halstrup-walcher P29 User guide

Original Instruction Manual for
Differential Pressure Transducer
Type P29 for Natural Gas
halstrup - walcher GmbH
Stegener Straße 10
D-79199 Kirchzarten
Phone:[phone]
Fax: [phone]
E-Mail: [e-mail]
Internet: www.halstrup-walcher.com
Document 7100.004324

P29 Instruction Manual
2
Revision overview
Version:
Date:
Author:
Amendments:
A
Re
Initial Revision
B
09/2014
Me
Screw terminal for output signal as 4-pole
C
07/2016
Me
New display/ user keys
External zero-point calibration as option
D
10/2017
Me
Assembly information (heat/vibrations)
Dimension drawings
certificate of conformity
E
12/2018
MM
Chapter 2.1 Safety concept
Chapter 3.1 Start-up
New LCD(with colours);
F
12/2018
Ka
Change “flammable gases” to “natural gas”
Chapter 2 Safety precautions
Chapter 3 Start up
G
11/2020
Me
Output signal range
Chapter 4.5 added
Update technical data
Dimension drawing
H
06/2022
Me
UKCA
Chapter structure
Chapter 7.3.6 added (Filter)
I
01/2023
Me
Update technical data, Revision Overview; QR-Code
2.2 Notice of Responsibility.
New 2.3 Changes to the device - loss of explosion protection,
New 2.5 Services; 3.1 flush revised,
New 3.3 leak test. 3.3 shipping now 3.4
chapter 10: problem added. All illustrations labelled
New 10.1 Check fuse; New 10.2 Replace fuse
9. Specifications: overload capacity + checks updated
© 2023, Ts
The manufacturer owns the copyright to this instruction manual. It contains technical data, instructions
and drawings detailing the device’s features and how to use them. It must not be copied either wholly
or in part or made available to third parties.
The instruction manual is part of the product. Please read this manual carefully, follow our
instructions, and pay special attention to the safety information provided. This instruction manual
should be available at all times. Please contact the manufacturer if you do not understand any part of
the instructions.
The manufacturer reserves the right to continue developing this device model without documenting
such development in each individual case. The manufacturer will be happy to determine whether this
manual is up-to-date.

P29 Instruction Manual
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Table of Contents:
Purpose of instruction manual.............................................................................................5
Safety precautions...............................................................................................................6
2.1 Safety concept ...............................................................................................................6
2.2 Appropriate use..............................................................................................................6
2.3 Changing to the device...................................................................................................6
2.4 Shipping, assembly, electrical connections and startup..................................................6
2.5 Troubleshooting, maintenance, service, repairs, disposal ..............................................7
2.6 Symbols.........................................................................................................................8
Start-up, maintenance, shipping..........................................................................................9
3.1 Start-up..........................................................................................................................9
3.2 Maintenance, repair .....................................................................................................10
3.3 Leak Test.....................................................................................................................10
3.4 Shipping.......................................................................................................................10
Instrument description.......................................................................................................11
4.1 Features.......................................................................................................................11
4.2 User interfaces.............................................................................................................11
4.3 Internal ports and keys.................................................................................................12
4.4 Front view ....................................................................................................................13
4.5 Readout of volume, mass flow and flow velocity...........................................................14
Zero-point calibration cycle................................................................................................15
5.1 External zero-point calibration......................................................................................15
Overload capacity..............................................................................................................15
LC-Display (optional).........................................................................................................16
7.1 Display.........................................................................................................................16
7.2 Scaling.........................................................................................................................16
Pressure.................................................................................................................16
7.2.1.1 Top...............................................................................................................17
7.2.1.2 Bottom..........................................................................................................17
7.2.1.3 Unit ..............................................................................................................17
Volumetric flow .......................................................................................................17
7.2.2.1 Value............................................................................................................17
7.2.2.2 Unit ..............................................................................................................17
Mass flow................................................................................................................17
7.2.3.1 Value............................................................................................................17
7.2.3.2 Unit ..............................................................................................................18
Flow rate.................................................................................................................18
7.2.4.1 Value............................................................................................................18
7.2.4.2 Unit ..............................................................................................................18
7.3 Warning........................................................................................................................18
Value ......................................................................................................................18
Hysteresis...............................................................................................................19
Tv delay time ..........................................................................................................19
Tn follow-up time (from Rev2.11)............................................................................19

