WIKA CPT-2 series Operating Instructions Manual
Operating Instructions
Process pressure transmitter CPT-2x
Process pressure transmitter CPT-2x
Slave for electronic dierential pressure
With SIL qualication
Ceramic sensor
2
Contents
WIKA Operating Instructions - Process pressure transmitter CPT-2x
Contents
1 About this document ............................................................................................................... 4
1.1 Function ........................................................................................................................... 4
1.2 Target group ..................................................................................................................... 4
1.3 Symbols used................................................................................................................... 4
2 For your safety ......................................................................................................................... 5
2.1 Authorised personnel ....................................................................................................... 5
2.2 Appropriate use ................................................................................................................ 5
2.3 Warning about incorrect use ............................................................................................. 5
2.4 General safety instructions ............................................................................................... 5
2.5 EU conformity ................................................................................................................... 6
2.6 SIL qualication according to IEC 61508 .......................................................................... 6
2.7 Permissible process pressure .......................................................................................... 6
2.8 Installation and operation in the USA and Canada ........................................................... 6
3 Product description ................................................................................................................. 7
3.1 Conguration .................................................................................................................... 7
3.2 Principle of operation........................................................................................................ 8
3.3 Supplementary cleaning procedures .............................................................................. 13
3.4 Packaging, transport and storage ................................................................................... 14
4 Mounting ................................................................................................................................. 15
4.1 General instructions ....................................................................................................... 15
4.2 Ventilation and pressure compensation .......................................................................... 16
4.3 Combination Master - Slave ........................................................................................... 18
4.4 Level measurement ........................................................................................................ 20
4.5 Dierential pressure measurement ................................................................................ 21
4.6 Interface measurement .................................................................................................. 21
4.7 Density measurement .................................................................................................... 22
4.8 Density-compensated level measurement ..................................................................... 23
4.9 External housing ............................................................................................................ 25
5 Connecting to power supply ................................................................................................. 26
5.1 Preparing the connection ............................................................................................... 26
5.2 Connecting ..................................................................................................................... 26
5.3 Single chamber housing ................................................................................................. 28
5.4 External housing with version IP 68 (25 bar)................................................................... 28
5.5 Connection example ...................................................................................................... 30
6 Functional safety (SIL) .......................................................................................................... 31
6.1 Objective ........................................................................................................................ 31
6.2 SIL qualication .............................................................................................................. 31
6.3 Application area ............................................................................................................. 31
6.4 Safety concept of the parameterization .......................................................................... 32
7 Set up with the display and adjustment module ................................................................ 34
7.1 Parameter adjustment .................................................................................................... 34
8 Diagnosis, asset management and service ........................................................................ 47
8.1 Maintenance .................................................................................................................. 47
8.2 Cleaning - hygienic connection with compression nut .................................................... 47
8.3 Rectify faults ................................................................................................................... 48
3
Contents
WIKA Operating Instructions - Process pressure transmitter CPT-2x
8.4 Exchange process module on version IP 68 (25 bar) ..................................................... 48
8.5 Instrument repair ............................................................................................................ 49
9 Dismount................................................................................................................................. 51
9.1 Dismounting steps.......................................................................................................... 51
9.2 Disposal ......................................................................................................................... 51
10 Supplement ............................................................................................................................ 52
10.1 Technical data ................................................................................................................ 52
10.2 Calculation of the total deviation ..................................................................................... 62
10.3 Practical example ........................................................................................................... 63
10.4 Dimensions .................................................................................................................... 66
10.5 Trademark ...................................................................................................................... 74
Safety instructions for Ex areas
Take note of the Ex specic safety instructions for Ex applications.
These instructions are attached as documents to each instrument
with Ex approval and are part of the operating instructions manual.
Editing status: 2017-11-23
4
1 About this document
WIKA Operating Instructions - Process pressure transmitter CPT-2x
1 About this document
1.1 Function
This operating instructions manual provides all the information you
need for mounting, connection and setup as well as important instructions for maintenance, fault rectication, the exchange of parts and
the safety of the user. Please read this information before putting the
instrument into operation and keep this manual accessible in the im-
mediate vicinity of the device.
1.2 Target group
This operating instructions manual is directed to trained personnel.
