KAL-D Flow Switch
The KAL-D series combines the features of our legendary KAL-K thermal flow switch with a compact size. The KAL-D uses the calorimetric principle to monitor the flowrate of non-viscous water-based liquids. The sensor tip is heated to a few degrees above the liquid temperature. As the liquid flows across the tip, it is cooled by the liquid.
The amount of cooling is proportional to liquid velocity. The liquid velocity is compared to the setpoint which is field-adjustable by the user. A transistor switch is activated when the flow setpoint is reached. The KAL-D series has a smooth measuring probe with no moving parts making it exceptionally reliable and insensitive to dirt and solids. The insertion type probe allows for flow monitoring with minimal system pressure loss.
Microprocessor-Based Temperature Compensation
The KAL-D series achieves superior compensation for changes in liquid temperature during the measuring cycle by use of a microcontroller. This method of temperature compensation allows for very precise correction of flow measurement when liquid temperature changes occur.
Diagram shows typical electrical wiring for the KAL-D configured as either a NPN or PNP transistor switch. The transistor switch output is configured as either an NPN or PNP open collector at the factory, based on the order code. It is not switchable from NPN to PNP or vice versa in the field. The wire colors listed in Diagram 4.2 correspond to the color codes on the mating micro- DC plug with cable (sold separately).
DC Ground switched to pin 4 when switch is activated. High impedance at pin 4 when switch is not activated.
24 VDC is switched to pin 4 when switch is activated. High impedance at pin 4 when switch is not activated.