Extech RH390 Digital Psychrometers; Type: Precision Psychrometer; Minimum Dew Point (F): -22.0; Maximum Dew Point (F): 212; Minimum Humidity: 0; Maximum Humidity: 100; Maximum Temperature: 140.0 0C; 140.0 0F; 140.0 0; Accuracy Degree (C): 2.0; Accura