Hanna Instruments HI504224-1 On/Off and PID pH/ORP Digital Process Controller with 2 Set-Point and 2 Analog Output, 115V

The measurement configuration settings and control of pH and ORP are saved separately and permits users to switch between pH and ORP without losing settings. The pH channel can be calibrated in 2 calibration points. The instrument has a full auto diagnostic procedure. Temperature is continuously monitored using a temperature sensor (Pt100 or Pt1000 type) with automatic temperature compensation of pH. Controller status is visible with LED's on the front panel and on LCD. The controllers logging feature can save up to 6000 samples pH/degree C or ORP and last 100 error, configuration, calibration and cleaning events. This information can accessible from a PC through RS485 and windows compatible software. The powerful software has graphing capabilities and can print graphs directly or can be saved as a bitmap. Data can be exported in common spreadsheet formats. The outputs can be connected to a recorder for the catalogging of process data (pH/mV and temperature). The hold function allows the user to stop the regulating action of the controller for programmable time periods. It is possible to activate the hold periods in correspondence to programmed operations, such as plant maintenance and cleaning procedures. Hanna's exclusive fail safe alarm system protects against problems caused by power supply failure or signal interruption, which are typical risks in industrial environments. The system acts both on a hardware and a software level. The alarm relay functions in a normally closed condition, and is tripped when there is a power failure if, for example, the power cable is accidentally cut. This function is very important in industrial plants where alarms are usually not activated if there is a power supply interruption, which can cause serious damage due to a loss of control of the process plant. At the software level, the fail safe function activates an alarm in case of abnormal circumstances, for example if the dosing contacts remain closed for an excessive period.