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Warning signal........................................................................................................19
Filter (from Rev2.14)...............................................................................................19
7.4 Settings........................................................................................................................19
Language................................................................................................................19
Output.....................................................................................................................20
Filter........................................................................................................................20
Warning signal........................................................................................................20
Resolution...............................................................................................................20
Zero-point calibration..............................................................................................20
CS (creep suppression) ..........................................................................................20
Lightning.................................................................................................................20
Colour change ........................................................................................................20
Brightness.............................................................................................................20
Contrast................................................................................................................21
Read factory settings ............................................................................................21
Code?...................................................................................................................21
List of commands..............................................................................................................22
Technical data...................................................................................................................24
Trouble shooting / Servicing............................................................................................25
10.1 Checking the fuse ......................................................................................................25
10.2 Replacing the fuse .....................................................................................................26
Dimension drawing..........................................................................................................27
Menu tree (display option)...............................................................................................28
Certificate of Conformity..................................................................................................30

P29 Instruction Manual
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Purpose of instruction manual
This instruction manual describes the features of the P29 and provides guidelines for its use.
Improper use of this instrument or failure to follow these instructions may cause injury or
equipment damage. Every person who uses this device must therefore read the manual and
understand the possible risks. The instruction manual, and in particular the safety precautions
contained therein, must be followed carefully.
It is especially important to read and follow the notes on starting up in systems that use
flammable gases.
Contact the manufacturer if you do not understand any part of this instruction manual.
Handle this manual with care:
It must be readily available throughout the lifecycle of the instrument.
It must be provided to any individuals who assume responsibility for operating the instrument
at a later date.
It must include any supplementary materials provided by the manufacturer.
Conformity
This device is state of the art.
It complies with the statutory requirements of the EC and UK-directives. This is
documented by the CE and the UKCA mark being affixed.

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Safety precautions
2.1 Safety concept
When using in systems with natural gas, the entire pressure system must be flooded with the
gas before switching on the electrical power supply. This creates a non-explosive atmosphere
in the gas-carrying system of the unit.
During operation, both pressure ports must be connected to the pressurized system.
The P29 has been subjected to an ignition hazard analysis according to DIN EN 1127-1:2019.
Under normal operating conditions, there is no explosive atmosphere in the transducer.
Consequently, it has no ATEX label, as it does not fall within the sphere of application covered
by Directive RL 2014/34 /EU.
2.2 Appropriate use
The instrument may only be installed outside potentially explosive atmosphere.
The P29 is used to measure differential pressure, volumetric flow, mass flow and flow velocity
using the orifice plate. It may be used in systems with natural gas provided that the
commissioning rules described in Section 3 are observed.
The operator of the device is responsible for supplying a pure (oxygen-free) fuel gas
atmosphere (natural gas). The manufacturer is not liable for damage resulting from
improper or non-intended use.
Always observe the operating requirements –particularly the permissible supply voltage –
indicated on the rating plate and in the “Technical data” section of this manual.
The instrument may only be handled as indicated in this manual. Modifications to the
instrument are prohibited. The manufacturer is not liable for damages caused by improper use
or failure to follow these instructions. Violations of this type render all warranty claims null and
void.
2.3 Changing to the device
The device may only be handled in accordance with these operating instructions. Modifications
to the device are not permitted. The manufacturer is not liable for damage resulting from
improper or non-intended use. In this case, the warranty claims also expire.
If the device is used improperly or not for its intended purpose, there is a risk of the
device losing its explosion protection effect.
2.4 Shipping, assembly, electrical connections and startup
Assembly and the electrical connections should only be handled by trained professionals. They
should be given proper training and be authorised by the operator of the facility. This applies
particularly to systems that work with natural gas. Special start-up rules (Section 3) apply in
this area.
The following ignition hazards must be taken into account during installation:
“Hot gases” The gas temperature of the natural gas must be within the permissible
ambient temperatures of the unit. If necessary, ensure sufficient cooling or heating of
the gas or mount the unit in a location where the natural gas has assumed the ambient
temperature of the unit.

