TECHNICAL INFORMATION FOR TGS8100
an ISO9001 company
Technical Information for Air Quality Control Sensors
The Figaro 8100 is a new MEMStype semiconductor air quality
sensor. Combining advanced
Micro Electro Mechanical Systems
technology (MEMS) with Figaros
extensive experience in metal
oxide type gas sensing sensors,
Figaro has developed a new indoor
air quality sensor with extremely
low power consumption and
small size. With its excellent durability and stability, TGS8100 is ideal
for applications such as air cleaners, air conditioners and ventilation
fan activation in home and office settings.
Page
Specifications
Features..........................................................................2
Applications...................................................................2
Structure..........................................................................2
Basic measuring circuit....................................................2
Circuit & operating conditions.........................................3
Specifications..............................................................................3
Dimensions...............................................................................3
Driving conditions...........................................................................4
Basic Sensitivity Characteristics
Sensitivity to various gases................................................4
Temperature and humidity dependency..........................5
Gas response.........................................................................5
Initial action........................................................................6
Long term characteristics............................................................6
Effects of air flow............................................................................7
Durability to HMDS...............................................................7
Soldering conditions..........................................................8
Packaging method...........................................................8
Cautions........................................................................................9
IMPORTANT NOTE: OPERATING CONDITIONS IN WHICH FIGARO SENSORS ARE USED WILL VARY
WITH EACH CUSTOMERS SPECIFIC APPLICATIONS. FIGARO STRONGLY RECOMMENDS CONSULTING
OUR TECHNICAL STAFF BEFORE DEPLOYING FIGARO SENSORS IN YOUR APPLICATION AND, IN
PARTICULAR, WHEN CUSTOMERS TARGET GASES ARE NOT LISTED HEREIN. FIGARO CANNOT
ASSUME ANY RESPONSIBILITY FOR ANY USE OF ITS SENSORS IN A PRODUCT OR APPLICATION FOR
WHICH SENSOR HAS NOT BEEN SPECIFICALLY TESTED BY FIGARO.
Revised 04/15
TECHNICAL INFORMATION FOR TGS8100
1. Specifications
MEMS chip
Sensor element
1-1 Features
* Surface mount package
* Low power consumption
* High sensitivity to cigarette smoke, cooking
odors, and gaseous air contaminants
* Long life
* Low cost
Sensor cap
1-2 Applications
* Indoor air quality monitors
* Air cleaners
* Ventialtion control
* Kitchen range hood control
XXXXXX
Sensor base
1-3 Structure
Figure 1 shows the structure of TGS8100. The MEMS
chip contains a sensor element with heater. The
sensors (+) electrode is connected to pin No.3 and
the (-) electrode is connected to pin No.2. The sensing
material is heated by a heater connected to pins No.1
and No.4. Lead wires are Au and connected to sensor
pad which is also made of Au. The sensor base is
made of alumina. The sensor cap is made of 42 alloy
and contains 2 pin holes on the sensors top.
Fig. 1 - Sensor structure
(+)
3
4
VH
VC
Revised 04/15
GAS
RL
1-4 Basic measuring circuit
Figure 2 shows the basic measuring circuit. The
sensor requires two voltage inputs: heater voltage
(VH) and circuit voltage (VC). The heater voltage (VH)
is applied to the integrated heater in order to maintain
the sensing element at a specific temperature which
is optimal for sensing. Circuit voltage (VC) is applied
to allow measurement of voltage (VOUT) across a load
resistor (RL) which is connected in series with the
sensor. DC voltage is required for the circuit voltage
since the sensor has a polarity. The value of the load
resistor (RL) should be chosen to optimize the alarm
threshold value.
