Kobold PAD Specifications

Heavy Duty

Differential Pressure

Transmitter

measuring

•

monitoring

•

analyzing

PAD

●● Span: 0.3" W.C. … 6" W.C. to 60 … 6000 PSIG

●● Static Pressure: Max. 4500 PSIG

●● t

: 248 °F

max

●● Process Connection: ½" NPT, ¼" NPT, or Various

Diaphragm Seals Available upon Request

●● Material: Stainless Steel

●● Various Outputs: 4 ... 20 mA or Frequency Output

●● Sensor Inputs: Differential, Gauge, or Absolute Pressure

●● Digital Communication with HART

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

01/03-18-2019

®

Protocol

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

Main Ofce:

1.412.788.2830

1.412.788.4890
[e-mail]
www.koboldusa.com

Heavy Duty Differential Pressure Transmitter Model PAD

Description

The KOBOLD Differential Pressure Transmitter model PAD
is a microprocessor based high performance transmitter.
It has flexible pressure calibration and output, automatic
compensation of ambient temperature and process variables,
configuration of various parameters, and communication with
HART® protocol. It measures pressure, flow and level by an
application method. All data is input, modified and stored in
EEPROM.

The KOBOLD Pressure Transmitter is also available as a flow
meter. The flowmeter model PAD-F has an added totalizing
function. It is able to check the flow rate and the totalizing flow.
It measures the flow rate by using differential pressure without
compensation for the temperature and static pressure. The
shape of the PAD-F is the same as the standard device.
Only the terminal block is different, since there are two more
terminals for the display of the pulse output.

Features

Superior Performance

●● High Reference Accuracy

●● Long-term Stability (0.125 % URL for 3 Years)

●● High Rangeability (100:1) for Range 4-0

Flexibility

●● Data Configuration with HART

●● Zero Point Adjustment

®

Communicator

Reliability

●● Continuous Self-diagnostic Function

●● Automatic Ambient Temperature Compensation

●● EEPROM Write Protection

●● Fail-mode Process Function

●● CE EMC Conformity Standards (EN 50081-2, EN 50082-2)

Transmitter Description

Electronics module

The Electronics module consists of a circuit board sealed in
an enclosure. There is an MCU module. an analog module,
an LCD module and a terminal module within the transmitter.
The MCU module acquires the digital value from the analog
module and applies correction coefficients selected from
EEPROM. The output section of the MCU module converts
the digital signal to a 4…20 mA output. The MCU module
communicates with the HART®-based communicator or
control system such as DCS. The power section of the MCU
module has a DC-to-DC power conversion circuit and an
input/output isolation circuit. The LCD module plugs into
the MCU module and displays the digital output in a user­configured unit.

Functional Block Diagram

High
Pressure

User-Selectable Input

• - D /- G /- H /- A

• Measuring Range

2

Sensor Part MCU Part

A/D Conversion

Capacitive

Sensor

EEPROM

Low

Pressure

Microprocessor

· Input Sensor Value

· Engineering Units

· Re–range (Zero / Span)

· Sensor Trimming

· Zero Point Adjustment

· DA Trimming

· Damping / Filtering

· Transfer Function

· LCD Engineering Mode

· Diagnostics

· Self Compensation

· Communications

· LCD Display

· Configuration Data

www.koboldusa.com

4~20mA

DAC

®

HART

HART® Protocol
with Host

No responsibility taken for errors;

subject to change without prior notice.

Heavy Duty Differential Pressure Transmitter Model PAD

Sensor Inputs

The models PAD-D, PAD-G, and PAD-H are available in a
capacitance type differential pressure sensor. It measures
differential and gauge pressure and is commonly used in flow
and level applications. Both sides in the capacitance sensor
transmit process pressure from the process isolators to the
sensor. The model PAD-A is also available in a piezoresistive
type absolute pressure sensor. The sensor module converts
the capacitance or the resistance to the digital value. The
MCU module calculates the process pressure based on the
digital value.

The sensor modules include the following features

• The software of the transmitter compensates thermal
effects, improving performance.

• Precise Input Compensation during operation is achieved
with temperature and pressure correction coefficients that
are characterized over the range of the transmitter and
stored in the sensor module EEPROM memory.

• EEPROM stores sensor information and correction
coefficients separately from MCU module, allowing for easy
repair, reconfiguration and replacement.

