TSI 7545 IAQ-Calc Air Quality and Environmental Conditions Tester is designed to monitor indoor air quality (IAQ). The TSI 7545 features a sampling mode to record multiple point measurements, an advanced NDIR CO2 sensor for stable and accurate readings, data logging of up to 26,900 readings with 4 key measured parameters, and measuring of CO, CO2, temperature, humidity, dew point, web bulb temperature, and % outside air.