The HI9813-6 portable meter features a large LCD which displays either pH, EC, TDS or temperature readings along with tutorial instructions. The pH readings are displayed with a 0.1 resolution and an accuracy of +/-0.1 pH while the EC and TDS readings are displayed with a 0.01 µS/cm and 1 ppm (mg/L) resolution and 2% full-scale accuracy. The EC range of the HI9813-6 is from 0.00 to 4.00 µS/cm and TDS is from 0 to 1999 ppm. The temperature correction coefficient (ß) is fixed at 2 %/oC and allows for automatic temperature compensated measurements of EC and TDS. The HI9813-6 is a basic pH/EC/TDS meter that is calibrated manually to a single point with the use of two trimmers. pH is calibrated to pH 7.01 while EC/TDS is calibrated to either 1.41 µS/cm (1413 µS/cm) or 1500 ppm. The LCD screen has battery life indicator as well as on-screen tutorial messages. The supplied HI1285-6 probe is a polypropylene body, amplified pH electrode with a built-in EC/TDS and temperature sensors. The amplifier for the pH electrode prevents interference from humidity and electriCalibration noise from common sources including from motors, ballasts or pumps. The HI9813-6 is a versatile meter for the agriculture, greenhouse and hydroponics industries. The HI9813-6 meter also offers the Calibration Check™ feature that alerts the user to a problem with a pH electrode. This feature is important for customers that calibrate only to pH 7.0; if there is a fracture on the pH glass of the electrode, the pH meter will always display pH 7.0 regardless of the solution being measured. This can be disastrous for the person that calibrates at pH 7.0 and takes readings of samples with an expected pH of 7.0. The user will never be aware that there is a problem with the electrode. This can result in inaccurate pH measurements, which for a greenhouse can affect the growth of the plants. Placing the HI1285-6 pH/EC electrode in the HI50021 Calibration Check™ solution helps users determine if the probe needs to be calibrated, cleaned or replaced. When the probe is placed in solution the user presses the “Check” key. The meter runs Calibration Check™ diagnostics and will display either “Probe is OK” or “Clean Probe and Calibrate”. If the reading is around pH 4.0 when the probe is placed in the solution then the probe is broken and needs to be replaced.