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“Spontaneous ignition of dust” The unit must not be mounted in a dust Ex zone
(zone 20, 21 or 22).If heavy dust deposits areto be expected on the unit, please ensure
regular cleaning with a damp cloth.
“Lightning” Do not mount the unit and its supply lines outdoors. Ensure sufficient
overvoltage protection of the supply voltage.
Although the P29 pressure transducer is highly robust, it is nevertheless a precision instrument
and should be handled with care. Avoid mounting the P29 in the direct vicinity of any sources
of heat or radiation. Ideally, the instrument should be mounted vertically on a wall not subject
to vibration.
The instrument may only be operated by appropriately trained individuals who have been
authorized by the operator of the facility.
Do not carry out a function test with compressed or breathable air. This would damage
instruments with low measuring ranges.
Measurement errors may occur if the instrument is not kept protected from sunlight.
Specific safety precautions are given in individual sections of this manual.
2.5 Troubleshooting, maintenance, service, repairs, disposal
The individuals responsible for the electrical connections must be notified immediately if the
instrument is damaged or if errors occur that cannot be corrected as indicated in Section 10
This individual must take the instrument out of service until the error has been corrected and
ensure that it cannot be used unintentionally. In systems operating with flammable gases, the
instrument must be separated from the gas supply lines.
Always switch off the power to the instrument before opening!
This instrument requires no maintenance. Only the manufacturer may perform repairs that
require the housing to be opened.
The electronic components of the instrument contain environmentally hazardous materials and
materials that can be reused. The instrument must therefore be sent to a recycling plant when
you no longer wish to use it. The environment codes of your particular country must be
complied with.

P29 Instruction Manual
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2.6 Symbols
The symbolsgiven below are used throughoutthis manual toindicate instances when improper
operation could result in the following hazards:
WARNING! This warns you of a potential hazard that could lead to bodily injury up to
and including death if the corresponding instructions are not followed.
CAUTION: This warns you of a potential hazard that could lead to significant
property damage if corresponding instructions are not followed.
INFORMATION: This indicates that the corresponding information is important for
operating the instrument properly.
RISK OF EXPLOSION! This shows measures to prevent explosions, which must be
observed.

P29 Instruction Manual
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Start-up, maintenance, shipping
Caution: Explosion hazard! Flush the system for the required period of time before
start-up!
3.1 Start-up
Carefully read and follow the start-up instructions listed below. Failure to follow these
instructions can lead to an explosion in the instrument and injury to persons.
Installation and start-up of the instrument may only be performed by persons trained
in handling equipment in areas with explosion hazards.
The instrument must be separated from the electrical power supply during the following steps:
Install the instrument in the system (only outside potentially explosive atmosphere) -
do not connect to the gas line at this time.
Install all connecting electrical cables (powerless) in the instrument
Test the functions
oCheck the flow between plus and minus pressure connection
(check the preflush function)
oApply supply voltage
oBriefly check pressure measurement function
oSwitch supply off again
Tighten high strength cable glands
Unused high strength cable glands must be sealed
Close the housing
Before connecting the instrument to the gas lines, both pressure lines should be flooded
with gas otherwise the instrument itself must be flooded with gas for a longer period of time.
Appropriate equipment must be installed for this purpose
Flushing process
oClose gas supply lines
oAttach both pressure connections
oTighten the terminals on the gas supply lines and check them
oApprove gas supply lines for use
oFlood the device with gas for at least 6 minutes when it is switched off. To do
this, there must be a differential pressure at the pressure connections. Notice
the maximum system pressure see 9.Technical data.
oOnly then may the electrical power supply to the instrument be switched on again
This start-up regulation has the purpose of flushing the oxygen required for combustion out of
the instrument so that only a pure gaseous atmosphere is present. This gas atmosphere
cannot ignite because no oxygen is present. This entire start-up procedure must be repeated
if the instrument is separated from the gas supply line even for only a short period of time.
Consequently, both pressure ports must be connected to the pressurized system during
operation.
The device may not be used in systems with natural gas unless this startup
regulation is observed.