Basic Setups

The following settings can be easily configured from any host
that supports the HART® protocol:

• Operational Parameters

• 4-20 mA Points (Zero/Span)

• Engineering Units

• Damping Time: 0.25...60 sec

• Tag: 8 Alphanumeric Characters

• Descriptor: 16 Characters

• Message: 32 Characters

• Date: Day/Month/Year

Self-Diagnosis and others

• CPU & Analog Module Fault Detection

• Communication Error

• Fail-mode Handling

• LCD Indication

• Temperature Measurement of Sensor Module

Multi Planar Process Connection

When the pressure transmitter should be vertically installed irrespective
of the orientation of the process connection lines, modified flanges
(as shown above) are required in addition to the basic flanges. Multi­planar pressure transmitters have been made in an effort to solve
the problems occurring in these types of installation. The object of
this is to provide a pressure transmitter, capable of being vertically
installed, without separate adapters or various types of brackets.
This is regardless of the position of the process connection lines.

Calibration and Adjustment

• Lower/Upper Range (Zero/Span)

• Sensor Zero Trimming

• Zero Point Adjustment

• DAC Output Trimming

• Transfer Function

• Self-Compensation

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

Process Connection Via Diaphragm Seals

When connecting the differential pressure transmitter model PAD to
all different process connections, diverse diaphragm seal versions
are necessary. They can be connected to the differential pressure
transmitter by direct mounting or via a capillary tube. Depending on
the application, different combinations of diaphragm seals, capillary
tubes and fill fluids are available. To clarify those options, the special
connections via diaphragm seals should be specified separately for
the differential pressure transmitter.

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3

Heavy Duty Differential Pressure Transmitter Model PAD

Technical Details

Measuring Principle: Capacitance Sensor (PAD-D, -F, -G, -H)
Piezo-resistive (PAD-A)

Measuring Span: 0.3" W.C..6" W.C. to 60…6,000 PSIG
bar (Depending on Instrument Version)
Zero and Span Values can be set
anywhere within the Range Limits.
Span must be Greater than or Equal
to the Minimum Span.

Accuracy
Range 2: ±0.25 % of Span for

0.1 URL ≤ Span ≤ URL
±[0.24 + (0.008 x (URL/Span)) % of
Span for 0.05 URL ≤ Span ≤0.1 URL

Range 3: ±0.075 % of Span for

0.1 URL ≤ Span ≤ URL
±[0.25 + (0.005 x (URL/span))] % of
Span for 0.02 URL ≤ Span ≤0.1 URL

Range 4 to 0: ±0.075 % of Span for

0.1 URL ≤ Span ≤ URL
±[0.025+(0.005x(URL/Span))] % of
Span for 0.01 URL ≤ Span ≤0.1 URL

Stability: ± 0.125% URL for 36 Months
Static Press. Effect: ± 0.1% URL per 70 bar (Zero Error)

± 0.2% of Reading per 70 bar (Span Error)
Turndown Ratio: Ranges 4 ~ 0 = 100 : 1

Range 3 = 50 : 1
Range 2 = 20 : 1

Process Temp.: -40…248 °F
(Approval Codes may Affect Limits.
Max. Ambient Temperature at
LCD = 176 °F.)

Ambient Temp.: -22…176 °F
Ambient Temp.

Effect: ± (0.019% URL + 0.125% Span) /28 °C
Storage Temp.: -40…185 °F (Non-condensing)
Humidity Limit: 5 %...100 % RH
Power Supply Effect: ± 0.005% of span per Volt
Mounting Pos. Effect: Zero Shift up to 350 Pa, no span effect

Pressure Limits (with Silicone Oil)

(Valid for stand-alone instruments only without assembled
diaphragm seals.)

Model D and G: 0…1999.6 PSIG (for Range 2...8)
Model G: 0…5800 PSIG (for Range 9)

0...10875 PSIG (for Range 0)
Model H: 0…4495 PSIG (for Range 4...7)
Model A: 0…72.5 PSIG (for Range 4)
0…435 PSIG (for Range 5)
0…754 PSIG (for Range 6)

Burst Pressure
Model D, G and H: 9990.5 PSIG

11600 PSIG (for Model G, Range 0)
Model A: 145 PSIG (for Range 4)
580 PSIG (for Range 5)
1015 PSIG (for Range 6)

4

Wetted Materials
Isolating Diaphragms: 316L SS

Drain/Vent Valves: 316 SS
Flanges/Adapters: 316 SS

O-ring: FKM, PTFE as an Option

Non-Wetted Materials
Fill Fluid: Silicone Oil

Bolts: Stainless Steel
Housing: Aluminum or SS, Flameproof (Ex d) and

Waterproof (lP67)
Cover O-ring: NBR

Paint: Epoxy-polyester or Polyurethane
Mounting Bracket: For 2-inch Pipe, 304 SS,

with 304 SS U-bolt

Nameplate: 304 SS
Process

Connections: ¼" NPT with 54.0 mm Center

Distance for Standard Flanges,
½" NPT with Process Adapter
(Option)