RS
RH
Pulse
VOUT(VRL)
( )
Fig. 2 - Basic measuring circuit
Sensor resistance (Rs) is calculated with a measured
value of VOUT(VRL) by using the following formula:
V
RS = ( C - 1) x RL
VRL
Formula to determine Rs
TECHNICAL INFORMATION FOR TGS8100
1-5 Circuit & operating conditions
1-7 Dimensions
The ratings shown below should be maintained at all
times to insure stable sensor performance:
Specification
Circuit voltage (VC)
max 3.0V DC for 2msec
0V for 998msec
Heater voltage (VH)
1.8V DC2% (NOTE 3)
3.20.2
4
TGS8100
2.50.2
Item
Top view
1139B2
1
Load resistance (RL)
Side view
110 (typical)
0.990.15
Heater resistance (room temp)
variable (10k min.)
Operating & storage temperature
-10C ~ +50C
Optimal detection concentration
1 ~ 30ppm H2
Bottom View
1.2
0.10
1.0
1-6 Specifications NOTE 1
Item
Sensor resistance (air)
Specification
2
10k ~ 300k
Sensor resistance gradient ()
~ 0.6
u/m = mm
Pin connections:
1: Heater
2: Sensor electrode (-)
3: Sensor electrode (+)
4: Heater
= Rs(10ppm hydrogen)/Rs(air)
15mW (typical)
NOTE 1: Sensitivity characteristics are obtained
under the following standard test conditions:
(Standard test conditions)
Temperature and humidity: 20 2C, 65 5% RH
Preheating period: 1 hour or more under standard circuit
conditions.
NOTE 2: TGS8100 is an ESD-sensitive device. Figaro
recommends using ESD protection equipment for
handling the sensor.
NOTE 3: Please regulate heater voltage as specified
in the above table. Sensor performance may differ
from that shown in this brochure if specified heater
voltage is not maintained.
All sensor characteristics shown in this brochure
represent typical characteristics. Actual
characteristics vary from sensor to sensor and
from production lot to production lot. The only
characteristics warranted are those shown in
the Specification table above.
Revised 04/15
Fig. 3 - Sensor dimensions
1.85
Heater power consumption (PH)
1.05
8.4mA (typical)
1.05
Heater current (RH)
1
Index
1.3
1.3
3.6
Fig. 4 - Recommended land pattern
Mechanical Strength:
The sensor shall have no abnormal findings in
its structure and shall satisfy the above electrical
specifications after the following performance tests:
Vibration - f re q u e n c y - 1 0 ~ 5 5 H z , t o t a l
amplitude-1.5mm, duration-two
hours, direction-X Y Z
Drop - 50 times from 1m height onto a
tile floor
3
TECHNICAL INFORMATION FOR TGS8100
Driving conditions of TGS8100
VH: 1.8V (Continuous energizing)
1sec
0.002sec
Vc: 3.0V
Vc: 0V
Fig. 5 - Driving conditions of TGS8100
2. Basic Sensitivity Characteristics
10
2-1 Sensitivity to various gases
Figure 6 shows the relative sensitivity of TGS8100
to various gases. The Y-axis shows the ratio of the
sensor resistance in various gases (Rs) to the sensor
resistance in clean air (Ro) taken at standard test
conditions of 20C/65%RH.
Air
Methane
Iso-butane
Rs/Ro
CO
Hydrogen
0.1
Figure 7 shows the relative sensitivity of TGS8100 to
various gases in cigarette smoke. The Y-axis shows
the ratio of the sensor resistance in cigarette smoke
(Rs) to the sensor resistance in clean air (Ro) taken at
standard test conditions of 20C/65%RH. This data
was taken in a 20m3 room with cigarettes placed on
a flat surface. The burning time for one cigarette
was approximately 8 minutes. (Note: Generally, the
activation point for an air cleaner would be around Rs/
Ro=0.85, while the Rs/Ro for just one cigarette is as low as
0.65, making this sensor ideal for air cleaner application).
This data shows that TGS8100 has good sensitivity
to low concentrations of air contaminants, including
those found in cigarette smoke.
NOTE:
All sensor characteristics in this technical brochure
represent typical sensor characteristics.
