â·ÃÊͺ¶ÒÁÃÒ¤Ò testo 535 CO2 measuring instrument with fixed probe incl. battery and calibration protocol Testo 535 CO2 measuring instrument with fixed probe incl. battery and calibration protocol testo 535, the efficient CO2 measuring instrument for measuring indoor air quality. Bad air quality in rooms can lead to tiredness, lack of concentration and illness (Sick Building Syndrome) due to high CO2 concentration (greater than 1000 ppm) Long-term monitoring based on maximum and mean calculation Long-term stable 2 channel infrared sensor Highly accurate, highly efficient Repeated calibration is unnecessary LCD, 2 lines Storage temperature -20 to +70 °C Operating temperature 0 to +50 °C Battery type 9V block battery Battery life 6 h Weight 300 g Dimensions 190 x 57 x 42 mm Material/Housing ABS Probe type CO2 Meas. Range 0 to +9999 ppm CO2 Accuracy ±(50 ppm CO2 ±2% of mv) (0 to +5000 ppm CO2) ±(100 ppm CO2 ±3% of mv) (+5001 to +9999 ppm CO2) Resolution 1 ppm CO2 Carbon dioxide Meter CO2 Meter Gas Leak Detector Gas Meter Testo Testo 535 à¤Ã×èͧµÃǨ¨Ñºá¡êÊÃÑèÇ à¤Ã×èͧÇÑ´¡êÒ«¤ÒÃìºÍ¹ä´ÍÍ¡ä«´ì à¤Ã×èͧÇÑ´á¡êÊ