The contents of this manual must be made available to the qualied
personnel and implemented.
1.3 Symbols used
Information, tip, note
This symbol indicates helpful additional information.
Caution: If this warning is ignored, faults or malfunctions can result.
Warning: If this warning is ignored, injury to persons and/or serious
damage to the instrument can result.
Danger: If this warning is ignored, serious injury to persons and/or
destruction of the instrument can result.
Ex applications
This symbol indicates special instructions for Ex applications.
•
List
The dot set in front indicates a list with no implied sequence.
→
Action
This arrow indicates a single action.
1 Sequence of actions
Numbers set in front indicate successive steps in a procedure.
Battery disposal
This symbol indicates special information about the disposal of batteries and accumulators.
5
2 For your safety
WIKA Operating Instructions - Process pressure transmitter CPT-2x
2 For your safety
2.1 Authorised personnel
All operations described in this operating instructions manual must
be carried out only by trained specialist personnel authorised by the
plant operator.
During work on and with the device the required personal protective
equipment must always be worn.
2.2 Appropriate use
CPT-2x is a slave sensor for electronic dierential pressure measure-
ment.
You can nd detailed information about the area of application in
chapter "Product description".
Operational reliability is ensured only if the instrument is properly
used according to the specications in the operating instructions
manual as well as possible supplementary instructions.
2.3 Warning about incorrect use
Inappropriate or incorrect use of this product can give rise to application-specic hazards, e.g. vessel overll through incorrect mounting
or adjustment. Damage to property and persons or environmental
contamination can result. Also, the protective characteristics of the
instrument can be impaired.
2.4 General safety instructions
This is a state-of-the-art instrument complying with all prevailing
regulations and directives. The instrument must only be operated in a
technically awless and reliable condition. The operator is responsible for the trouble-free operation of the instrument. When measuring
aggressive or corrosive media that can cause a dangerous situation
if the instrument malfunctions, the operator has to implement suitable
measures to make sure the instrument is functioning properly.
During the entire duration of use, the user is obliged to determine the
compliance of the necessary occupational safety measures with the
current valid rules and regulations and also take note of new regulations.
The safety instructions in this operating instructions manual, the national installation standards as well as the valid safety regulations and
accident prevention rules must be observed by the user.
For safety and warranty reasons, any invasive work on the device
beyond that described in the operating instructions manual may be
carried out only by personnel authorised by the manufacturer. Arbitrary conversions or modications are explicitly forbidden. For safety
reasons, only the accessory specied by the manufacturer must be
used.
6
2 For your safety
WIKA Operating Instructions - Process pressure transmitter CPT-2x
To avoid any danger, the safety approval markings and safety tips on
the device must also be observed and their meaning looked up in this
operating instructions manual.
2.5 EU conformity
The device fulls the legal requirements of the applicable EU directives. By axing the CE marking, we conrm the conformity of the
instrument with these directives.
2.6 SILqualicationaccordingtoIEC61508
The Safety Integrity Level (SIL) of an electronic system is used to assess the reliability of integrated safety functions.
For detailed specication of the safety requirements, multiple SIL
levels are specied according to safety standard IEC 61508. You can
nd detailed information in chapter "Functional safety (SIL)" of the
operating instructions.
The instrument meets the specications of IEC 61508: 2010 (Edition 2). It is qualied for single-channel operation up to SIL2. The
instrument can be used homogeneously redundant up to SIL3 in
multi-channel architecture with HFT 1.
2.7 Permissible process pressure
For safety reasons, the instrument must only be operated within the
permissible process conditions. You can nd detailed information on
the process conditions in chapter "Technical data" as well as on the
type label.
The permissible process pressure range is specied on the type label
with "Process pressure", see chapter "Conguration". This applies
even if a measuring cell with a measuring range (order-related) higher
than the permissible pressure range of the process tting is installed.
A temperature derating, e.g. with anges, can limit the permissible
process pressure range.
2.8 Installation and operation in the USA and
Canada
This information is only valid for USA and Canada. Hence the following text is only available in the English language.
Installations in the US shall comply with the relevant requirements of
the National Electrical Code (ANSI/NFPA 70).
