Hanna Instruments Pool Line Professional Waterproof Portable pH/ ORP Meter

HI981914 Pool Line Professional Waterproof Portable pH/ORP meter is a highly accurate that is equivalent to meters used in laboratories. HI 981914 offers many advanced features from a large dot matrix LCD that provides for an intuitive user interface in the operation of the meter, log on demand for storing readings, USB port for transferring data, GLP data for tracking calibration data, and Hanna's exclusive CAL Check for pH calibration diagnostics. During the calibration process the meter analyzes the mV signal being generated and provides warnings to whether the probe needs to be cleaned or of the buffer is contaminated. After calibration the meter displays the overall health of the pH electrode as a percentage and is based on both the offset (mV value in pH 7 buffer) and slope (mV difference from pH 7 to pH 4/10) characteristics.
The HI981914 uses pH and ORP probes with a BNC connector. The BNC connector can be used with process probes for evaluation of their performance. For pH it is possible to set the meter to a "default" calibration that resets the meter to the ideal mV response for a pH probe. When this is done then it is possible to connect a pH probe and perform a calibration. CAL-Check will provide the diagnostic messages to indicate potential problems. For example if the meter display condition at 10% or flashing then it would be recommended to clean the probe. If after cleaning the probe and the condition remains low after a subsequent calibration then this would be an indicator that the probe is reaching it end of life. The probe characteristics can be reviewed using the GLP feature. An acceptable offset value is +/-30 mV and the slope should be better than 90%. Values greater than +/- 60 mV or a slope less than 85% are indicators that the probe needs to be replaced in the near future to avoid a service calls due to probe failure or loss of control parameters.
For ORP probes the mV function and a 470 mV test solution is used to check the performance of an ORP electrode. A probe not reading correctly should be cleaned and the platinum sensor surface polished. If an acceptable value is not obtained then the ORP probe should be replaced.
The HI981914 can be used for process calibration as well in which the measurement is made with a calibrated pH probe or a measurement by an ORP probe and the value entered into a process controller to match the measured values.