Electronic pressure measurement

Process transmitters

Versatile in application
Process transmitters are suitable for many industrial
measuring requirements in the widest variety of applications.

They monitor pumps, detect the level in vessels orcalculate quantities for flow measurement in pipelines.

The measured value can be read on-site as well as beingtransmitted to a process control system, a controller or aterminal.
The data transfer is achieved using an analogue 4 ... 20 mA
signal or via a bus protocol. With the HART®, PROFIBUS®
PA or FOUNDATION™ Fieldbus bus systems, there is thepossibility to transmit further information from the process
and/or measuring instrument, in addition to the primary
current signals, such as the operating hours or the sensor
temperature.

Furthermore, specific commands can be sent to the measuring instrument to change the parameters in the device.
Thus, the process can be adapted optimally without service
personnel having to attend on-site.
The communication between instruments using the fieldbus
protocols enables rapid transmission of data. Test reports
give information at any time about the status of the built-incomponents.

High flexibility
The transmitters can be fitted in a wide number of ways.
The ability for the position of the display heads to be adjusted
in relation to the process connection and the possibility of'snapping' the display into one of four directions makes its
mounting easier and guarantees the readability will always
be good. The large number of process connections and thepossibility of choosing between metal and ceramic measuring cells enables use in all industries.

2Applications■ Process engineering■ Machine building and plant construction■ Pharmaceutical industry■ Food and beverage industry

Process transmittersfrom WIKA
Special features

Primary and secondary circuits■ High measurement accuracy

Electronic differential pressure measurement with two
process transmitters■ Freely scalable measuring ranges■ Wetted parts from stainless steel or special materials■ Different Ex approvals■ Wide range of Ex approvals■ 4 ... 20 mA, 4 ... 20 mA HART® or bus signals■ Special materials or surface coatings possible

The internal digital signal processing, combined withproven sensors, guarantees high accuracy and the best
long-term stability.

Level monitoring by measuring differential pressure hasreached a new dimension: a system with two processtransmitters in a primary and secondary circuits. Compared
to conventional measurement solutions, this set-up has theadvantage of easier installation, a reduced temperature error
and higher accuracy.
In closed vessels where diaphragm seal assemblies incombination with differential pressure transmitters are used,
undesired effects on the measuring result often occur due totemperature changes in the process or in the environment.
The reason for this usually lies in the distance between theconnections and the measuring instrument. In conventional
differential pressure measurement, this distance is bridgedwith the aid of pressure capillaries. Although the vessel
content remains the same, changes in the measuring result
occur due to changed ambient temperatures.
With a master-slave pressure measurement, this influence iscompletely eliminated, since the existing distances between
the connection points are bridged by an electric signal cable,
so that temperature fluctuations do not have any effect on themeasuring result.

Level measurement for special requirements
Measurement in vessels is one of the most varied tasks insensor technology. For the measurement of filling height,
level, concentration of specific substances, density, layer
separation or volume, there are a whole range of different
measuring methods and sensors available.
Instruments within vessels or instruments mounted on thevessel cover are not suitable, for example, with aggressiveor strongly foaming media. Process transmitters lendthemselves to these measurements.

DPT-20 with two 990.27 flangetype diaphragm seals assembled via capillaries

Pharmaceuticalwater treatment

3

UPT-20 in electropolishedstainless steel casewith display andprocess connection G 1
Hygienic design

UPT-20 in an electricallyconductive plastic casewith display and G ½
process connection

Wide range of applications

Excellent readability

This measuring instrument is as suited to machine building
and plant construction as it is for the traditional areas forprocess transmitters. The UPT also finds its place in chemicalplants, especially in the Ex ia version (intrinsically safedesign).
With flush process connections and polished surfaces,
the requirements of the hygienic, pharmaceutical and foodindustries are also fulfilled. The instrument is available withanalogue output signal or with HART® protocol to the latest
HART® v7 revision.