Installations in Canada shall comply with the relevant requirements of
the Canadian Electrical Code
7
3 Product description
WIKA Operating Instructions - Process pressure transmitter CPT-2x
3 Product description
3.1 Conguration
The type label contains the most important data for identication and
use of the instrument:
4
1
5
10
12
11
13
14
3
2
6
7
8
9
Fig. 1: Layout of the type label (example)
1 Instrument type
2 Field for approvals
3 Power supply and signal output, electronics
4 Protection rating
5 Measuring range
6 Permissible process conditions
7 Material wetted parts
8 Product code
9 Order number
10 Serial number of the instrument
11 Symbol of the device protection class
12 ID numbers, instrument documentation
13 Reminder to observe the instrument documentation
14 SIL identication
This operating instructions manual applies to the following instrument
versions:
•
Hardware from 1.0.0
•
Software version from 1.0.0
Note:
You can nd the hardware and software version of the instrument as
follows:
•
On the type plate of the electronics module
•
In the adjustment menu under "Info"
The scope of delivery encompasses:
•
Instrument CPT-2x - Slave sensor
•
Ready-made connection cable, unassembled cable gland
•
Documentation
– Quick setup guide CPT-2x
– Safety Manual (SIL)
Type label
Scope of this operating
instructions manual
Scope of delivery
8
3 Product description
WIKA Operating Instructions - Process pressure transmitter CPT-2x
– Documentation instrument parameters (default values)
– Documentation order-relating instrument parameters (deviation
from default values)
– Test certicate for pressure transmitters
– Instructions for optional instrument features
– Ex-specic "Safety instructions" (with Ex versions)
– If necessary, further certicates
Information:
Optional instrument features are also described in this operating
instructions manual. The respective scope of delivery results from the
order specication.
3.2 Principle of operation
The CPT-2x slave sensor is combined with a sensor from the instrument series for electronic dierential pressure measurement.
1
2
Fig. 2: Example, electronic dierential pressure for level measurement in pressurized vessel
1 CPT-2x
2 CPT-2x, slave sensor
The sensors are connected via a screened four-wire cable. The
measured value from the slave sensor is read in and factored into the
calculations. Power supply and parameter adjustment are carried out
through the master sensor.
Electronicdierential
pressure
9
3 Product description
WIKA Operating Instructions - Process pressure transmitter CPT-2x
Information:
The version "Relative pressure climate-compensated" is not suitable.
You can nd further information in chapter "Combination Master -
Slave " of this operating instructions.
To reach the Safety Integrity Level (SIL) for the electronic dierential
pressure, both instruments must be SIL-qualied.
The electronic dierential pressure measurement is suitable for the
measurement of the following process variables:
•
Level
•
Flow
•
Dierential pressure
•
Density
•
Interface
•
Level, density-compensated
CPT-2x is suitable for applications in virtually all industries. It is used
for the measurement of the following pressure types.
•
Gauge pressure
•
Absolute pressure
•
Vacuum
Measured products are gases, vapours and liquids.
Depending on the process tting and measurement setup, measured
products can be also viscous or contain abrasive substances.
Sensor element is the measuring cell with robust ceramic diaphragm.
The process pressure deects the ceramic diaphragm and causes a
capacitance change in the measuring cell. This capacitance change
is converted into an electrical signal and outputted as measured value
via the output signal.
16 µm
1
2
3
Fig. 3: Conguration of the ceramic measuring cell
1 Process diaphragm
2 Glass joint
3 Base element
The measuring cell is available in two sizes:
Measured variables
Application area
Measured products
Measuring system pressure
10
3 Product description
WIKA Operating Instructions - Process pressure transmitter CPT-2x
•
ø 28 mm with large process and ange connections as well as with
measuring ranges 25 mbar and 100 bar
•
ø 17.5 mm with small process ttings
A temperature sensor in the ceramic diaphragm of the ø 28 mm or on
the ceramic base of the ø 17.5 mm measuring cell detects the actual
process temperature. The temperature value is outputted via the
master sensor.
Extreme process temperature jumps are also immediately detected
by the ø 28 mm measuring cell. The values are compared with that of
an additional temperature measurement on the ceramic base body.
