Key benefits — why you need this device Quickly monitors indoor air quality by measuring CO2 concentration together with temperature and humidity, helping you spot poor ventilation and take corrective action. Colorcoded backlight (green / yellow / red) gives an immediate visual warning of air quality at a glance. Simple, portable instrument that displays all critical data on a twoline LCD so you can assess conditions without scrolling or complex menus. What it does and how it helps Infrared CO2 sensing: uses an infrared sensor to detect CO2 levels reliably, enabling continuous monitoring of indoor air composition. Multiparameter measurement: shows CO2 concentration, ambient temperature, and relative humidity together so you can evaluate comfort and ventilation factors in one place. Temperature unit selection: lets you switch between Celsius (℃) and Fahrenheit (℉) to match your preference or regional standard. Color backlight alerts: green/yellow/red backlight provides immediate status feedback, simplifying decisions about ventilation or occupancy. Measurement HOLD: freezes the current reading on the display so you can record or reference a value without needing continuous observation. Automatic shutdown: conserves power by turning the instrument off automatically when not in use. Key features at a glance Infrared sensor for CO2 detection Simultaneous display of CO2, temperature, and humidity on a twoline LCD ℃ / ℉ temperature conversion Green / yellow / red backlight status indicator Measurement HOLD function Automatic shutdown for power saving Performance and usability Clear, twoline LCD layout shows CO2 on one line and temperature/humidity on the other for fast interpretation. Backlight color cues reduce the need to interpret numbers under pressure; useful when making quick ventilation decisions. Hold and autoshutdown functions improve practicality for spot checks and battery life management. Practical applications Home: Monitor CO2, temperature, and humidity in living rooms, nurseries, or home offices to improve comfort and reduce stuffy air during gatherings or remote work. Office and classroom: Use the backlight alert and combined readings to decide when to open windows or adjust HVAC to maintain a healthier indoor environment. Small commercial spaces: Quick spot checks in meeting rooms, waiting areas, or retail spaces to confirm adequate ventilation and comfortable conditions for customers and staff. What makes it stand out Consolidates three key indoorenvironment measurements into a single, easytoread instrument. Visual backlight prompts simplify decisionmaking without needing technical knowledge. Practical functions (HOLD and automatic shutdown) increase convenience and extend operational time between uses. Included functions (as specified) Infrared CO2 sensor CO2, temperature, and humidity measurement Temperature unit conversion (℃/℉) Twoline LCD showing CO2 and temperature/humidity Green/yellow/red backlight prompt Measurement HOLD Automatic shutdown If you need a straightforward tool to monitor indoor air quality and comfort indicators together—with immediate visual alerts and simple controls—this instrument provides the essential measurements and functions for everyday use.