Features
- No Moving Parts
- Switching Range 0.15...6.6 Ft/Sec.
- Max. Pressure 580 PSIG
- Max. Operating Temperature 176 °F
- Clean-In-Place to 250 °F
The KAL-D series combines the features of our legendary KAL-K
thermal fl ow switch with a compact size. The KAL-D uses the
calorimetric principle to monitor the fl owrate of non-viscous
water-based liquids. The sensor tip is heated to a few degrees
above the liquid temperature. As the liquid fl ows 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 fi eld-adjustable by the user. A transistor switch is
activated when the fl ow 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 fl ow 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 fl ow measurement when
liquid temperature changes occur.
Operating Behavior
- At t=0, the probe temperature is recorded. This reading represents the ambient liquid temperature.
- Still at t=0, the KAL begins heating the probe.
- At t=0.8 seconds, the heating cycle ends and the KAL begins monitoring the probe temperature.
- At t=1.8 seconds, a temperature reading is taken and compared to the t=0.8 second temperature.The rate of cooling is calculated and compared to a Cooling Rate vs Flow Rate table specifi c to the ambient
temperature recorded at t=0.
- The probe is allowed to cool until t=5.6 seconds. A temperature reading is taken and compared to the initial t=0 reading. If the temperatures are equal (or nearly so), the fl ow reading is determined valid and passes through to the KAL output. If the temperatures are not equal, the KAL waits another 5.6 sec, and Step 5
repeats.