Gas Detection

  • Dynamic range sensors

Dynamic range sensors

May 16 2018 Read 658 Times

The theoretical base of IR gas detection is represented by the Beer-Lambert Law, a basic law of physics relating the attenuation of light to the properties of the material through which the light is travelling.

According to it, the strength of an NDIR sensor signal is proportional to: the intensity of the beam of IR light; the specific absorbance characteristics of the molecules of the gas being measured; the length of the optical path (the distance traveled by the light through the sensing chamber); the actual concentration of the gas being measured.

While at low concentrations the absorbance curve is almost linear, the Law is not obeyed at high concentrations - as shown as example for the Methane response curve diagram below (solid line).

This means that a fitting for the response curve made for low-range concentrations (dotted line) would significantly differ from the actual response at higher ranges, leading to very inaccurate measurements. By adhering more to the higher volume response portion of the curve (dashed line), low-volume reading would be vastly underestimated.

To meet the necessities of customers expecting dependable detection accuracy over a full 0-100% range, N.E.T. has introduced his DYNAMIC RANGE technology. The sensor divides the full 100% range in three different segments and for each one of them utilises a different fitting curve. A proprietary algorithm handles hysteresis when working at the conjunction of the three ranges. This ensures excellent adherence to the actual non-linear response - and unprecedented accuracy at both low and high volumes.

The set of fitting coefficients for each range segment is individually determined for each sensor through the entire temperature range by an automated procedure in N.E.T.’s laboratories.

DYNAMIC RANGE algorithms are made possible by N.E.T.’s MICROPROCESSOR TECHNOLOGY.

Reader comments

Do you like or dislike what you have read? Why not post a comment to tell others / the manufacturer and our Editor what you think. To leave comments please complete the form below. Providing the content is approved, your comment will be on screen in less than 24 hours. Leaving comments on product information and articles can assist with future editorial and article content. Post questions, thoughts or simply whether you like the content.

Post a Comment

Digital Edition

International Environmental Technology April 2019

April 2019

In This Edition Business News - New appointment to boost noise and vibration specialists - Restek and LECO collaborate in worldwide supply agreement - Evonik catalyst in the life support sy...

View all digital editions


64th ISA Analysis Division Symposium

May 05 2019 Galveston, TX, USA

Ozwater 2019

May 07 2019 Melbourne, Australia


May 15 2019 Seoul, South Korea

FlowExpo 2019

May 16 2019 Guangzhou, China

AIHce 2019

May 20 2019 Minneapolis, MN, USA

View all events