ELT Sensor Technology

Gas Sensor NDIR Technology

Category	NDIR Sensors	Touch Sensors
Basics	Density is measured by assessing the optical absorbance of different types of gases absorbing infrared rays of specific wavelengths	Density is measure by assessing chemical changes that occur upon coming in contact with gas molecules
Types	Non-dispersive infrared type Photo-acoustictype	Semi-conduct type Solidelectrolytetype Electro-chemicaltype
Difference	Highly accurate by only detection of specific gases. Not influenced by other vapors and VOC gases. (Measure the energy difference before and after CO2 or CO absorbed its corresponding NDIR light frequency)	Not chosen for most application because its inaccuracy and unstability are get unbearably worse with time due to too limited and vulnerable technological ground.
Strength	Longevity over 15 years, high accuracy, no interference	small size and low price in sensor element
Weakness	Relatively larger size and higher price, however, the total price has shown a lower in long life time	Short life time in 2~5 year, low accuracy, interfered by other gases.
Evaluation	As the the average price of NDIR sensor get lower, the more touch sensors are getting replaced.

Principles of NDIR Gas Sensors

How does a non-dispersive infrared (NDIR) gas sensor work?

• Using the characteristics of different gas molecules absorb the corresponding specific wavelength band infrared rays,
  NDIR sensors measure the ratio of absorbed infrared rays and compute the density of gas
  (e.g. CO2 absorbs 4.26㎛ , and CO absorbs 4.64㎛)
• NDIR is contactless and highly accurate while having an extensive longevity.
• NDIR technologies have been recently applied in mass-producing low-cost CO2 sensors for everyday use.

Core technology of ELT NDIR sensor

• 1. Optical cavity design technology
  • Optimized Cavity Design Technique
  • Integration technology of maximum optical efficiency
  • Miniature Design technique
  • Low concentration gas detection technology
• 2. Circuit design technology
  • Low noise and stabilized circuit Fabrication Technology
  • Long term reliable sensor development Knowhow
• 3. Firmware and Evaluation Software
  • Sleeping mode control logic for Low power Consumption
  • Evaluation Board Control Software
  • Monitoring software and Communication Protocol
• 4. Sensor calibration technology
  • Temperature Effect Compensation and Correction Technology
  • Easy Sensor Management Technology
• 5. World’ 1st Class Sensor Development
  • Uncomparably accurate sensor Technology
  • World smallest, lightest, most favorable design
• 6. Low Power consumption design
  • Lowest current consumption design and control
  • Least Battery consumption design