The case of the UPT is rotatable around the connection sothat the ideal orientation towards the viewer can be made,even after mounting to the process. The electrical installationis possible on-site without the aid of tools. The instrument
has a high-contrast, clear and particularly large display.
With a 58 mm diameter, it is the largest on the market.
The digits of the main display, with a character height of
14 mm, can be read easily from a distance. With a tilt angle
for the display of 45°, reading from both the front and fromabove are equally possible without needing any modification
to the display.

4Universal process transmitters
Model UPT-20, with pressure port
Model UPT-21, with flush diaphragmSpecifications
Measuring ranges:
Absolute pressure 0 … 0.4 bar to 0 … 40 bar
Gauge pressure 0 … 0.4 bar to 0 … 4,000 bar (600 bar for UPT-21)
Vacuum ranges -0.2 … +0.2 bar to -1 … +40 bar
Output signals:
4 … 20 mA
4 … 20 mA with HART® signal
Measurement accuracy:
0.15 % (standard)
0.1 %
0.2 %
Turndown:
Up to 5:1, if the data sheet specifications are maintained
Recommended up to 30:1 with restricted basic accuracy

Communication:
DD, EDD, DTM* in download area of www.wika.de
Wetted parts:
Stainless steel
Model UPT-21: Sealings from NBR, EPDM, FKM
Case material:
Precision-cast stainless steel, optional with electropolished surface
Approvals*:
ATEX II 1/2G Ex ia IIC T3..T6, for further approvals see data sheet
Data sheet:PE 86.05

Process connection:
Standard model UPT-20: G ½ B, ½ NPT, M20 x 1.5, ½ NPT female
Flush model UPT-21: G ½ B, G 1B, G 1 with hygienic connection
Display:
With 4 ½-digit LC display (optional without display)

Robust caseWith its stainless steel case, and particularly also due to its
surface, the UPT is optimally suited for use in hazardous
areas. Through its specific protection against dusts andliquids, with IP66 (splash-proof) and IP67 (temporaryimmersion), the instrument is ideal for outdoor applications.

5

IPT-21 with flange connection andelectropolished stainless steel case

IPT-20 with aluminium
double chamber case

Large variety of cases
The IPT industrial process transmitter and the CPT trans­mitter with ceramic measuring cell are available in sevencase variants. The choice of case materials is between
plastic, aluminium and stainless steel.

Plastic,
single or double chamber case

6In particular, the requirements on explosion-proof cases
for explosion protection is catered for here with two casevariants (aluminium and stainless steel castings).

Aluminium,
single or double chamber caseElectropolishedstainless steel

Precision-cast stainless steel,single or double chamber caseIndustrial process transmitter
Models IPT-20, IPT-21 with metal measuring cell
Models CPT-20, CPT-21 with ceramic measuring cell

Specifications
Measuring ranges:
Absolute pressure 0 … 0.1 bar to 0 … 60 bar
Gauge pressure 0 … 0.1 bar to 0 … 4,000 bar (600 bar for IPT-11)
Vacuum ranges -0.05 … +0,05 bar to -1 … +60 bar
Output signals:
4 … 20 mA
4 … 20 mA with HART® signal
4 ... 20 mA / HART® with SIL 2 qualification
FOUNDATION™ Fieldbus
PROFIBUS® PAMeasurement accuracy:
0.05 % with ceramic measuring cell0.075 % with metal measuring cell
Turndown:
Up to 5:1, if the data sheet specifications are maintained
Recommended up to 30:1 with restricted basic accuracy
Process connection:
IPT-20 and CPT-20: G ½ B, ½ NPT, ½ NPT female, M20 x 1.,5, M16 x 1.5
female, 9/16-18 UNF female
IPT-21 and CPT-21: G ½, G 1, G 1 ½, G 1 hygienic to 150 °C and manyfurther connections

