The Extech SDL100 pH/ORP Meter, an SD Logger Series meter. This meter displays and stores pH (from 0 to 14.00pH) and ORP (±1999mV) readings. A temperature probe (supplied) can be inserted to the meter to provide automatic temperature compensation. Logged data readings are stored on an SD card for transfer to a PC. In addition, an RS232 port allows data streaming to a PC. This meter is shipped fully tested and calibrated and, with proper use, will provide years of reliable service.