The CDE and CWE are non‑dispersive infrared (NDIR) sensors designed for measuring environmental CO2 concentration in ventilation systems and indoor living spaces. Their measurement range of 0 to 2000 ppm makes them compliant with ASHRAE and other standards for ventilation control The CWE/CDE Series provides a user‑selectable 4 to 20mA or 0 to 10Vdc output for versatility.Microprocessor‑based digital electronics and a unique self‑calibration algorithm improves long‑term stability and accuracy.