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3.2 Maintenance, repair
Maintenance and repair work may only be performed by trained professionals and
on behalf of the operator of the plant.
The following steps must be performed before beginning maintenance work:
Separate the instrument from the electrical power supply.
Close gas supply lines.
Detach the gas supply lines.
Open the instrument.
Detach electrical connections.
Remove the instrument.
Flush the switched-off pressure system for at least 2 minutes with air
(P = 100…1000mbar) to remove the gas.
Install and start-up the new instrument as described in Section 3.1.
3.3 Leak Test
If necessary, the user can carry out regular leak tests as a simple pressure test.
For the leak test, shut off the two pressure lines to the P29 and note the initial pressure (display
or output signal). Observe the differential pressure for 1 minute. The differential pressure must
not drop over this period. Please note that strong temperature fluctuations in the confined
volume can also lead to changes in pressure.
3.4 Shipping
Instruments operated with natural gas can still contain remnants of these gas. These
must be flushed out before packaging.
To ensure that there are no more gas residues in the device, once the device has been
installed in a system that works with natural gas, it must be switched off for at least 2 minutes
and connected to the plus or minus pressure connection with air (P = 100…1000mbar)
in order to remove all traces of the gas. This is particularly important if several instruments are
to be shipped in the same box.

P29 Instruction Manual
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Instrument description
4.1 Features
The P29 is controlled by a microprocessor and can perform the following tasks:
Measurement of differential pressure
Measurement of volumetric flow, mass flow and flow rate using the orifice plate
Display of a measured value
Monitoring of a variety of threshold parameters
The instrument may be used in systems with natural gas under strict observance of
the methods stated in Section 3
-
+
Actual pressure value
Calculation:
Volumetric flow
Mass flow
Flow rate
µC
Pressure measurement
Valves
pos. pressure
neg. pressure
Display Serial
interface
Relay
Keyboard
Analogue output signal
figure 4-1 functional description
4.2 User interfaces
The following four keys are available:
Menu UP Right Enter
Key
Meaning (Measurement Mode)
Meaning (Menu)
Menu
Start Menu
Go back a menu level
Enter
Start zero-point calibration
Confirm
Up arrow
Max. display
Increases a value or scrolls up
Right
arrow
Min. display
Moves the arrow or scrolls down
In measurement mode, the keys perform the following functions:
The Enter key starts a zero-point calibration
▲- key shows the maximum (to reset: press Enter while the maximum is being displayed)
►- key shows the minimum (to reset: press Enter while the minimum is being displayed)
When the air consumption function is activated, the keys perform the following functions:
The Enter key starts a zero-point calibration

P29 Instruction Manual
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Press the “▲“ key to display the current mass or volume flow.
Press the “►“ key to display the current value for the operating hours meter.
4.3 Internal ports and keys
figure 4-2 Internal connectors and push buttons
Output signal Power supply
figure 4-3 circuit board
RS232 interface for parameterisation Reset

