Winsen GM-602B MEMS Hydrogen Sulfide H2SGas Sensor User Manual

Winsen GM-602B MEMS Hydrogen Sulfide H2SGas Sensor

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

GM-602B MEMS H2S Gas Sensor

Product description
MEMS H2S gas sensor is using MEMS micro-fabrication hot plate on a Si substrate base, gas-sensitive materials used in the clean air with low conductivity metal oxide semiconductor material. When the sensor exposed to gas atmosphere, the conductivity is changing as the detected gas concentration in the air. The higher the concentration of the gas, the higher the conductivity. Use simple circuit can convert the change of conductivity of the gas concentration corresponding to the output signal.

Character
MEMS technology, Strong construction High sensitivity to H2S gases Small sizes and low power consumption Fast response and resume Simple drive circuit, Long lifespan

Application
Portable and fixed type hydrogen sulfide monitor, and H2S detector

Parameters Stable1.

Standard Circuit Conditions

| Loop Voltage| VC| ≤24V DC
Heater Voltage| VH| 1.9V±0.1V AC or DC
Load Resistance| RL| Adjustable

Sensor character under standard test conditions

| Heater Resistance| RH| 80Ω±20Ω（room temperature）
Heater consumption| PH| ≤40mW
sensitive materials resistance| RS| 1KΩ～30KΩ(in 50ppm H2S )
Sensitivity| S| R0(in air)/Rs(in 50ppm H2S)≥3
Concentration Slope| α| ≤0.6(R200ppm/R50ppmH2S )
Standard test conditions| Temp. Humidity| 20℃±2℃；55%±5%RH
Standard test circuit| VH:1.9V±0.1V；VC :5.0V±0.1V

Sensor Structure Diagram

Basic Circuit

Instructions : The above fig is the basic test circuit of GM-602B.The sensor requires two voltage inputs: heater voltage (VH) and circuit voltage (VC). VH is used to supply specific working temperature to the sensor and it can adopt DC or AC power. Vout is the voltage of load resistance RL which is in series with sensor. Vc supplies the detect voltage to load resistance RL and it should adopt DC power.

Sensor’s Characteristics:

Rs means resistance in target gas with different  concentration, R0 means resistance of sensor inclean air. All tests are finished under standard test conditions. Rs means resistance of sensor in 50ppm hydrogen sulfide (H2S) under different temp. and humidity. Rso means resistance of the sensor in 50ppm H2S under 20℃/55%RH.

Voltage output(V)

The output in above Fig is the voltage of RL which is in series with sensor. All tests are finished under standard test conditions and the test gas is 50ppm H2S. The output in above Fig is the voltage of RL which is in series with sensor. All tests are finished under standard test conditions

Test is finished in standard test condition, the abscissa is observing time and the ordinate is voltage output of RL.

Instructions

1. Preheating time
   Sensor’s resistance may drift reversibly after long-term storage without power. It need to preheat the sensor to reach inside chemical equilibrium. Preheating voltage is same with heating voltage VH. The suggested preheating time as follow: Storage Time| Suggested aging time
   ---|---
   Less than one month| No less than 48 hours
   1 ~ 6 months| No less than 72 hours
   More than six months| No less than 168 hours
2. Calibration
   Sensor’s accuracy is effected by many factors such as reference resistance’s difference, the sensitivity difference, temperature, humidity, interfering gases, preheating time, the relationship between input and output is not linear, hysteretic and non-repetitive. For absolute concentration measurement, they need regular calibration (one-point calibration / multi-points calibration for full scale) to ensure that the measuring value is accurate. For relative measurement calibration is not required.

Following conditions must be prohibited

1. Exposed to organic silicon steam
   Sensing material will lose sensitivity and never recover if the sensor absorbs organic silicon steam. Sensors must be avoid exposing to silicon bond, fixature, silicon latex, putty or plastic contain silicon environment.

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.

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.

4. Touch water
   Sensitivity of the sensors will be reduced when spattered or dipped in water.

5. Freezing
   Do avoid icing on sensor’s surface, otherwise sensing material will be broken and lost sensitivity.

6. Applied voltage
   Applied voltage on sensor should not be higher than 120mW, it will cause irreversible heater damaged, also hurt from static, so anti-static precautions should be taken when touching sensors.

Following conditions must be avoided

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. 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.

3. Long time exposed to extreme 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.

4. 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.

5. Concussion
   If sensors meet strong concussion, it may lead its lead wire disconnected.

6. Soldering
   Soldering flux: Rosin soldering flux contains least chlorine and safeguard procedures.

If disobey the above using terms, sensors sensitivity will be reduced.

Environmental protection
This product complies with the current ROHS directive and does not contain ten chemicals subject to environmental restrictions.

Packing Method
The surface of MEMS sensor is pasted with special protective film to prevent the influence of dust, water, atmosphere and high temperature. The protective film can be removed after welding. Braided packaging is adopted, and other packaging methods can also be provided according to customer requirements.

• Tel : 86-371-67169097/67169670
• Fax : 86-371-60932988
• Email: sales@winsensor.com

References

• Winsen Gas Sensor_CO2 Sensor_Air Quality Sensor_Dust Sensor_CO Sensor-Winsen Electronics

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