PORTABLE PH & ORP METER WITH DATA STORAGE Large LCD screen with controllable white backlight. The built-in microprocessor chip has Intelligent functions such as auto calibration, ATC, data storage, function settings, auto diagnosis, auto power off, and under voltage prompt, etc. Auto recognition of 25 buffers with three kinds of options: Europe & USA, NIST and China. Support 1, 2, 3 point calibration. Can set up pH measurement modes of high purity water and ammonia added pure water. Grade IP57 and equipped with suitcase for outdoor purpose.