Within only a few measuring cycles the intelligent sensor electronics
compensates unavoidable measurement deviations due to temperature shocks. Such shocks cause (depending on the set damping) only
slight, brief changes to the output signal.
The measuring cell design depends on the selected pressure type.
Relative pressure: the measuring cell is open to the atmosphere.
The ambient pressure is detected in the measuring cell and compensated. It thus has no inuence on the measured value.
Absolute pressure: the measuring cell is evacuated and encapsulated. The ambient pressure is not compensated and does hence
inuence the measured value.
The following presentations show examples for the installation of the
ceramic measuring cell into the process tting and the dierent seal
concepts.
The recessed installation is particularly suitable for applications with
gases, vapours and clear liquids. The measuring cell seal is positioned laterally as well as in addition in front.
Measuring system temper
atur
e
Pressure types
Seal concepts
Recessed installation
11
3 Product description
WIKA Operating Instructions - Process pressure transmitter CPT-2x
1
2
5
6
3
4
Fig. 4: Recessed installation of the measuring cell (example: manometer connection G½)
1 Measuring cell
2 Seal for the measuring cell
3 Additional, front seal for measuring cell
4 Diaphragm
5 Process tting
6 Seal for the process tting
The front-ush installation is particularly suitable for applications with
viscous and abrasive media and in case of buildup. The measuring
cell seal is positioned laterally.
2
3
4
1
5
Fig. 5: Front-ush installation of the measuring cell (example: thread G1½)
1 Seal for the process tting
2 Measuring cell
3 Seal for the measuring cell
4 Process tting
5 Diaphragm
The completely front-ush mounting is particularly suitable for ap-
plications in the paper industry. The diaphragm is in the pulp ow, is
hence cleaned and protected against buildup.
Front-ushmountingwith
single seal
Completelyfront-ush
mounting with single seal
12
3 Product description
WIKA Operating Instructions - Process pressure transmitter CPT-2x
1
2
3
4
5
Fig. 6: Front-ush installation of the measuring cell (example: M30 x 1.5)
1 Measuring cell
2 Seal for the measuring cell
3 Seal for the process tting
4 Process tting
5 Diaphragm
The front-ush installation is particularly suitable for applications with
viscous media. The additional, front sealing protects the glass joint
of the measuring cell against chemical attack and the measuring cell
electronics against diusion of aggressive gases from the process.
1
2
3
4
5
Fig. 7: Front-ush installation of the measuring cell with double seal (example:
ange connection with extension)
1 Measuring cell
2 Seal for the measuring cell
3 Process tting
4 Additional, front seal for measuring cell
5 Diaphragm
The front-ush, hygienic installation of the measuring cell is particularly suitable for food applications. The sealings are installed gap-free.
The form seal of the measuring cell protects also the glass joint.
Front-ushmountingwith
double seal
Installation in hygienic
tting
13
3 Product description
WIKA Operating Instructions - Process pressure transmitter CPT-2x
1
2
3
4
5
Fig. 8: Hygienic installation of the measuring cell (example: hygienic tting with
compression nut)
1 Measuring cell
2 Form seal for the measuring cell
3 Gap-free seal for process tting
4 Process tting
5 Diaphragm
The front-ush, hygienic installation of the measuring cell acc. to 3A
is particularly suitable for food applications. The sealings are installed
gap-free. The additional front sealing for the measuring cell protects
also the glass joint. A hole in the process tting is used for leakage
detection.
1
6
2
3
4
5
Fig. 9: Hygienic installation of the measuring cell acc. to 3-A (example: Clamp
connection)
1 Measuring cell
2 Seal for the measuring cell
3 Process tting
4 Additional, front seal for measuring cell
5 Diaphragm
5 Hole for leakage detection
3.3 Supplementary cleaning procedures
The CPT-2x is also available in the version "Oil, grease and silicone-
free". These instruments have passed through a special cleaning
procedure to remove oil, grease and paint-wetting impairment substances (PWIS).
The cleaning is carried out on all wetted parts as well as on surfaces
accessible from outside. To keep the purity level, the instruments are
immediately packed in plastic foil after the cleaning process. The
purity level remains as long as the instrument is kept in the closed
original packaging.
