Features: Easy to use and easy to operate. Low power, low voltage, dry battery protection, long life of 10 years. Formaldehyde has nowhere to hide, multi-layer filtration anti-interference, anti-false alarm. Real-time detection, at a glance, beautiful design, simple operation, the values are clear at a glance. Efficient constant temperature detection, which can detect the temperature of the sensor with the change of temperature difference. Overcome the impact of large temperature differences on detection accuracy. Specifications: Condition:100% New Color: White Size: Approx.140*62*25mm/5.5*2.4*1.0in Weight: Approx. 131g/4.6oz Testing items: formaldehyde and TVOC (comprehensive pollutants) Sampling method: diffusion acquisition Detection principle: principle of semiconductor gas sensor Detection range: formaldehyde: 0.000-1.999mg/m3 TVOC: 0.000-1.999mg/m3 Display mode: LED high-definition backlit display Concentration unit: mg/m3 Storage temperature: -20 C -70 C Detection temperature: -20 C -70 C Battery: 2*AA Battery(Not included) (when the battery is low, the red light will flash continuously, replace the battery) Detection time: 5-10 minutes Instructions: 1. Power on: Press and hold the power button for 1 second, and then start the tone after hearing a tone. 2. Shutdown: Press and hold the power button for 3 seconds, and then turn off after hearing a tone. 3. Preheating: After power on, there will be an automatic countdown of 200 seconds on each LED screen. After the end, it will be placed for about 5 minutes (the instrument value is 0 or close to 0). Press and hold the M button for 3 seconds to get the value. Value success 4. After the value is successful, take the instrument directly to the room for testing (put the instrument in the test environment for about 5 minutes to read) 5.HCHO (formaldehyde): standard 0.10mg/m3, TVOC: standard 0.60.10mg/m3 6. The formaldehyde over-standard indicator changes from green to red. When the formaldehyde is seriously exceeded (greater than 0.3mg/m), the buzzer alarm Package List: 1*Formaldehyde Tester1Easy to use and easy to operate. 2Low power, low voltage, dry battery protection, long life of 10 years. 3Formaldehyde has nowhere to hide, multi-layer filtration anti-interference, anti-false alarm. 4Real-time detection, at a glance, beautiful design, simple operation, the values are clear at a glance. 5Efficient constant temperature detection, which can detect the temperature of the sensor with the change of temperature difference. Overcome the impact of large temperature differences on detection accuracy.