 ± 0.05
5.0
±
0.5
0.8 ± 0.1
2.54 ± 0.2
13.0
±
0.5
Top View
Side View
Bottom
View
Pin connection:
1: Common(-)
2: Sensor electrode(+)
3: Heater(+)
9.2 ± 0.2
8.1 ± 0.2
unit:mm
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5
(VRS - 0.5VH)
(Vc-VRS)
Caution: Do not apply a constant circuit
voltage (5.0V) or the sensor would not
exhibit its specified characteristics.