... 50 Hz and 60 Hz. 2.The altitude shall not exceed 3500m. 3.Ambient temperature : -20°C~+70°C,Relative humidity:≤95% 4 ... explosive gas,corrosive gas,and conductive dust. 9.As resistor is heating element,when use it ,the temperature will rise highly,so ... location. 8.whether need to add the grounding record and controlling equipments of temperature and humidity. If have any question please contact with us ...