Figaro TGS2611-C00 TGS 2611 Gas Sensor For LP Gases Methane (Ø x H) 9.2 mm x 7.8 mm TGS2611-C00 Hoja De Datos

12

TECHNICAL INFORMATION FOR TGS2611

To simulate the conditions of an improperly
conducted lighter gas test, an energized sensor was
exposed to 10% iso-butane for 60 seconds under
standard circuit conditions. After returning the sensor
to normal air, the Rs in air, 3000, 5000, and 9000 ppm
of methane was measured at the intervals after
exposure as shown in Figure 20.

The result of the above test is shown in Fig. 20. A
10% iso-butane exposure for 60 seconds appears to
cause an increase in Rs in gas. Furthermore, sensor
resistance would take more than one week to recover
to its original value after energizing in normal air.

Prolonged exposure to in excess of 10% iso-butane
may cause a permanent change in the sensor ’s
characteristics due to combustion of gas on the
surface of the sensing material and/or heater.
Therefore, Figaro cautions that, if a lighter gas test is
done, it must be carefully administered to avoid
sensor damage.

: To achieve the optimal level of accuracy in

gas detectors, each TGS2611 sensor should be
individually calibrated by matching it with a load
resistor (R

L

) in an environment containing the target

gas concentration for alarming (refer to Fig. 2).

For the convenience of users, TGS2611 is classified
into 24 groups according to the each sensor’s Rs in
methane. ID numbers marked on the sensor’s body
indicate the sensor’s grouping. Individual sensor
calibration can be eliminated by matching the sensor
with the recommended R

L

 for each  sensor ID.

However, because group calibration is used instead
of individual calibration, an average of 10% less
accuracy would result for detectors using group
calibration. Please refer to “Application Notes for
TGS2611” for more information.

4-1  Situations which must be avoided
1) Exposure to silicone vapors
If silicone vapors adsorb onto the sensor’s 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

0.1

1

10

Before

exposure

4 min. after

exposure

1 day after

exposure

1 week after

exposure

Rs (air), k

Ω

Rs (5000ppm methane), k

Ω

ß: Rs(9000ppm methane)/Rs(3000ppm methane)

Fig. 20 - Lighter gas exposure test of TGS2611-C00

as H

2

S, SOx, Cl

2

, 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 Figaro’s product
literature. TGS sensors cannot properly operate in a
zero or low oxygen content atmosphere.

8) Excessive exposure to alcohol
IF TGS2611-E00 is exposed to high concentrations of
alcohol (such as 10,000ppm or more) for a long period
of time, the filter may become saturated. In this case,