Mount Position: Upright (Process Connection more
Flexible by using Multi-planar Flange)

Display: 5 Digit LCD
Power Supply: 12…45 VDC

17.5…45 VDC -HART® Communication
Maximum Load: 250 Ω at 17.5 VDC

550 Ω at 24 V
Max. Loop Resistance =
Loop Load: 0...1500 Ω - Operation

250...550 Ω - HART® Communication
Failure Mode: Fail High: Current ≥ 21.1 mA

Fail Low: Current ≤ 3.78 mA

Electrical
Connection: ½" NPT Conduit with M4 Screw

Terminals (G½ Option)
Output: • Two Wire 4…20 mA, Configurable

for Linear or Square Root Output, Digital
Process Value Superimposed on
4…20 mA Signal, Available to any Host
that Conforms to the HART® Protocol

• Frequency Output for Flowmeter
Model PAD-F with Pulse Width of 10,
50 or 100 ms (Selectable, Negative
Going Pulse)
Output Type: Open Collector, 30 V,
500 mA max.
Pulse Rate: 49 pulses/sec max.

Turn-On Time: 3 seconds
Protection: IP 67 for Standard (Code S)
Weight: 8.6 lb (Excluding Options) Standard

11.8 lb (SS Housing - Excl. Options)

ATEX Approval
(Option): II 2G Exd IIC T6 ... T5

II 1G or 2G Ex ia IIC T5 or
T4 Ga or Gb

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DC

(U - 12 VDC)

0.022 A

No responsibility taken for errors;

subject to change without prior notice.

Heavy Duty Differential Pressure Transmitter Model PAD

Order Details (Example: PAD-D EE 2 S 2 N S 0 0)

Model Version

..D.. = Differential Pressure Transmitter

(Static Pressure 2000 PSI)

..F..1) = Differential Pressure Transmitter with
Pulse Output and Totalizer for

PAD-

Flow Measurement

..H.. = Differential Pressure Transmitter for High
Line Pressure (Static Pressure 4495 PSI)

..G.. = Gauge Pressure Transmitter

..A.. = Absolute Pressure Transmitter

Material

Body/Vent Plug/

Diaphragm

..EE.. = 316 SS / 316 SS / 316L SS

Calibrated Span

(Measuring Range Limits for PAD-D,

-F, -G and -H in Separate Table)

Calibrated Span for
PAD-D, -F, -G, -H

..2..3) = 0.3"...6" W.C.
..3.. = 0.6"...30" W.C.
..4.. = 1.5"...150" W.C.
..5.. = 7.5"...750" W.C.
..6.. = 1...100 PSIG
..7.. = 3...300 PSIG
..8..3) = 10 ...1000 PSIG

3)4)

..9..
..0..

= 30...3000 PSIG

3)4)

= 60...6000 PSIG

Calibrated Span for PAD-A
..4.. = 10"...1000" W.C.
..5.. = 1.5...217 PSIA
..6.. = 3...362 PSIA

Order Details Continued

Fill Liquid Process Connection

..S.. = Silicone

1)

Specify flow rate engineering unit, ∆ p and flow rate
at URV (Upper Range Value), ∆ p and flow rate (generally '0')
at LRV (Lower Range Value)
pulse scale (choose only one value from

0.001, 0.01, 0.1, 1, 10, 100, 1 000, 10 000 m³/pulse) and
pulse width (choose only one value from
10 ms, 50 ms, 100 ms), while ordering so that max.
duty cycle is 49 pulses/sec

..2..6) = ¼" NPT

Female

Electrical

Connection

..N.. = ½" NPT

Epoxy­ Polyester
Painted
Aluminum

..G.. =G ½ Epoxy­ Polyester
Painted
Aluminum

Approvals Options

..S0.. = Standard

(Waterproof
IP67)

..F0.. = ATEX,
Flameproof, Ex d

..E0.. = ATEX,
Intrinsically Safe, Ex i

3)

Not for PAD-H

4)

Not for PAD-D and PAD-F

5)

Diaphragm seal model and application data to be specified in clear text.
The online application guide on the PAD product page of the website must be
completed for any PAD ordered with a DRM. For summary of
diaphragm seal models and possible ranges, see page 11 onwards. For
dimensional details see DRM data sheet.

