YT311 High Precision Digital Sound Level Meter Support Temperature and Humidity Measurement Feature: 1. High-Precision Measurement: Equipped with a highly sensitive condenser microphone, it offers a wide measuring range of 30–130 dB, accurately capturing subtle sound variations for everything from home environmental testing to industrial noise inspection. 2. AC Frequency Weighting for Dual Scenarios: Features interchangeable AC Weighting modes. Use A-weighting for human ear response simulation and C-weighting for mechanical noise analysis, providing scientific data for any application. 3. HD Backlight LCD Display: Features an HD LCD screen with a built-in backlight function, ensuring crystal-clear visibility of decibels, temperature, and humidity, whether you are working in bright sunlight or dark environments. 4. Ergonomic & Portable Design: Boasting a striking orange-and-black ergonomic design with non-slip side grips, it fits perfectly in one hand, allowing for effortless portable noise testing anytime, anywhere. 5. Multi-functional All-in-One Meter: More than just a decibel meter! It simultaneously displays ambient temperature and humidity, alongside practical functions like MAXMIN tracking and Data Hold for comprehensive environmental monitoring. Specifications: 1. Large HD FSTN display with full viewing angle; three-color backlight (green, yellow, red) 2. Sound level measurement range: 30–130 dBA, 30–130 dBC 3. Accuracy: ±1.5 dB (94 dB @ 1 kHz) 4. Frequency response: 30 Hz–8 kHz 5. Frequency weighting: A, C 6. Time weighting: FAST, SLOW 7. Sound level display via data bar 8. "OVER" range indicator 9. Temperature measurement range: -20–60°C -4–140°F (Accuracy: ±1°C ±2°F) 10. Humidity measurement range: 0.0%–99.9% RH (Accuracy: ±4% RH) 11. Features: Data hold, MAXMIN values, auto power-off (with disable option), low battery indicator, °C°F unit switching 12. Power supply: 3 x 1.5V AAA batteries (not included)