Winsen MC109 User manual

Catalytic Gas Sensor
（Model：MC109）
Manual
Version: 1.3
Valid from: 2014-05-01
Zhengzhou Winsen Electronics Technology Co., Ltd

Statement
This manual copyright belongs to Zhengzhou Winsen Electronics Technology Co., LTD. Without the
written permission, any part of this manual shall not be copied, translated, stored in database or
retrieval system, also can’t spread through electronic, copying, record ways.
Thanks for purchasing our product. In order to let customers use it better and reduce the faults
caused by misuse, please read the manual carefully and operate it correctly in accordance with the
instructions. If users disobey the terms or remove, disassemble, change the components inside of
the sensor, we shall not be responsible for the loss.
The specific such as color, appearance, sizes &etc, please in kind prevail.
We are devoting ourselves to products development and technical innovation, so we reserve the
right to improve the products without notice. Please confirm it is the valid version before using this
manual. At the same time, users’ comments on optimized using way are welcome.
Please keep the manual properly, in order to get help if you have questions during the usage in the
future.
Zhengzhou Winsen Electronics Technology CO., LTD

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MC109 Catalytic Flammable Gas Sensor
Profile
MC109 adopts catalytic combustion principle, and its two
arms of electric bridge consists of a test element and a
compensate element. The resistance of the test element
rises once it meets the combustible gases, in the same time,
the output voltage of the bridge changes and the voltage
variation rises in direct proportion to the gas concentration.
The compensate element, as a conference, has the function
of compensating temperature and humidity.
Features
The bridge output is linear, quick response, good repeatability
and selectivity, good stability, excellent resistance to the
interference of H2S gas and organosilicone.
Main Applications
It is widely used in industrial occasion to detect the
concentration of hydrogen, ethyne, gasoline, VOC such as
alcohol, ketone, benzene.
Technical Parameters
Model
MC109
Sensor Type
Catalytic
Standard Encapsulation
Metal, Metallurgy powder mesh
Working voltage(V)
2.5±0.1
Working current(mA)
100±10
Sensitivity
(mV)
1% H2
20～50
1% C2H4
40～90
Linearity
≤5%
Measuring range（%LEL）
0～100
Response Time (90%)
≤10s
Recovery Time (90%)
≤30s
Working Environment
-40～+70℃，less than 95%RH
Storage Environment
-20～+70℃，less than 95%RH
电桥输出
Test voltage
2.5V
- +
Fig2. Basic Test Circuit
Fig1.Sensor Structure
Bridge output

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Sensitivity, response and recovery
Changing of output signal at different temperature
Changing of output signal at different humidity
Fig5. Zero point at different temp.
Fig5. Sensitivity at different temp.
Fig3. Sensitivity Curve
Fig4. Response and recovery curve
H2
C2H2
Gasoline
C6H6
C2H5OH
Output(mV)
Output(mV)
Output(mV)
Output(mV)
Output(mV)
In CH4 gas
Time (s)
Temperature.(℃)
Temperature.(℃)
Concentration

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Changing of output signal with different voltage supplying
Long-term Stability
The drift in air per year is within ±2mV, in 1%CH4is within ±2mV. For a short period storage (in 2
weeks), the sensor need be galvanical continuously for 8 hours to reach stability. For more than one
year storage, it need more than 48 hours.
Cautions
1 .Following conditions must be prohibited
1.1 Exposed to organic silicon steam
Sensing material will lose sensitivity and never recover if the sensor absorbs organic silicon steam.
Sensors must avoid exposing to silicon bond, fixature, silicon latex, putty or plastic contain silicon
environment.
1.2 High Corrosive gas
If the sensors are exposed to high concentration corrosive gas (such as H2S, SOX, Cl2, HCl etc.), it will
not only result in corrosion of sensors structure, also it cause sincere sensitivity attenuation.
1.3 Alkali, Alkali metals salt, halogen pollution
The sensors performance will be changed badly if sensors be sprayed polluted by alkali metals salt
especially brine, or be exposed to halogen such as fluorine.
Fig10. Sensitivity fluctuation
Fig7. Zero point at different humidity
Fig8. Sensitivity at different humidity
Fig9. Zero point with different voltage
Fig9. Sensitivity with different voltage
Humidity
Humidity
In Air
In 1% CH4
Output(mV)
Output(mV)
Output(mV)
Time (weeks)

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1.4 Touch water
Sensitivity of the sensors will be reduced when spattered or dipped in water.
1.5 Freezing
Do avoid icing on sensor’s surface, otherwise sensing material will be broken and lost sensitivity.
1.6 Applied higher voltage
Applied voltage on sensor should not be higher than stipulated value, even if the sensor is not
physically damaged or broken, it causes down-line or heater damaged, and bring on sensors’
sensitivity characteristic changed badly.
1.7 Pins connection
When the sensor is connecting to the circuit, one of detection part pins and one of compensation part
pins connects as the signal output. The other one of detection part pins connects negative electrode,
while the other one of compensation part pins connects positive electrode. The part with “D”mark at the
bottom is the detection part while the other part with “C”is the compensation part.
2 .Following conditions must be avoided
2.1 Water Condensation
Indoor conditions, slight water condensation will influence sensors’ performance lightly. However, if
water condensation on sensors surface and keep a certain period, sensors’ sensitive will be decreased.
2.2 Used in high gas concentration
No matter the sensor is electrified or not, if it is placed in high gas concentration for long time, sensors
characteristic will be affected. If lighter gas sprays the sensor, it will cause extremely damage.
2.3 Long time storage
The sensors resistance will drift reversibly if it’s stored for long time without electrify, this drift is
related with storage conditions. Sensors should be stored in airproof bag without volatile silicon
compound. For the sensors with long time storage but no electrify, they need long galvanical aging
time for stability before using. The suggested aging time is 24 hours at least if the storage time is more
than half an year.
2.4 Long time exposed to adverse environment
No matter the sensors electrified or not, if exposed to adverse environment for long time, such as high
humidity, high temperature, or high pollution etc., it will influence the sensors’ performance badly.
2.5 Vibration
Continual vibration will result in sensors down-lead response then break. In transportation or
assembling line, pneumatic screwdriver/ultrasonic welding machine can lead this vibration.
2.6 Concussion
If sensors meet strong concussion, it may lead its lead wire disconnected.
2.7 Usage Conditions
2.7.1 For sensor, handmade welding is optimal way. The welding conditions as follow:
Soldering flux: Rosin soldering flux contains least chlorine
homothermal soldering iron
Temperature：250℃
Time：less than 3 seconds
2.7.2 If users choose wave-soldering, the following conditions should be obey:
Soldering flux: Rosin soldering flux contains least chlorine
Speed: 1-2 Meter/ Minute
Warm-up temperature：100±20℃
Welding temperature：250±10℃
One time pass wave crest welding machine
If disobey the above using terms, sensors sensitivity will be reduced.