Semiconductor gas sensors usage Info

Semiconductor Gas Sensors usage Info

1 Following conditions must be prohibited

1.1  Exposed to organic silicon steam               
      Organic silicon steam cause sensors invalid, sensors must be avoid exposing to silicon bond, fixature, silicon latex, putty or plastic contain silicon environment
1.2  High Corrosive gas
       If the sensors exposed to high concentration corrosive gas (such as H2Sz, 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 fluorin. 
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’surface, otherwise sensor would lose sensitivity.      
1.6 Applied voltage higher
      Applied voltage on sensor should not be higher than stipulated value, otherwise it cause down-line or heater damaged, and bring on sensors’ sensitivity characteristic changed badly.
1.7 Voltage on wrong pins
      For 6 pins sensor, if apply voltage on 1、3 pins or 4、6 pins, it will make lead broken, and without signal when apply on 2、4 pins

2 Following conditions must be avoided
2.1 Water Condensation
      Indoor conditions, slight water condensation will effect sensors performance lightly. However, if water condensation on sensors surface and keep a certain period, sensor’ sensitivity  will be decreased.
2.2 Used in high gas concentration 
     No matter the sensor is electrified or not, if long time placed in high gas concentration, if will affect sensors characteristic.                                               
2.3 Long time storage
     The sensors resistance produce reversible drift if it’s stored for long time without electrify, this drift is related with storage conditions. Sensors should be stored in airproof without silicon gel bag with clean air. For the sensors with long time storage but no electrify, they need long aging time for stbility before using.

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 effect the sensors performance badly.

2.5 Vibration
      Continual vibration will result in sensors down-lead response then repture. 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
     For sensor, handmade welding is optimal way. If use wave crest welding should meet the following conditions:
  2.7.1  Soldering flux: Rosin soldering flux contains least chlorine
  2.7.2  Speed: 1-2 Meter/ Minute
  2.7.3  Warm-up temperature：100±20℃
  2.7.4  Welding temperature：250±10℃
  2.7.5  1 time pass wave crest welding machine

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