P29 Instruction Manual
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Output signal:
No.
Designation
Description
Signal range
1
I
current output 0 …20 mA
current output 4 …20 mA
0,00 mA…20,75 mA
4,00 mA…20,00 mA
2
GND
earth
3
U
voltage output 0 …10V
voltage output -5V …+5V
-2,0V…+12,0V
-5,0V…+7,0V
4
N
+24V starts external
zero-point calibration
Power supply:
No.
Designation
Description
11
GND
Ground
12
+24VDC
Power supply + 24VDC
13
RS232 interface for PC:
RS232 interface for parameter settings
Reset:
The processor is restarted.
4.4 Front view
Cable glands:
Signal Supply
Pressure ports: + -
INFORMATION:
The best measuring accuracy is achieved at a room temperature of 20°C.
figure 4-4 front view

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4.5 Readout of volume, mass flow and flow velocity
With square-root extracted output signal, the assignment of differential pressure volume, mass
flow or flow velocity can be set via the serial interface with a PC software or, for instruments
with display, via the menu using the four keys in the top cover.
The calculation of the analogue output and the display (for instruments with display) is done
according to the following formulas:
Calculation of the analogue output 0 - 20 mA or 4 - 20 mA:
 


󰇗    


Calculation of the analogue output 0 - 10 V:
 


Calculation of the display for volume flow, mass flow or flow velocity:
󰇗󰇗

󰇗 󰇗  󰇗 

󰇗 󰇗  󰇗


Thereby is:
 the (internal) measured value for the differential pressure (in the selected unit, e.g.
Pa)
 the (adjustable) scaling end value of the differential pressure =
"Scale Top" (in the selected unit, e.g. Pa).
"Scale Bottom" must always be 0 when the output is square-rooted.
 , for example, is the differential pressure value generated by a dynamic
pressure probe at volume flow 󰇗
 Analog current output signal (0 - 20 mA or 4 - 20 mA)
 Analog voltage output signal (0 - 10 V)
󰇗 the (adjustable) volume flow value to be displayed at a differential pressure of 
= "Vol. flow. at max. scaling value" (in the selected unit, e.g. m³/h)
󰇗the displayed volume flow value (in the selected unit, e.g. m³/h)
󰇗  the (adjustable) mass flow value to be displayed at a differential pressure of  =
"Mass flow” at max. scaling value" (in the selected unit, e.g. kg/s)
󰇗 the displayed mass flow value (in the selected unit, e.g. kg/s)
󰇗 the (adjustable) flow velocity value to be displayed at a differential pressure of 
= "Flow rate” at max. scaling value" (in the selected unit, e.g. m/s)
󰇗 the displayed flow velocity value (in the selected unit, e.g. m/s)
In addition, a low flow suppression (LFV) can be set as a percentage of the nominal pressure
range. If the measured pressure value falls below this limit, the output is set to zero. This
avoids strongly fluctuating (square-rooted) output values at very small pressure measuring
values.

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Zero-point calibration cycle
External influences such as temperature, position or ambient pressure can shift the
instrument’s zero point, i.e., the value displayed when the pressure ports are open. During
calibration, the instrument automatically calculates this shift and takes it into account during
the zero-point calibration.The zero-point calibration takes place in two steps, which are shown
in the top line of the display (optional).
“0” Measuring signal of the zero point is being determined.
“P” Pressure is being reconfigured
The interval between two zero-point calibrations can be adjusted in the Settings menu.
Zero-point calibration can also be started with the Enter key if the device is in Measurement
mode.
The P29 does not respond to keys being pressed during calibration.
5.1 External zero-point calibration
In order to trigger an external zero-point calibration, connection 4 at the output connector must
be briefly connected to +24V.
If a zero point adjustment is called up via the serial interface or the external zeroing input, it will
be carried out in any case. It is irrelevant whether the zero point adjustment has been
deactivated or the P29 is in the menu mode.
Overload capacity
The P29 has an internal overpressure safeguard that protects the precision pressure
measurement capsule from damage:
100 kPa for measurement ranges ≥ 2,5 kPa
200 x for measurement ranges < 2,5 kPa

