Kobold Kal-K Specifications

Thermal Flow Switch

for Water-Based Liquids

measuring

•

monitoring

•

analyzing

KAL-K

• Flow Velocities from 0.04...2 m/s

• T

: 250 °F, P

max

: 1450 PSIG

max

• NPT and 3-A Compliant Sanitary Fittings

• No Moving Parts

• Intelligent Temperature Compensation

• Extremely Low Pressure Loss

• Easy to Operate

• Insensitive to Dirt

KOBOLD companies worldwide:

ARGENTINA, AUSTRALIA, AUSTRIA, BELGIUM, BULGARIA, CANADA, CHILE, CHINA, COLOMBIA,
CZECH REPUBLIC, EGYPT, FRANCE, GERMANY, HUNGARY, INDIA, INDONESIA, ITALY, MALAYSIA,
MEXICO, NETHERLANDS, PERU, POLAND, REPUBLIC OF KOREA, ROMANIA, SINGAPORE, SPAIN,
SWITZERLAND, TAIWAN, THAILAND, TUNISIA, TURKEY, UNITED KINGDOM, USA, VIETNAM

05/07-15-2019

KOBOLD Instruments, Inc.
1801 Parkway View Drive
Pittsburgh, PA 15205

Main Ofce:

1.800.998.1020

1.412.788.4890
[e-mail]
www.koboldusa.com

Temperatur (C)

0

80

2

Thermal Flow Switch Model KAL-K

Description

The KAL-K thermal flow switch utilizes KOBOLD’s temperature
compensating electronics. This compact, one-piece unit
provides reliable readings unaffected by temperature or physical
characteristics of non-viscous water-based liquids. This is made
possible through the use of state-of-the-art microprocessor
technology. The microprocessor can be field calibrated to both
the liquid properties and operating range in a simple, five minute
set-up procedure. This intelligence, coupled with a “no moving
parts” design, make the KAL a superior performer in virtually all
applications. The KAL-K is also offered in a 3-A compliant version.

The KAL-K incorporates an 8 segment bar-graph LED flow
trend indicator and one flow alarm setpoint. The setpoint is fully
configurable as NPN, PNP, normally open or normally closed.

Operation

The KAL design is based on the time proven calorimetric
principle. The sensor is internally heated to a few degrees above
the temperature of the media. Flow causes removal of heat from
the sensor, resulting in a cooling effect. The rate of cooling is a
measure of the flow velocity. The microprocessor based design
of the KAL distinguishes it from the competition. Full temperature
compensation of the flow rate is readily obtained through a simple,
one-time, calibration procedure. This assures elimination of flow
rate reading drift caused by temperature variations in the process
liquid.

KAL Timing - Heating and Measuring Cycle

Temperature Compensation

The KOBOLD KAL flow products use a microprocessor to
compensate for temperature changes through use of an internal
look-up table. End-users can easily adapt the equipment to the
requirements of their unique installations. Unlike conventional
calorimetric flow switches, the technically advanced design of the
KAL provides a flow reading which is unaffected by temperature.

Operating Behavior

1. At t=0, the probe temperature is recorded. This reading
represents the ambient liquid temperature.

Schaltpunktveränderung über Temperatur

2. Still at t=0, the KAL begins heating the probe.

3. At t=0.8 seconds, the heating cycle ends and the KAL begins
monitoring the probe temperature.

KAL-... with compensation

KAL-... mit Kompensation

4. At t=1.8 seconds, a temperature reading is taken and
compared to the t=0.8 second temperature. The rate of cooling

Schaltpunkt (m/s)

Switch point (m/s)

Standard without

Herkömmlich

compensation

ohne Kompensation

is calculated and compared to a Cooling Rate vs Flow Rate
table specific to the ambient temperature recorded at t=0.

5. 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 flow
reading is determined valid and passes through to the KAL
output. If the temperatures are not equal, the KAL waits

20 30

40

Temperature °C

50

60

70

another 5.6 sec, and Step 5 repeats.