Ethanol
0.01
10
100
1000
Gas concentration (ppm)
Fig. 6 - Sensitivity to various gases (Rs/Ro)
1.0
0.5
Rs/Ro
0.1
0
2
3
Number of cigarettes
Fig. 7 - Sensitivity to cigarette smoke (Rs/Ro)
Revised 04/15
TECHNICAL INFORMATION FOR TGS8100
2-2 Temperature and humidity dependency
10
Figure 8 shows the temperature and humidity
dependency of TGS8100 in clean air. The Y-axis
shows the ratio of sensor resistance in clean air under
various atmospheric conditions (Rs) to the sensor
resistance in clean air at 20C/65%RH (Ro).
RH
(C)
40%RH
65%RH
85%RH
100%RH
-10
1.46
1.21
10
1.28
1.15
1.08
20
1.11
1.00
0.94
30
0.98
0.87
0.82
40
0.87
0.78
0.73
50
0.78
0.69
0.65
100% R.H.
1
Rs/Ro
40% R.H.
65% R.H.
85% R.H.
0.1
-10
10
20
30
40
Ambient temperature (C)
50
60
Fig. 8 - Temperature and humidity dependency (Rs/Ro)
in clean air
Table 1 - Temperature and humidity dependency
(typical values of Rs/Ro for Fig. 8)
Table 1 shows a table of values of the sensor s
resistance ratio (Rs/Ro) under the same conditions
as those used to generate Figure 8.
2-3 Gas response
Figure 9 shows the response pattern of the sensor
when inserted into and later removed from 10ppm
of hydrogen after a 3 minute period. The Y-axis
shows the ratio of sensor resistance over time (Rs)
compared with sensor resistance in clean air just prior
to insertion into hydrogen (Ro).
As this chart indicates, the sensors response speed
to the presence of gas is extremely quick, and when
removed from gas, the sensor will recover back to its
original value in a short period of time.
Revised 04/15
10
1
Rs/Ro
0.1
6
Time (min.)
10
Fig. 9 - Gas response to hydrogen
TECHNICAL INFORMATION FOR TGS8100
2-4 Initial action
Figure 10 shows the initial action of the sensor
resistance (Rs) for a sensor which is stored unenergized in normal air for 7 days and then energized in clean
air. The Y-axis represents sensor resistance in clean
air at various times after energizing (Rs) compared
with sensor resistance 20 min. after energizing (Ro).
The Rs drops sharply for the first seconds after
energizing, regardless of the presence of gases, and
then reaches a stable level according to the ambient
atmosphere. Such behavior during the warm-up
process is called Initial Action.
Since this initial action may cause an air cleaner to
activate unnecessarily during the initial moments
after powering on, it is recommended that an initial
delay circuit be incorporated into the devices design .
10
1
Rs/R0
0.1
10
15
20
Time (min)
Fig. 10 - Initial action
1000
100
Rs (k)
10
2-5 Long-term characteristics
Figures 11-12 show the long-term stability of TGS8100
as measured for more than 250 days. In Figures
11 & 12, the sensor is first energized in normal air.
Measurement for confirming sensor character-istics
is conducted under standard test conditions. Figure
11 depicts sensor resistance in clean air over the test
period, while in Figure 12 the Y-axis shows the ratio of
sensor resistance in gases (Rs) compared with sensor
resistance in fresh air on the same day (Ro).
1
0
50
100
150
200
250
300
Elapsed time (days)
Fig. 11 - Long-term stability (continuous energizing)
in clean air
10
Rs/R0
0.1
0
0
50
100
150
200
250
300
Elapsed time (days)
Fig. 12 - Long term stability (continuous energizing)
in 10ppm H2
Revised 04/15
TECHNICAL INFORMATION FOR TGS8100
2-6 Effects of air flow
Vertical
Fig. 14 charts how the sensor is affected by an air flow
that is generated as illustrated in Fig. 13. This data
demonstrates that there is no significant influence on
the sensor by an air flow of 7.6m/sec.
