Designing drift-free and reliable NDIR gas sensors using modulated infrared sources
Axetris IR sources are based on the proprietary thin film technology from Axetris, and deliver exceptional performance when electrically modulated in the 5-100 Hz range. This feature can help NDIR gas sensor designers achieve drift-free operation, combined with increased reliability and lifetime. Here we present qualitative conclusions (see table) based on multiple years of internal performance testing.
Correcting baseline drift and achieving quicker warm-up time
In a modulated IR source, the IR intensity oscillates between the “high” (on) and “low” (off) values. This ratio (so-called “modulation depth”) represents the usable light intensity for gas concentration detection. Compared to an IR source powered in DC mode, the final (constant) usable light intensity is reached faster. Thanks to the proprietary thin film technology from Axetris - which enables a very quick response time of the emitting membrane - the Axetris IR source achieves very high modulation depths even at high modulation frequencies (10-100 Hz). Combined with advances in infrared detector technology (typically used detector types: pyroelectric or photodetectors), which offer ever-quicker detector response times, this feature can be used to design NDIR gas sensors with quicker warm-up time and drift-free operation.
Increased Reliability and Lifetime
Axetris IR sources are based on a highly stable and reliable black platinum emitting membrane, offering extremely long lifetimes (>10 years MTTF when driven in recommended limits). In addition, modulated drive modes further increase the reliability and lifetime of the IR source by decreasing effective “on-time”, whereby the ageing process is decelerated.
Read more about Axetris IR sources for NDIR gas detection and monitoring applications.