Peristaltic Dosing Pump The HI981413 has a powerful built-in peristaltic chemical feed pump that utilizes a stepper motor which does not have any gears or brushes to wear out. This design provides for a long life and little maintenance. Quick Connect Probe Input The Quick Connect DIN connector creates a waterproof seal with the controller making it ideal for reducing electrical noise issues with the connection caused by humid environments. Nutrient Level/Flow Switch Input The HI981413 allows for a connection to an optional level controller or flow switch. This input can be used to disable the dosing pump when there is no chemical left in the reservoir tank or there is no flow due to the pump being turned off. Adjustable Flow Rate The flow rate from the dosing pumps is adjustable from 0.5 to 3.5L/h. Larger bodies of water require more chemical to be dosed than smaller ones in per unit of time. The adjustable flow rate, like the proportional band, allows for better control in maintaining a desired set point. Programmable Alarm System Enables or disables the low and high-level alarms. When an alarm is activated, all dosing will stop. For added safety, the alarm system also offers overdosing protection in that if the set point value is not corrected within a programmed time interval then the meter will go into alarm status. Multicolored LCD Display The HI981413 features a multi-colored LCD that provides for a quick way to see the status of the controller. If in control mode and operating as intended the display will be green. If control is not enabled then the display will be yellow; while in an alarm state the display flashes red. Automatic Proportional Pump Control The peristaltic dosing pump can be controlled by simple on/off or more advanced proportional control which helps prevent overshooting of the set point. When using proportional control the flow rate that is programmed, will be impacted by the proportional band used. The closer the reading is to the set point the longer it takes for the peristaltic pump to complete one revolution. If the reading is outside the proportional band then the amount of time it takes to complete one revolution is based on the flow rate programmed. For example, a controller is programmed to have a set point of 1.50 mS/cm with a 0.30 mS/cm proportional band and the flow rate at 1 L/h. Any reading below 1.20 mS/cm will cause the dosing of stock fertilizer to be at 1 L/h. If the reading is at 1.35 mS/cm, which is 1/2 of the band, then the dosing pump will run at half speed or deliver 0.5 L/h of chemical. The closer the reading is to the set point the longer it takes for the pump to complete one rotation. This allows for very fine control of the EC/TDS value desired. Features 15 Process Instrumentation 15.39 www.hannainst.com | controllers
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