Carbon Dioxide Point Sensor

High-Sensitivity, Fast-Response


SDL has developed a field-deployable, compact, highly sensitive, and battery-operated CO2 sensor for atmospheric monitoring. It outperforms the current state-of-the-art instrument (Vaisala Field Check Adapter) in both sensitivity (160 ppm vs 0.5 ppm) and measurement response time (20 sec vs 250 msec).

Concept of Operation

Wavelength modulation spectroscopy

  • Modulate a 2μm, SLM, VCSEL at 10 kHz for lock-in detection
  • Sample through a Herriott configured multi-pass cell
  • Detect with InGaAs detector
  • Convert signal to ppm vs. time using CO2 calibration curve
  • Transmit data wirelessly from sensor to laptop controller

Performance Specifications

Parameters CO2 sensors
Laser Frequency 2 μm
Sensitivity < 540 ppb
Measurement Response Time 250 ms
Optical Path-length 3.5 m width /11.4 cm cavity length
Dimensions 23.9 x 16 x 8.9 cm
Wireless Transmission Range 45 m (indoor), 124 m (outdoor)
Weight < 4 lbs
Battery Pack/Battery Life 3.7 V, 10 amps, Li-ion; 20 hrs
1695 North