New optoelectronic devices for the Mid-Infrared spectral range open completely new possibilities for portable sensors creation. Using Mid-infrared LED-PD optopairs allows developing an instrument that is smaller, less expensive and versatile.

Methane detection

Methane is produced by many natural and human-influenced sources. There are several different techniques of methane detection. We offer method of mid-infrared optical absorption based on LED-PD optopair.
Methane has the main absorption band at 3200-3400 nm. Weaker absorption bands that can be used for detection are located around 2300 nm and 1650 nm (the data are taken from HITRAN Catalogue). So, we recommend using:
- for compact measuring cells and/or for detection of low CH4 concentrations: light emitting diode Lms34LED and Lms36PD series photodiode;
- for long-path measuring cells and/or for high CH4 concentration detection: light emitting diode Lms23LED and Lms24PD series photodiode.

Spectra of LEDs and PDs for methane detection:


Advantages of our devices:
✔  Possibility to arrange a compact design of an optical cell thanks to compact size of the LED chip – 0.35 × 0.35 mm
✔  No need of using additional optical filters – LED emission band width is comparable to absorption band width of CH4
✔  Low power consumption (<1 mW)
✔  Short response time (10‒50 ns)
✔  Possibility to achieve modulation ranges of up to 100 MHz
✔  Operation temperatures up to +150°C
✔  Lifetime of 80 000 hours


LED-PD based Evaluation systems for methane
For quick start we offer out-of-the-box solutions that can be launched with minimal effort – evaluation systems:
MDK evaluation kit with modular design that includes:
- Light emitting diode Lms34LED (other LED is available) with an LED driver
- Photodiode Lms36PD (other PD is available) with a preamplifier
- SDM synchronous detector
- Any additional component(s) can be added by request

NEW MDK-c evaluation kit with modular design that includes:
- Light emitting diode Lms34LED-CG (LED with a special glass covering) with an LED driver
- Photodiode Lms36PD-CG (PD with a special glass covering) with a preamplifier
- SDM synchronous detector
- Any additional component(s) can be added by request

NEW MDS-5 system with a compact optical cell that incorporates an LED and a photodiode with a special glass covering. It includes all the needed circuitry for quick setup: LED driver, photodiode preamplifier, synchronous detector.

NEW MDS-4 methane sensor module – a low-cost “on-board” system with very low power consumption that includes a compact optical cell and electronics for LED power supply and PD signal amplification all-in-one.

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