Communication:
DD, EDD, DTM* in download area of www.wika.de
Wetted parts:
Stainless steel
Hastelloy
Elgiloy
Oxide ceramic for ceramic cells
Various sealing materialsCase material:
PlasticAluminium
Electropolished stainless steel
Precision-cast stainless steel
Approvals:
ATEX II 1G, 1/2G, 2G Ex ia IIC T6
ATEX II 1/2G, 2G Ex d ia IIC T6
ATEX II 1/2D, 2D IP66/67 T
Data sheet:PE 86.06 and PE 86.07

Display:
With 5-digit LC display (optional without display)

Electronics

Sensors

The electronics are available in four variants with ananalogue output and three bus variants. In this way,
all standard output signals in the process industry arecovered.

For the optimal match to the customer's process, there is achoice between three different sensor types. For the piezo
and thin-film sensors, the wetted surfaces are from stainlesssteel or Hastelloy. These two sensor types are welded on theprocess side, so that no sealing is required at the sensor.
The advantage of the ceramic measuring cell lies in the highoverload safety, the low abrasion characteristics and thehigher accuracy.

Piezo

Thin film

Ceramic7

DPT-20 with two 990.27 flange-type diaphragm seals assembled via capillaries

DPT-20 with aluminium double
chamber case in Ex d design

While the models UPT and IPT can be used for relative and absolute pressure measurements, the model DPT-20 isavailable for differential pressure measurements. Typical applications are pump and filter monitoring and also leveland flow measurement.

Level measurement
A common application is the monitoring of a closed vessel, in
which the overlying gaseous phase must be subtracted fromthe hydrostatic pressure of the vessel contents. This is theonly way (along with the information about the density of thecontents) to get the correct filling height.
Furthermore, if the vessel's geometry is known, then eventhe volume can be calculated. This information can also beentered into the transmitter as a parameter. The transmittercan calculate user-defined tank geometries and indicate thevolume directly on the display.

8

Closed reactor with heating
and stirrer, DPT-20
connected via flanged
diaphragm seals

Differential pressure transmitter
Model DPT-20

Specifications
Measuring ranges:
Differential pressure -10 ... +10 mbar to -16 ... +16 bar
Maximum working pressure (static pressure):
Overload on one side 160 bar or 400 bar
Output signals:
4 … 20 mA
4 … 20 mA with HART® signal
4 ... 20 mA / HART® with SIL2 qualification
PROFIBUS® PA
FOUNDATION™ Fieldbus
Measurement accuracy:
0.065 % with measuring ranges > 0.03 bar
0.1 % with measuring ranges ≤ 0.03 bar
Turndown:
Up to 5:1, if the data sheet specifications are maintained
Recommended up to 30:1 with restricted basic accuracy
Process connection:¼-18 NPT per IEC 61518

Communication:
DD, EDD, DTM* in download area of www.wika.de
Wetted parts:
Process connection: Stainless steel (optional Hastelloy)
Diaphragm: S tainless steel, optional Hastelloy, tantalum, gold-rhodiumcoated Hastelloy, Monel 400®
Sealings: FKM/FPM, NBR, EPDM, copper
Case material:
PlasticAluminium
Electropolished stainless steel
Precision-cast stainless steel
Approvals:
ATEX II 1G, 1/2G, 2G Ex ia IIC T6
ATEX II 1/2G, 2G Ex d ia IIC T6
Data sheet:PE 86.22

Display:
With 5-digit LC display (optional without display)

Flow measurement

The combination of the model DPT-20 with primary flow
elements makes it possible to measure the flow in pipes.
It is important to design the assembly so that the orificegeometries generate a differential pressure thatcan be optimally converted into a flow value by
the measuring instrument. The resulting pressure
differential is measured before and after theorifice with a DPT-20 which is connected via a
3-way valve. Primary flow elements are alsopart of the WIKA product portfolio.

