Test particle size: 0.3μm/2.5μm/10.0μm Light source: Semiconductor lasers Accuracy:± 5% Temperature range:0~50℃ /32~122℉ Accuracy: ± 5% Humidity range:0~100%RH Accuracy:±2% RH Display:320*240 2.8in LCD display Counting efficiency:100±10%@0.5μm Sampling Custom(1s~ 59min. 59s) Sampling frequency:1~99/Continuous Alarm levels:1~100,000(FED209E Standard) 2~9(ISO14464-1Standard) Test mode :Single/repeat/continuous/timer/Average Data Storage: 999 Power: 9 V DC battery (not included). Operating environment: 5~45℃, <90% RH Storage environment:-20~60℃, < 90% RH