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LC-Display (optional)
The measured values and the menu are shown on the display. The top line is the information
line. This line displays the type of measured value or the status of a zero-point calibration. The
measurement value will be displayed on the central line. If the permitted measuring range is
exceeded or not reached, the figures are replaced by corresponding arrows. The bottom line
displays the unit, with the first two digits showing the status of the two warning messages.
Press the Menu key “ “ to bring up the menu.
In Menu mode, the parent menu item always appears in the top display line. The middle line
always shows the current sub-menu item or value to be changed. The bottom line displays
units or other help texts.
Start the Menu mode by pressing the "Menu" key. It can be protected with a four-character
password. At the main menu level, “Menu” is displayed in the top line and “Display” in the
middle line. Select your desired sub-menu by pressing the “▲“ and “►“ keys. Press “Enter” to
go to a sub-menu or enter a value. Press the “Menu” key to go to the next menu level or to
stop entering values.
The following sub-menus are available in the first level:
Display
Scaling
Warning
Settings
7.1 Display
The display unit can be selected with this menu item. Press the “▲“ and “►“ keys to select the
unit you want and press “Enter” to confirm. The type of display (pressure, flow rate etc.) is
selected automatically.
The following units are available:
Pa
hPa
kPa
mbar
mmH²O
mmHg
psi
inH²O
inHg
m³/s
m³/h
kg/s
kg/min
kg/h
m/s
mph
f/s
f/min
km/h
7.2 Scaling
The P29 is usually supplied with standard measuring ranges. You can use the scale to adjust
the measuring range for your own use. The output voltage or currents are then copied to this
scaled range. The scaled range should always be more than 0.1 times of that of the P29’s
measuring range, because otherwise the resolution of the outputs and the accuracy will be
poorer.
With this menu item, there are 4 sub-menu items:
Pressure
Volumetric flow
Mass flow
Flow rate
Pressure
This is an important menu item. It is used to specify the pressure range, which indicates the
output value. This pressure range forms the basis for many other settings such as the limits
for the warnings and factors for the flow display.
There are two default settings for the pressure scale:
Top = Pressure at which the output has its maximum value (e.g. 5V, 10V or 20 mA)
Bottom = Pressure at which the output has its minimum value (e.g. -5V, 0V, 0mA or 4mA)
Because the values can be freely assigned, settings such as 0V at 0Pa or 10V at -250Pa are
also possible.

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7.2.1.1 Top
With this menu item, you can set the pressure at which the output will achieve its maximum
value. Anyvalue within the measuring range can be selected. It can also beless than the lower
scale value.
7.2.1.2 Bottom
With this menu item, you can set the pressure at which the output will achieve its minimum
value. Any value within the P29’s measuring range can be selected.
7.2.1.3 Unit
Use this menu item to select the pressure unit. The following pressure units can be selected:
Pa
hPa
kPa
mbar
mmH²O
mmHg
Psi
inH²O
inHg
Volumetric flow
This menu item is used to adjust the volumetric flow display values.
The following sub-menu items are available:
Value
Unit
7.2.2.1 Value
This is used to set the volumetric flow value displayed at the maximum scaled pressure. 0 is
always used as the lower scale value on the volumetric flow display (root-extracted measured
value). The maximum pressure is the larger of the two scale values, which is used as a basic
calculation.
7.2.2.2 Unit
You can use this menu item to select the unit of the volumetric flow value. The following
volumetric flow units can be selected:
m³/s
m³/h
Mass flow
This menu item is used to adjust the mass flow display values.
The following sub-menu items are available:
Value
Unit
7.2.3.1 Value
This is used to set the mass flow value displayed at the maximum scaled pressure. 0 is always
used as the lower scale value on the mass flow display (root-extracted measured value). The
maximum pressure is the larger of the two scale values, which is used as a basic calculation.

