1. Real time monitoring: Real time display of formaldehyde concentration, tvoc concentration, air humidity, and current time, fully understanding the air quality status. 2. Air quality assessment: Provides formaldehyde hazard assessment function to help users identify potential health risks in the air. 3. Historical data recording: Support historical data recording of formaldehyde concentration and tvoc concentration for better long-term air quality management. 4. Spatial average: Calculate the spatial average of formaldehyde and tvoc to help users evaluate air quality more accurately. 5. Formaldehyde removal calculator: Intelligently calculates formaldehyde removal time, cost, and required materials based on house area, house type, average formaldehyde content, and formaldehyde removal method. Alarm threshold setting: Users can set the alarm thresholds for formaldehyde and tvoc according to their needs. Once exceeded, the equipment immediately sound an alarm to indoor air safety. Calendar and time display: Display the current date, time, and humidity, providing convenient time management functions. Parameters: Product name:4 in 1 formaldehyde tester Product model:sfd-02 Screen material:2.4-inch tempered glass touch high-definition color screen Backlight: adjustable backlight brightness Charging method: usb type-c interface (5v/2a) Battery: 1000mah 1*lithium battery Language: chinese, english Formaldehyde parameters: Range: 0-2000 ppm Detection hardware: electrochemical sensor Preheating time: 5 seconds Tvoc parameters: Range: 0-10mg/m³ Testing hardware: Semiconductor sensors Preheating time: 120 seconds Classification of formaldehyde levels: Excellent: 0mg/m³ -0.08mg/m³ Good: 0.08mg/m³-0.1mg/m³ Mild pollution: 0.1mg/m³-0.2mg/m³ Moderate pollution: 0.2mg/m³-0.3mg/m³ Severe pollution: 0.3mg/m³and above Color:White Material:plastic Package Contents: 1 * Air Quality Monitor 1 * USB Cable 1 * Instructions in Chinese and English Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.