Winsen MC227D Catalytic Flammable Gas Sensor User Manual

: June 14, 2024
: Winsen

Table of Contents

Statement
MC227D Catalytic Flammable Gas Sensor
Sensitivity and Response Feature
Cautions
References
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Catalytic Flammable Gas Sensor
(Model: MC227D)
User’s Manual
Version: 1.2
Valid from: 2022-7-29

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.

MC227D Catalytic Flammable Gas Sensor

Product
MC227D 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
Bridge output voltage in linear
Fast response
Good repeatability and selectivity
Good stability and reliability
Resist H2S poisoning & organosilicone.

Main Applications
It is widely used in public places (not industrial occasion) to detect the concentration or leakage of combustible gases such as natural gas, LPG, coal gas.

Parameters:

Model	MC227D
Sensor Type	Catalytic Type
Standard Encapsulation	Plastic base & metal cap
Working voltage(V)	2.5±0.1
Working current(mA)	150±10
Sensitivity (mV)	20%LEL CH4
20%LEL C3H8	10～30
Linearity	≤5%
Measuring range(%LEL)	0～100
Response Time (T90)	≤10s
Recovery Time (T90)	≤30s
Working Environment	-40～+70℃ <95%RH
Storage Environment	-25～+70℃ <95%RH
Lifespan	5 years

Sensitivity and Response Feature

Changing of output signal at different temperature

Changing of output signal at different humidity

Changing of output signal with different voltage supplying

Long-term Stability
The drift in air per year is within ±2mV, in 20%LEL C3H8 is within ±5mV. For a short period storage (in 2 weeks), the sensor need be galvanical continuously for 8 hours to reach stability. For long period storage (one year), it need 48 hours.

Cautions

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 H2 S, 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.
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.
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 a 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.
Usage suggestions
3.1 Pins connection
When the sensor is connecting to the circuit, Pin1 connects to positive pole and Pin3 connects to negative pole. Connects Pin2 to Pin4 as output signal. The part with “D” mark on the sensor bottom is the detection one, the other part with “C” mark is the compensation one. 3.2 Soldering
For sensor, handmade welding is optimal way. The welding conditions as follow:
● Soldering flux: Rosin soldering flux contains least chlorine
● Homothermal soldering iron
● Temperature：＜350℃
● Time：less than 5 seconds