PRODUCTINFORMATIONPRODUCT
INFORMATIONTGS1820 - for the detection of Acetone
Features:

Applications:* High sensitivity and selectivity to acetone* Low interference from ethanol and hydrogen* Quick response* Compact* Low power consumption* Acetone detectors* Breath acetone testers

TGS1820 is a hot wire semiconductor type gas sensor. The sensing element
consists of a noble metal coil embedded in a small bead of sintered metaloxide semiconductor material. Electrical conductivity change caused by gas
adsorption on the MOS material surface can be measured between both endsof the noble metal coil as a change in the combined resistance of the MOS
material and the noble metal coil.
TGS1820 has high sensitivity to acetone with small interference from ethanoland hydrogen. This feature makes the sensor ideal for breath acetone analysis.

The figure below represents typical sensitivity characteristics,
all data having been gathered at standard test conditions (seereverse side of this sheet). The Y-axis is indicated as sensor
output voltage (bridge output) difference ΔVOUT, which is defined
as follows:
ΔVOUT = Vb (Gas) – Vb (Air)Vb = Sensor output voltage (bridge output)

The figure below represents typical gas response curves. Again,
the Y-axis is indicated as sensor output voltage (bridge output)
difference ΔVOUT, which is defined as follows:
ΔVOUT = Vb (Gas) – Vb (Air)Vb = Sensor output voltage (bridge output)

Sensitivity Characteristics:

Gas Response:

180

120

160100Acetone140

Hydrogen80⊿VOUT(mV)120⊿VOUT (mV)Acetone 10ppm

Ethanol

1008060
Acetone 3ppm

4060

Acetone 1ppm

402020000.1

110Gas Concentration （ppm）1001000-20020406080100120Time (sec)

IMPORTANT NOTE: OPERATING CONDITIONS IN WHICH FIGARO SENSORS ARE USED WILL VARY WITH EACH CUSTOMER’S SPECIFIC APPLICATIONS. FIGARO STRONGLY RECOMMENDS CONSULTING OUR TECHNICAL STAFF BEFORE DEPLOYING FIGARO SENSORS IN YOUR APPLICATION AND, IN PARTICULAR, WHEN CUSTOMER’S TARGET GASESARE NOT LISTED HEREIN. FIGARO CANNOT ASSUME ANY RESPONSIBILITY FOR ANY USE OF ITS SENSORS IN A PRODUCT OR APPLICATION FOR WHICH SENSOR HAS NOTBEEN SPECIFICALLY TESTED BY FIGARO.

PRODUCT INFORMATION

Basic Measuring Circuit:
Basic measuring circuit for TGS1820
is shown in figure on the right. Circuit
voltage is applied between both endsof the sensor and a load resistor, which
are connected in series. Appropriate
circuit voltage, which also works asheater voltage, and a load resistor of
appropriate value should be determinedin order to maintain the sensing element
at a specific temperature which is optimalfor gas sensing.

The bridge output or sensor output ismeasured from a Wheatstone bridge
consisting of the sensor, a load resistor
and two opposite side resistors asshown in the basic measuring circuit.

Vb = VRL - VREF

By using a high-resolution voltmeter,sensor response can also be monitored
by measuring voltage changes acrossthe load resistor without a Wheatstonebridge circuit.

VRL

Circuit voltage (Vc)
DC2.30±0.05[V]VREF

Loadresistor (RL)
10±1%[Ω]Opposite sideresistor
510±1%[Ω]Output voltage(Vb)

Structure and Dimensions:

Sensing principle

Hot wire semiconductor type

Standard package

Plastic base and metal canTarget gases

AcetoneTypical detection range

1 ~ 20ppm

Operating temperature and humidity

0 ~ 40˚C, 10 ~ 80%RH

Electrical characteristics
under standard testconditions

Standard test conditions

Circuit voltage

2.30±0.05V DC

Load resistance10Ω ±1%Opposite side resistance510Ω ±1% (variable)

Power consumption

125mW

Sensor current≤ 85mA

Sensor output Vb (Air)-370 ~ -290mV

ΔV (1ppm Acetone) *20 ~ 60mV

Sensitivity to Acetone

1.4 ~ 2.5

ΔV(3ppm Acetone)
ΔV(1ppm Acetone)

Ethanol interference≤ 1.0ΔV(10ppm Ethanol)
ΔV(1ppm Acetone)

Hydrogen interference≤ 1.0ΔV(10ppm H2)
ΔV(1ppm Acetone)

Test gas conditions

20±5˚C/60±5%RH

Circuit conditions

Circuit voltage: 2.30±0.05V DC
Load resistance: 10Ω ±1%
Opposite side resistance: 510Ω±1%Preheating period before test
Life expectancy
at 20˚C/60%RH in normal air≥ 1 hourTop View

φ5.9±0.05

Side View

0.6 +0.02- 0.052.54±0.02

Bottom View

> 2 years*ΔV = ΔVOUT = Vb(Gas)-Vb(Air)All sensor characteristics shown in this brochurerepresent typical characteristics. Actualcharacteristics vary from sensor to sensor. The
only characteristics warranted are those in theSpecification table above.

TGS1820

12.35±0.3

TGS18204.5±0.3

Model number

Standard circuit conditions

REV: 06/23Sensor

0.25±0.05

Specifications:

Opposite sideresistor
510±1%[Ω]u/m: mm

NOTE: There is no polarity between two pins.

Before purchasing this product,
please read the Warranty Statements
shown in our webpage by scanning
this QR code.
https://www.figaro.co.jp/en/pdf/Limited_Warranty_en.pdf

FIGARO ENGINEERING INC.
1-5-11 Senba-nishi
Mino, Osaka 562-8505 JAPAN
Phone: (81)-727-28-2045
email: figaro@figaro.co.jp
www.figaro.co.jp