Installation in hygienic
ttingacc.to3-A
14
3 Product description
WIKA Operating Instructions - Process pressure transmitter CPT-2x
Caution:
The CPT-2x in this version may not be used in oxygen applications.
For this purpose, instruments are available in the special version "Oil
and grease-free for oxygen applications".
3.4 Packaging, transport and storage
Your instrument was protected by packaging during transport. Its
capacity to handle normal loads during transport is assured by a test
based on ISO 4180.
The packaging of standard instruments consists of environmentfriendly, recyclable cardboard. For special versions, PE foam or PE
foil is also used. Dispose of the packaging material via specialised
recycling companies.
Transport must be carried out in due consideration of the notes on the
transport packaging. Nonobservance of these instructions can cause
damage to the device.
The delivery must be checked for completeness and possible transit
damage immediately at receipt. Ascertained transit damage or concealed defects must be appropriately dealt with.
Up to the time of installation, the packages must be left closed and
stored according to the orientation and storage markings on the
outside.
Unless otherwise indicated, the packages must be stored only under
the following conditions:
•
Not in the open
•
Dry and dust free
•
Not exposed to corrosive media
•
Protected against solar radiation
•
Avoiding mechanical shock and vibration
•
Storage and transport temperature see chapter "Supplement Technical data - Ambient conditions"
•
Relative humidity 20 … 85 %
With an instrument weight of more than 18 kg (39.68 lbs) suitable and
approved equipment must be used for lifting and carrying.
Packaging
Transport
Transport inspection
Storage
Storage and transport
temperature
Lifting and carrying
15
4 Mounting
WIKA Operating Instructions - Process pressure transmitter CPT-2x
4 Mounting
4.1 General instructions
Make sure before mounting that all parts of the instrument exposed to
the process are suitable for the existing process conditions.
These are mainly:
•
Active measuring component
•
Process tting
•
Process seal
Process conditions in particular are:
•
Process pressure
•
Process temperature
•
Chemical properties of the medium
•
Abrasion and mechanical inuences
You can nd detailed information on the process conditions in chapter
"Technical data" as well as on the type label.
The instrument is suitable for standard and extended ambient condi-
tions acc. to DIN/EN/IEC/ANSI/ISA/UL/CSA 61010-1.
Protect your instrument against moisture ingress through the following
measures:
•
Use a suitable connection cable (see chapter "Connecting to
power supply")
•
Tighten the cable gland
•
When mounting horizontally, turn the housing so that the cable
gland points downward
•
Loop the connection cable downward in front of the cable gland
This applies mainly to outdoor installations, in areas where high
humidity is expected (e.g. through cleaning processes) and on cooled
or heated vessels.
To maintain the housing protection, make sure that the housing lid is
closed during operation and locked, if necessary.
Make sure that the degree of contamination specied in chapter
"Technical data" meets the existing ambient conditions.
On instruments with threaded process tting, the hexagon must be
tightened with a suitable wrench. For the proper wrench size see
chapter "Dimensions".
Warning:
The housing must not be used to screw the instrument in! Applying
tightening force can damage internal parts of the housing.
If there is strong vibration at the mounting location, the instrument
version with external housing should be used. See chapter "External
housing".
Suitability for the process
conditions
Suitability f
or the ambient
conditions
Pr
otection against mois-
ture
Screwing in
Vibrations
16
4 Mounting
WIKA Operating Instructions - Process pressure transmitter CPT-2x
Higher process temperatures often mean also higher ambient
temperatures. Make sure that the upper temperature limits stated in
chapter "Technical data" for the environment of the electronics hous-
ing and connection cable are not exceeded.
1
2
Fig. 10: Temperature ranges
1 Process temperature
2 Ambient temperature
4.2 Ventilation and pressure compensation
Ventilation and pressure compensation are carried out with CPT-2x
via a lter element. It is air permeable and moisture-blocking.
Caution:
The lter element causes a time-delayed pressure compensation.
When quickly opening/closing the housing cover, the measured value
can change for approx. 5 s by up to 15 mbar.
For eective ventilation, the lter element must always be free of
buildup.
Caution:
Do not use a high-pressure cleaner. The lter element could be damaged, which would allow moisture into the housing.