6)

1/2" NPT connection via an adapter is available, see page 6

..0 = without
..C = Engineering Unit (must be

chosen when using the
differential transmitter as a
flowmeter)

..D = PTFE O-ring (Wetted Part)
..E = Oil Free Finish
..F = Side Vent / Drain Bottom
..G = Side Vent / Drain Top
..H = Multi-Planar

Process Connection

..M = Housing in Stainless Steel
..N5) = Mounting of PAD onto

Diaphragm Seal

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

www.koboldusa.com

5

Heavy Duty Differential Pressure Transmitter Model PAD

Order Details: Oval Flange Adapter

Description Order Number

1/2" NPT Oval Flange Adapter

ZUB-PAD-OVF

Technical Details
Material: 316 Stainless Steel
Seal: PTFE
Bolts: 2 x Mounting Screws 7/16"-20 UNF
Connection: ½" NPT Female

Dimensions

1.63"

Order Details: Mounting Brackets

Description Order Number

Angle Type Bracket for PAD/PAS
Vertical Pipe Mounting for PAS
Vertical Pipe Mounting for PAD
Incl. U-Clamp for 2“ Pipe Mounting Bracket and 2 x Mounting Nuts/Washers
Incl. 4 x Mounting Screws for PAS
Incl. 4 x Mounting Screws for PAD

Flat Type Bracket for PAD/PAS
Horizontal Pipe Mounting for PAS
Vertical Pipe Mounting for PAD
Incl. U-Clamp for 2“ Pipe Mounting Bracket and Mounting Nuts/Washers
Incl. 4 x Mounting Bolts and Washers for PAS
Incl. 4 x Mounting Bolts for PAD

Order Details: Manifold Valves

Description Order Number

3-way Manifold Valve, Remote Mount, Machined
5-way Manifold Valve, Remote Mount, Machined

2-way Manifold Valve, Direct Mount, Machined

2-way Compact Manifold Valve, Direct Mount, Machined
3-way Compact Manifold Valve, Direct Mount, Machined
5-way Compact Manifold Valve, Direct Mount, Machined

3-way Manifold Valve, Direct Mount, Forged

0.98"

ZUB-PAD/PAS-K

ZUB-PAD/PAS-L

ZUB-PAD-3WMR
ZUB-PAD-5WMR

ZUB-PAD-2WMD

V-2003CDADABAA

V-3151CHHHIBAA
V-5050CDAHIBAA

V-3454CHHHHBAA

6

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No responsibility taken for errors;

subject to change without prior notice.

Heavy Duty Differential Pressure Transmitter Model PAD

Measuring Range Limits for PAD-D, -F, -G and -H

Range Code Calibrated Span

PAD-D, -F PAD-G PAD-H

Lower Range Limit (LRL)

Upper Range Limit (URL)

2 0.3...6" W.C. -6" W.C. -6" W.C. - 6" W.C.

3 0.6...30" W.C. -30" W.C. -30" W.C. - 30" W.C.

4 1.5...150" W.C. -150" W.C. -150" W.C. -150" W.C. 150" W.C.

5 7.5...750" W.C. -750" W.C. -14.5 PSIG -750" W.C. 750" W.C.

6 1...100 PSIG -100 PSIG -14.5 PSIG -100 PSIG 100 PSIG

7 3...300 PSIG -300 PSIG -14.5 PSIG -300 PSIG 300 PSIG

8 10...1000 PSIG -1000 PSIG -14.5 PSIG - 1000 PSIG

9 30...3000 PSIG - -14.5 PSIG - 3000 PSIG

0 60...6000 PSIG - -14.5 PSIG - 6000 PSIG

* Special measuring span, with adequate lower and upper range limits, on request.

Range Code Unit Conversion

Range Code bar kg/cm² KPa psi in H2O at 39 °F

2 0.015 0.015 1.5 0.217 6 152 0.422

3 0.075 0.076 7.5 1.087 30 765 2.215

4 0.373 0.38 37.3 5.410 149 3804 11.014

5 1.865 1.902 186.5 27 749 19018 55.072

6 6.900 7.036 690 100 2773 70361 203.750

7 20.681 21.088 2068 300 8310 210878 610.660

8 68.950 70.309 6895 1000 27708 703097 2036.025

9 206.800 210.876 20680 3000 83105 2108781 6106.597

0 413.700 421.856 41370 6000 166085 4218566 12216.550

mm H2O at

39 °F

in Hg at 32 °F

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

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7