The C500 mainstream ETCO2 sensor is a smart option for ETCO2 measurement. It just needs 3 seconds to warm up. C500 can recognize all kinds of adapters, no matter new or old adapters. Even if the adapter is dewing for moisture, C500 still can get the accurate CO2 values. The C500 is designed specifically for mainstream measurement of CO2 using sophisticated infrared absorption spectroscopy. The measurements are taken at the patient airway at a sampling frequency of 100 Hz, so response is faster and there is less chance of erroneous, artifact data.