Air flow direction
Horizontal
TGS8100 side view
Fig. 13 - Air flow test direction
10
Horizontal wind
7.6m/sec
Vertical wind
7.6m/sec
Rs/R0
0.1
30
60
90
120
150
180
210
Time (min)
Fig. 14 - Effect of air flow
1000
In Fig.15a, the Y-axis shows the sensor resistance in
10ppm hydrogen and air. In Fig.15b, the Y-axis shows
the ratio of sensor resistance in 10ppm hydrogen
(Rs) compared with sensor resistance in fresh air on
the same day (R0). As Fig.15a shows, both sensor
resistance (Rs) in air and in 10 ppm of hydrogen
decreased for the first 10 minutes of exposure to
10ppm HMDS. However, as Fig.15b shows, there is
no significant change in Rs/R0.
100
Air
10ppm H2
10
Before exposure
After 10ppm/1 hr
After 10ppm/5 hrs
Fig. 15a - Effect of HMDS exposure (Rs)
10
Rs/R0
Figure 15 shows the effects on TGS8100 of silicone
vapor exposure. Sensor resistance prior to HMDS
(hexamethyldisiloxane) gas exposure was measured.
Energized sensors were placed into an environment
of 20C/50%RH. In this environment, the sensors
were exposed to 10 ppm of HMDS. When measuring
sensor resistance, sensors were returned to normal
air for 1 hour. After the measurement for 1 hour, the
sensors were returned to HMDS exposure.
Rs(k)
2-7 Durability to HMDS
Air
1
10ppm H2
0.1
Before exposure
After 10ppm/1 hr
After 10ppm/5 hrs
Fig. 15b - Effect of HMDS exposure (Rs/R0)
Revised 04/15
TECHNICAL INFORMATION FOR TGS8100
2-8 Soldering conditions
Preheat
Temperature
Period
Figaro has confirmed that reflow soldering can
be done under the conditions shown in Table 2. If
different soldering conditions are desired, users
should conduct a test before production starts to see
if there would be any adverse influence to sensor
characteristics.
Main heat 1
130~160C
150~180C
41 sec
60~120 sec
Temperature
170C
Period
Main heat 2
123.5 sec
Temperature
Period
225C
235~245C
16.5 sec
30~60 sec
Peak temperature of main heat
231.5C
Ambient gas
Nitrogen
Table 2 - Reflow soldering conditions
2-9 Packing Method
Direction of feed
Fig. 16 shows the structure of standard packaging for
TGS8100. Figs. 17 and 18 show the dimensions of the
packaging tape and reels.
Cover tape
Round sprocket holes
XX
XX
TG
S8
10
XX
XX
TG
S8
10
XX
XX
TG
S8
10
4.00.1
Package tape
1.750.1
Round sprocket holes
2.000.05
1.5+0.1
Fig. 16 - TGS8100
packaging structure
0.250.05
3.50+0.1/-0.05
3.65
0.1
1.30+0.1/-0.05
3.65
8.0+0.3/-0.1
2.95
0.1
0.250.05
3.50+0.1/-0.05
(0.03)
XXXXXX
TGS8100
XXXXXX
TGS8100
XXXXXX
TGS8100
TGS8100
XXXXXX
1.30+0.1/-0.05
2.80+0.1/-0.05
2.95
0.1
XXXXXX
TGS8100
(0.03)
XXXXXX
TGS8100
XXXXXX
TGS8100
XXXXXX
TGS8100
TGS8100
XXXXXX
XXXXXX
XXXXXX
TGS8100
TGS8100
4.00.1
TGS8100
XXXXXX
TGS8100
TGS8100
4.00.1
8.0+0.3/-0.1
1.5+0.1
3.500.05
Round sprocket holes
2.000.05
1.750.1
3.500.05
4.00.1
0.1
Fig.14 - Dimensions of package tape
2.80+0.1/-0.05
0.2
60+1.0/-0
180+0/-1.5
180+0/-1.5
3
1
12
60+1.0/-0
12
12
12
Fig. 17Fig.14
- Dimensions
of packaging
tape
- Dimensions of package
tape
9.0+1.0/-0
11.41.0
.2
3 0
9.0+1.0/-0
11.41.0
Dimensions of package reel
Fig. Fig.15
18 - -Dimensions
of tape reel
Revised 04/15
Fig.15 - Dimensions of package reel
TECHNICAL INFORMATION FOR TGS8100
3 Cautions on Usage of Figaro Gas Sensors
3-1 Situations which must be avoided
1) Exposure to silicone vapors
If silicone vapors adsorb onto the sensors surface, the
sensing material will be coated, irreversibly inhibiting
sensitivity. Avoid exposure where silicone adhesives,
hair grooming materials, or silicone rubber/putty
may be present.