Pipe cross-section withflow of a gas througha defined constriction(orifice)

Orifice with flanged welding
sockets9

Kommunikation mit
Prozesstransmittern

Fieldbus systems in process control
technology
Process Control Systems (PCS) are observing units that fully
monitor, manage and control industrial plants (for example).
All parameters and measured data related to the process aretransmitted to a central point and evaluated according to adefined algorithm.
A purely analogue output signal only enables the communication from the measuring instrument for control. With
process transmitters with fieldbus interfaces, further possibilities are offered. The digital bus signal, or also the HART®
protocol, enables bidirectional communication. The operator
thus has the possibility to request specific parameters and, ifnecessary, also to change them. Therefore, for example, themeasuring span of a process transmitter can be matched tothe process without needing any service personnel.

10A bus instrument offers a further sizeable advantage:Through the scalability in the process or in the laboratory,a measuring instrument can be exchanged when it malfunctions and the stored data easily transferred to the newinstrument. Through the reduction in service time and downtime connected with this, the operating costs can clearly beoptimised.

Freely scalable

For the WIKA UPT, IPT and DPT process transmitters, werecommend turndown values of up to 30:1. The stated basic
accuracy is maintained to a max. of 5:1. Through cleverselection of stock, this enables several applications to becovered with the same basic measuring range.

DTMs (Device Type Managers)
Alongside the primary value (PV), the digital bus instruments
also enable further values to be passed on to the instrumentsthat relate to the same data loop. This therefore offers thepossibility, for example, to react to a rising temperature value
in a sensor. Likewise, the instrument can output alreadycalculated values such as level in units of length and volumein litres (for example). This requires a continuous input ofprocess data and the possibility to be able to change theinstrument parameters easily.
Such possibilities are offered by DTMs (Device TypeManagers), which are specially programmed for this andspecifically matched to the WIKA instruments. If there is noprocess control system available, it is enough for the user tohave an FDT program (Field Device Tool) such as PACTwareon their laptop. By loading the DTM, users can communicate
with the instrument in the full scope of their application.
However, the communication capability of the WIKA processtransmitters is also ensured with other process control systems. A data description (DD, EDD), which − comparable toa printer driver in PC systems − is needed in order to operate
the instrument with any process control system, can be foundin the download area of www.wika.de.

Pactware

Pactware with the WIKA DTM for IPT, page for adjustment of thelinearisation function, the top illustration shows the tank data
calculation program

HART® modem
Open, manufacturer-independent andfielbus-independent user interface
for operation and parameterisation offieldbus devices.

For communication between PC ornotebook and the process transmitter
via the HART® interface (USB, RS232,Bluetooth).

External loop-powered indicator,
model DIH-52
For communication over the HART®
loop, for parameterisation of themeasuring instruments, etc.

11

Accessories
For WIKA process transmitters, there is a comprehensive array of accessories available.

Accessories for all models

Accessories for DPT-20

External display and operating module

Oval flange adapter

Indicator with operator function, can bemounted remotely from the measuring
instrument.

To connect a measuring instrument to apipeline system.

Display and operating unit

Set of screw-in adapters

For simple retrofitting, exchangeable withouttools.

Adapter with ½ NPT thread on theinstrument side and female or male threadon the process side.

Overvoltage protection

Sealing plugs/vent valves

To balance voltage fluctuations.

For venting during the assembly or topermanently close the venting holes.

Repeater power supply

Shut-off valves

For explosion-protected applications,
HART® capable

For shut-off and venting.
As 3-valve or 5-valve manifold.

Mounting accessories
Instrument mounting bracketSyphons

For wall or 2" pipe mounting.

For protection from pulsations in the medium
and from excessive heating.

Welding socket in hygienic design

Barstock valves

Is welded flush with the inner wall in thevessel. For a dead-space free measuring
instrument connection.

For shut-off and venting of the measuring
line.

WIKA Alexander Wiegand SE & Co. KG
Alexander-Wiegand-Straße 30∙63911 Klingenberg∙Germany
Tel. +49 9372 132-0∙info@wika.de∙www.wika.de

14100924 05/2023 EN

In this short video we show the turndown function withprocess transmitters.