The following paragraphs describe how the lter element is arranged
in the dierent instrument versions.
The lter element is mounted into the electronics housing. It has the
following functions:
•
Ventilation of the electronics housing
•
Atmospheric pressure compensation (with relative pressure measuring ranges)
→
Turn the housing so that the lter element points downward after
the instrument is installed. This provides better protection against
buildup.
Temperature limits
Filter elements
Instruments in non-Ex
and Ex-ia version
17
4 Mounting
WIKA Operating Instructions - Process pressure transmitter CPT-2x
1 2 3
4 4 4
Fig. 11: Position of the lter element - non-Ex, Ex-ia version
1 Plastic, stainless steel housing (precision casting)
2 Aluminium housing
3 Stainless steel housing (electropolished)
4 Filter element
With the following instruments a blind plug is installed instead of the
lter element:
•
Instruments in protection IP 66/IP 68 (1 bar) - ventilation via capillaries in non-detachable cable
•
Instruments with absolute pressure
The lter element is integrated in the process assembly. It is located in
a rotatable metal ring and has the following function:
•
Atmospheric pressure compensation (with relative pressure measuring ranges)
→
Turn the metal ring in such a way that the lter element points
downward after installation of the instrument. This provides better
protection against buildup.
1
2
Fig. 12: Position of the lter element - Ex-d version
1 Rotatable metal ring
2 Filter element
Instruments with absolute pressure have a blind plug mounted
instead of the lter element.
The lter element is mounted into the electronics housing. It has the
following functions:
•
Ventilation of the electronics housing
→
Turn the housing so that the lter element points downward after
the instrument is installed. This provides better protection against
buildup.
Instruments in Ex-d version
Instruments with Second
Line of Def
ense
18
4 Mounting
WIKA Operating Instructions - Process pressure transmitter CPT-2x
The process assembly of instruments with Second Line of Defense
(gastight leadthrough) is completely encapsulated. An absolute pressure measuring cell is used so that no ventilation is required.
1
2
Fig. 13: Position of the lter element - gastight leadthrough
1 Filter element
The lter element is mounted into the electronics housing. It has the
following functions:
•
Ventilation of the electronics housing
•
Atmospheric pressure compensation (with relative pressure measuring ranges)
→
Turn the housing so that the lter element points downward after
the instrument is installed. This provides better protection against
buildup.
1
Fig. 14: Position of the lter element - IP 69K version
1 Filter element
Instruments with absolute pressure have a blind plug mounted
instead of the lter element.
4.3 Combination Master - Slave
In principle, any sensor combination within the instrument series is
allowed. The following requirements must be fullled:
•
Conguration, Master sensor suitable for electronic dierential
pressure
•
Pressure type is identical for both sensors, i.e. relative pressure/
relative pressure or absolute pressure/absolute pressure
•
Master sensor measures the higher pressure
•
Measurement setup as shown in the following chapters
Instruments in IP 69K
version
19
4 Mounting
WIKA Operating Instructions - Process pressure transmitter CPT-2x
The measuring range of each sensor is selected such that it ts the
measuring loop. For this, the max. recommended turn down must be
noted. See chapter "Technical data". It is absolutely necessary the the
measuring ranges of Master and Slave correspond.
