TGS821 Datasheet, PDF (2/2 Pages) List of Unclassifed Manufacturers – SPECIAL SENSOR FOR HYDROGEN GAS

Structure and Dimensions:
19.5 ± 0.5
um : mm
1.0 ± 0.05
6
5
1
2
4
3
9.5 ± 0.3
13.5
+ 0.3
- 0.2
1 Sensing Element:
SnO2 is sintered to form a thick film on
the surface of an alumina ceramic tube
which contains an internal heater.
2 Sensor Base:
Alumina ceramic
3 Flame Arrestor:
100 mesh SUS 316 double gauze
Pin Connection and Basic Measuring Circuit:
The numbers shown around the sensor symbol in the circuit diagram at the
right correspond with the pin numbers shown in the sensor's structure drawing
(above). When the sensor is connected as shown in the basic circuit, output
across the Load Resistor (VRL) increases as the sensor's resistance (Rs) de-
creases, depending on gas concentration.
Standard Circuit Conditions:
Basic Measuring Circuit:
Item
Heater Voltage
Circuit Voltage
Symbol
VVHH
VVCC
Rated Values
5.0±0.2V
Max. 24V
Load Resistance
RRLL
Variable
Remarks
AC or DC
AC or DC
*PS 15mW
*PS 15mW
Electrical Characteristics:
Item
Sensor Resistance
Change Ratio of
Sensor Resistance
Heater Resistance
Heater Power
Consumption
Symbol
Rs
α
RH
PH
Condition
Hydrogen at 100ppm/Air
Log[Rs(H2 100ppm)/Rs(H2 1000ppm)]
Log (1000ppm / 100ppm)
Room temperature
VH=5.0V
Specification
1k ~ 10k
0.6~1.20
38.0 ± 3.0
660 ± 55 mW
Standard Test Conditions:
TGS 821 complies with the above electrical characteristics
when the sensor is tested in standard conditions as speci-
fied below:
Test Gas Conditions: 20°±2°C, 65±5%R.H.
Circuit Conditions: VC = 10.0±0.1V (AC or DC),
VH = 5.0±0.05V (AC or DC),
RL = 4.0kΩ±1%
Preheating period before testing: More than 7 days
FIGARO USA, INC.
3703 West Lake Ave. Suite 203
Glenview, Illinois 60025
Phone: [phone]
Fax:
(847)-832-1705
email: [e-mail]
Sensor Resistance (Rs) is calculated by
the following formula:
Rs = (
VC
VRL
-1) x RL
Power dissipation across sensor electrodes
(Ps) is calculated by the following formula:
2
VC x Rs
Ps =
2
(Rs + RL)
For information on warranty, please refer to Standard Terms and
Conditions of Sale of Figaro USA Inc.
REV: 9/99