2) Highly corrosive environment
High density exposure to corrosive materials such
as H2S, SOx, Cl2, HCl, etc. for extended periods may
cause corrosion or breakage of the lead wires or
heater material.
3) Contamination by alkaline metals
Sensor drift may occur when the sensor is contaminated by alkaline metals, especially salt water spray.
4) Contact with water
Sensor drift may occur due to soaking or splashing
the sensor with water.
5) Freezing
If water freezes on the sensing surface, the sensing
material would crack, altering characteristics.
6) Application of excessive voltage
If higher than specified voltage is applied to the
sensor or the heater, lead wires and/or the heater may
be damaged or sensor characteristics may drift, even
if no physical damage or breakage occurs.
7) Operation in zero/low oxygen environment
TGS sensors require the presence of around 21%
(ambient) oxygen in their operating environment in
order to function properly and to exhibit characteristics
described in Figaros product literature. TGS sensors
cannot properly operate in a zero or low oxygen
content atmosphere.
8) Polarization
These sensors have polarity. Incorrect Vc connection
may cause significant deterioration of long term stability.
Please connect Vc according to specifications.
Revised 04/15
3-2 Situations to be avoided whenever possible
1) Water condensation
Light condensation under conditions of indoor usage
should not pose a problem for sensor performance.
However, if water condenses on the sensor s
surface and remains for an extended period, sensor
characteristics may drift.
2) Usage in high density of gas
Sensor performance may be affected if exposed
to a high density of gas for a long period of time,
regardless of the powering condition.
3) Storage for extended periods
When stored without powering for a long period,
the sensor may show a reversible drift in resistance
according to the environment in which it was
stored. The sensor should be stored in a sealed bag
containing clean air; do not use silica gel. Note that
as unpowered storage becomes longer, a longer preheating
period is required to stabilize the sensor before usage.
4) Long term exposure in adverse environment
Regardless of powering condition, if the sensor
is exposed in extreme conditions such as very
high humidity, extreme temperatures, or high
contamination levels for a long period of time, sensor
performance will be adversely affected.
5) Vibration
Excessive vibration may cause the sensor or lead
wires to resonate and break. Usage of compressed
air drivers/ultrasonic welders on assembly lines may
generate such vibration, so please check this matter.
6) Shock
Breakage of lead wires may occur if the sensor is
subjected to a strong shock.
7) Influence by static electricity
TGS8100 is an ESD-sensitive device. Figaro
recommends using ESD protection equipment for
handling the sensor.
TECHNICAL INFORMATION FOR TGS8100
Figaro USA Inc. and the manufacturer, Figaro
Engineering Inc. (together referred to as Figaro)
reserve the right to make changes without notice to
any products herein to improve reliability, functioning
or design. Information contained in this document is
believed to be reliable. However, Figaro does not
assume any liability arising out of the application or
use of any product or circuit described herein; neither
does it convey any license under its patent rights, nor
the rights of others.
Figaros products are not authorized for use as critical
components in life support applications wherein a
failure or malfunction of the products may result in
injury or threat to life.
FIGARO GROUP
Revised 04/15
HEAD OFFICE
OVERSEAS
Figaro Engineering Inc.
1-5-11 Senba-nishi
Mino, Osaka 562 JAPAN
Tel.: (81) 72-728-2561
Fax: (81) 72-728-0467
email: figaro@figaro.co.jp
Figaro USA Inc.
121 S. Wilke Rd. Suite 300
Arlington Heights, IL 60005 USA
Tel.: (1) 847-832-1701
Fax.: (1) 847-832-1705
email: figarousa@figarosensor.com
10
