Globally, people are more aware of their surrounding environment and the potential risks involved from our environmental impact. One key factor ensuring ecological safety is monitoring accidental gas leaks, which can pose huge threats to properties and the environment and even lead to fatalities. Numerous measures and regulations have been implemented to prevent tragedies from happening.
Sensors have been proposed to detect and monitor toxic and combustible gases for general and industrial use. Manufacturers have developed various kinds of detection principles; for example, semiconductor gas sensors, electrochemical gas sensors, non-dispersive infrared (NDIR) gas sensors, catalytic gas sensors, thermal conductivity gas sensors, magnetic gas sensors, and so on. Each type of sensor has advantages and disadvantages, but NDIR sensors stand out due to their ability to detect a wider range of gases. It is a high-precision, high-stability, low-maintenance, and long-term option.
Non-dispersive infrared is the gas concentration measurement method that uses each gas's unique absorption wavelength range. IR light is absorbed by the target gas and this absorption is quantitatively described by the Beer-Lambert law:
I= I0 e-εcL (1)
I and I0 are the light intensity signals measured in the presence and absence of the target gas, respectively.
ε is the molar attenuation coefficient of the target gas, c is the target gas concentration, and L is the length of the light chamber. From Equation (1), one can calculate the transmission T as :
T= I/I0 = e-εcL (2)
The gas concentration can be determined by measuring the changes in transmission from the source to the detector.
The main components of an NDIR sensor are an infrared (IR) source, a sample chamber, a light filter, and an infrared detector. One of the important factors for measuring gas concentration using the NDIR method is an infrared source with higher infrared output.
Incandescent lamp option: Lower electricity conversion to light efficiency is often considered a disadvantage of incandescent lamps compared with LEDs. However, for NDIR sensors infrared output is more critical for measurement accuracy, and the incandescent lamp can provide higher output in the mid-infrared wavelength range. As a broadband lamp source, incandescent lamps cover a wider wavelength range (from mid-infrared to visible light region). This feature makes building a system with a single infrared source possible.
LED lamp option: LEDs are small and compact, making them suitable for integration into portable or handheld gas detectors. Another advantage of LED is lower power consumption, which can prolong battery life in handheld gas detectors.
Lightech Electronics is the leading incandescent bulb business model in Thailand. We have incorporated our experience in automotive and aviation lighting to produce highly accurate subminiature lamps. Our NDIR sensor lamp can be customized to meet your requirements. Various filament and glass types with customizable shapes and sizes can be produced for different sensor models.
Broadband Lamp Source Customization
Voltage range: 2.7v ~18v
Diameter of glass envelope: 2.3 ~3 mm
Candle power output: 0.15
Life span: 10,000~100,000 hours depending on lamp design
Application of Lightech Electronic NDIR lamp
● Alcohol detection
● Automotive exhaust gas measurement
● CO2 measurement
● Gas/fire detection
● Monitoring environment (office, interior of vehicle, etc.)
● Refrigerant gas and greenhouse gas measurement
Example of gas detection system with light source