2

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No responsibility taken for errors;

subject to change without prior notice.

Thermal Flow Switch Model KAL-K

Specifications

Switching Range: 0.04...2 m/s
Media: Water-Based Liquids (Water

Content at least 90%);
not Suitable for Oils or Fuels

Response Time
Typical: 5.6 seconds
Optional w/"F": 1.2 seconds
Fittings
Standard: 1/2" or 3/4" NPT
Sanitary: 1-1/2" Tri-Clamp®
Flow Trend Indicator: 8 Red LEDs
Temperature Rating
Operating: 32...250 °F
CIP: 280 °F (non-operating)
Maximum Pressure
Threaded: 1450 PSIG

Approximate Switch Points at Various Pipe Diameters

Sanitary: 600 PSIG or per Clamp Rating
Wetted Parts
Standard NPT: 304 SS
Optional NPT: 316-Ti SS

Sanitary: 316L SS
Housing
Standard: IP 65
Sanitary: IP 65
Power Requirements
Supply Voltage: 24 VDC ± 10%
Optional: 110 V
Current Draw: 300 mA Max.

AC

Switch Characteristics
Adjustment: By Potentiometer
Status Indicator: Bi-colored LED
24 VDC Units
Type: PNP or NPN, Open Collector
Switch Rating
DC Only: 400 mA at 24V
110 VAC Units:
Type: N/O Dry Contact
Switch Rating
AC Only: 5A at 240 V

Nominal ID

(inch)

1/2 0.08...4.0

3/4 0.2...9.0

1 0.4...16

1 1/4 0.5...25

1 1/2 0.8...36

2 1.3...64

2 1/2 2.0...100

3 3.0...140

Note:

The approximate flow ranges specified in the table above have
been calculated for each pipe diameter from the known flow
velocity range of the KAL. It must be noted that flow in pipes is
non-uniform across the pipe cross-section and approaches zero at
the pipe wall. This means that, in practice, the depth of installation
of the probe, the internal pipe diameter, and the flow profile of the
liquid in the pipe can interact to produce very significant deviations
from the flow ranges in this data sheet.

Range Water

(GPM)

Nominal ID

Range Water

(inch)

4 6.0...250

6 12...575

8 20...1025

10 35...1600

12 50...2300

16 85...4100

20 130...6400

(GPM)

DC Only: 0.2 A at 110V

For correct operation of the KAL-K thermal flow switch, the tip of the flow sensor must be located sufficiently into the flow stream of the

process to sense the liquid flow. Therefore it is very important to consider the sensor's insertion depth and how it is installed in the process

pipe. If the sensor tip is not adequately immersed into the flow stream, the sensor will not measure flow rate correctly, or worst case will not

detect any flow at all. Ideally for correct detection, we recommend the sensor tip be located at a distance from the pipe wall equal to 20% of

the internal cross-section diameter of the pipe. Note that NPT fittings are tapered, and consideration should be given to the fact that when

installed together, NPT mating fittings will not fully thread down to the bottom of the female connection.

KAL-K Order Details (Example: KAL-4315C)

Fitting

Model

(304 SS)

Model

(316-Ti SS)

1/2" NPT KAL-4215 KAL-4315 -

3/4" NPT - KAL-4320 -

1-1/2"

Tri-Clamp®

- - KAL-4340S

*specify probe length on your order (NPT models only)

No responsibility taken for errors;
subject to change without prior notice.

Model

(316 L SS)

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Options

..C = 1/2" NPT Conduit Electrical Connection

..EP = Extended Probe*

..F = Fast Response Time (24 VDC Units Only)

..K = N/C Switch Logic

..M12 = Plug Connector w/6 ft Cable for 24 VDC Units

..P03R = 110 VAC Version with Dry Contact

3

Dimensions

Standard Version

Thermal Flow Switch Model KAL-K

1/2" Model

3/4" Model

Sanitary Version

4

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No responsibility taken for errors;

subject to change without prior notice.