Measurement result = Measured value of Master (total pressure) - measured value of Slave (static pressure)
Depending on the application, individual combinations can result, see
following examples:
Data
Application: Level measurement
Medium: Water
Vessel height: 12 m, hydrostatic pressure = 12 m x 1000 kg/m3 x
9.81 m/s2 = 117.7 kPa = 1.18 bar
Superimposed pressure: 1 bar
Total pressure: 1.18 bar + 1 bar = 2.18 bar
Instrument selection
Nominal measuring range Master: 2.5 bar
Nominal measuring range Slave: 1 bar
Turn Down: 2.5 bar/1.18 bar = 2.1 : 1
Data
Application: Level measurement
Medium: Water
Vessel height: 500 mm, hydrostatic pressure = 0.50 m x 1000 kg/m3 x
9.81 m/s2 = 4.9 kPa = 0.049 bar
Superimposed pressure: 350 mbar = 0.35 bar
Total pressure: 0.049 bar + 0.35 bar = 0.399 bar
Instrument selection
Nominal measuring range Master: 0.4 bar
Nominal measuring range Slave: 0.4 bar
Turn Down: 0.4 bar /0.049 bar = 8.2 : 1
Data
Application: Dierential pressure measurement
Medium: Gas
Static pressure: 0.8 bar
Dierential pressure on orice: 50 mbar = 0.050 bar
Total pressure: 0.8 bar + 0.05 bar = 0.85 bar
Instrument selection
Nominal measuring range Master: 1 bar
Nominal measuring range Slave: 1 bar
Turn Down: 1 bar/0.050 bar = 20 : 1
Example - large vessel
Example - small vessel
Example-oricein
pipeline
20
4 Mounting
WIKA Operating Instructions - Process pressure transmitter CPT-2x
The measuring result (level, pressure dierence) as well as measured
value Slave (static or superimposed pressure) are outputted by the
sensor. Depending on the instrument version, output as 4 … 20 mA
signal or digitally via HART, Probus PA or Foundation Fieldbus.
To reach the Safety Integrity Level (SIL) for the electronic dierential
pressure, both instruments must be SIL-qualied.
4.4 Level measurement
The master/slave combination is suitable for level measurement in a
pressurized vessel
Keep the following in mind when setting up the measuring system:
•
Mount the master sensor below the min. level
•
Do not mount the master sensor close to the lling stream or
emptying area
•
Mount the master sensor so that it is protected against pressure
shocks from the stirrer
•
Mount the slave sensor above the max. level
2
Fig. 15: Measurement setup, level measurement in pressurized vessel
1 CPT-2x
2 CPT-2x, slave sensor
Output measured values
Measurement setup
21
4 Mounting
WIKA Operating Instructions - Process pressure transmitter CPT-2x
4.5 Dierentialpressuremeasurement
The master/slave combination is suitable for dierential pressure
measurement
Take note of the following instructions for the measurement setup, for
example in gases:
•
Mount the instruments above the measuring point
Possible condensation can then drain o into the process line.
1
2
Fig. 16: Measurement setup for dierential pressure measurement of gases in
pipelines
1 CPT-2x
2 CPT-2x, slave sensor
4.6 Interface measurement
The master/slave combination is suitable for interface measurement
Requirements for a functioning measurement are:
•
Vessel with changing level
•
Products with steady density
•
Interface always between the measurement points
•
Total level always above the upper measurement point
The mounting distance h of the two sensors should be at least 10 %,
better 20 %, of the nal value of the sensor measuring range. A bigger
distance increases the accuracy of the interface measurement.
Measurement setup
Measurement setup
22
4 Mounting
WIKA Operating Instructions - Process pressure transmitter CPT-2x
h
1,0
0,8
1
2
Fig. 17: Measurement setup with interface measurement, h = distance between
the two measuring points
1 CPT-2x
2 CPT-2x, slave sensor
The interface measurement is possible in open as well as in closed
vessels.
4.7 Density measurement
The master/slave combination is suitable for density measurement.
Requirements for a functioning measurement are:
•
Vessel with changing level
•
Distance between the measurement points as large as possible
•
Level always above the upper measuring point
Measurement setup
23
4 Mounting
WIKA Operating Instructions - Process pressure transmitter CPT-2x
h
1
2
Fig. 18: Measurement setup for density measurement, h = distance between the
two measuring points
1 CPT-2x
2 CPT-2x, slave sensor
The mounting distance h of the two sensors should be at least 10 %,
better 20 %, of the nal value of the sensor measuring range. A bigger
distance increases the accuracy of the density measurement.
Slight density changes cause only slight changes of the measured
dierential pressure. The measuring range must hence be selected
accordingly.
The density measurement is possible in open as well as in closed
vessels.
4.8 Density-compensated level measurement
The master/slave combination is suitable for density-compensated
level measurement
Keep the following in mind when setting up the measuring system:
•
Mount the master sensor below the min. level
•
Mount the slave sensor above the master sensor
•
Mount both sensors away from the lling stream and emptying and
protected against pressure shocks from the stirrer
Measurement setup
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