The APCA-370 is a device for continuous CO2 monitoring in ambient air. It uses cross modulation type non-dispersive infrared (NDIR) absorption method. This method employes one cell and one light source for both sample gas and reference gas what allows precise measurement without generation of zero-drift. Due to precise measurement and long term stability in continuous monitoring as well as its minimal maintenance requirements, this method has been a preferred method for monitoring the atmospheric pollution.
| Model | Ambient CO2 Monitor |
| Measurement target | Carbon dioxide (CO2) in ambient air |
| Measuring principle | Cross modulation type non-dispersive infrared absorption method |
| Range | 0 ppm to 500/1000 ppm |
| Minimum detection sensitivity | 0.5 ppm (2σ) |
| Reproducibility (repeating accuracy) | ±1.0% of the full scale |
| Linearity (readout error) | ±2.0% |
| Zero drift* | ±0.1 ppm/day ±2.0 ppm/week |
| Span drift* | ±2.0% of the full scale/day ±3.0% of the full scale/week |
| Response rate | 60 sec or shorter (T90 from the inlet) |
| Sample collection rate | Approximately 0.7 L/min |
| Display | Measured value, alarm, time, alarm history, calibration history, etc. |
| Alarms | Zero calibration, span calibration, etc. |