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18
7.2.3.2 Unit
You can use this menu item to select the mass flow unit. The following mass flow units can be
selected
kg/s
kg/min
kg/h
Flow rate
This menu item is used to adjust the flow rate display values.
The following sub-menu items are available:
Value
Unit
7.2.4.1 Value
This is used to set the flow rate value displayed at the maximum scaled pressure. 0 is always
used as the lower scale value on the flow rate display (root-extracted measured value). The
maximum pressure is the larger of the two scale values, which is used as a basic calculation.
7.2.4.2 Unit
Use this menu item to select the flow rate unit. The following flow rate units can be selected:
m/s
mph
f/s
f/min
km/h
7.3 Warning
INFORMATION:
For safety reasons, relay outputs are not possible with the P29. However, exceeding or falling
below the switching thresholds can be signalled visually and acoustically.
Use this menu item to set the warning values. The first menu item that appears here is Select
Warning Message (1 or 2). The settings for this warning message should then be changed.
Use the “▲“ and “►“ keys to select the number of the warning and press Enter to move to that
warning's menu.
The following sub-menu items are available:
Value
Hysteresis
Tv
Tn
Warning signal
Filter
Value
This item adjusts the pressure value at which the particular warning should be activated. The
pressure range defined by the scale can be used as the setting range. Select the pressure unit
set for the display as the unit. If the volumetric flow, mass flow or flow rate (root-extracted
display) is displayed, select the Pa unit.

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Hysteresis
This item can be used to select the hysteresis for the particular warning. The action described
in 7.3.1 applies to the entry unit. The hysteresis is always positive.
Tv delay time
The entry value of the warning is derived from the unfiltered pressure value. With this
parameter, you can now specify how long the pressure value can be exceeded or not met until
the warning is activated. The adjustment is done in ms. 25 ms is specified as the minimum
value.
Tn follow-up time (from Rev2.11)
The entry value of the warning is derived from the unfiltered pressure value. With this
parameter it can now be specified how long the warning remains activated after the pressure
value is again within the range in which the warning is not active. The adjustment is done in
ms.
Warning signal
A warning signal sounds once every second when a threshold value is exceeded. With this
parameter, you can set the duration of this warning signal for each warning. The maximum
value here is 1000 ms (continuous tone). If both warnings are active, the longer warning signal
of the two sounds. The warning signal may sound different depending on the activation level.
A warning signal duration of 0 ms switches the signal off.
Filter (from Rev2.14)
This item can be used to adjust whether the warning is to be activated when the pressure
exceeds or falls below the warning pressure threshold. This affects the processing of the
hysteresis value.
7.4 Settings
With this menu item, you can adjust various parameters that affect the instrument’s behaviour.
The following sub-menu items are available:
Language
Output
Filter
Warning signal
Resolution
Zero-point calibration
CS (creep suppression)
Lightning
Colour change
Brightness
Contrast
Read factory settings
Code?
Language
The menu language can be selected with this menu item. You can choose from the following
languages:
English
German
Italian
French
Make your choice with the “▲“ or “►“ keys. Press Enter to confirm your selection.

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Output
With this parameter, you can select the output and output range. You can choose from the
following options:
4 … 20 mA
0 … 20 mA
-5V … +5V
0V … 10V
Filter
The measured pressure values can be smoothened by a filter before they reach the display or
analogue output. This parameter lets you set a time constant for this filter.
Warning signal
With this parameter, the signal that a key has been pressed can be switched on or off.
Resolution
This parameter affects the display resolution. The display is changed according to the adjusted
values. For example, if the setting is 1%, the display changes to showing the measuring range
in 1% jumps. This can be used with severely fluctuating pressures to steady the display.
However, this does not have any affect on the warnings.
Zero-point calibration
This parameter specifies the time interval for the automatic zero-point calibration. The entry is
in min. Setting the parameter to 0 deactivates automatic zero-point calibration.
CS (creep suppression)
This parameter specifies the value for creep suppression as a percentage. If this value falls
short of the measured pressure value, the display is set to zero. Creep suppression only works
with volumetric flow, mass flow and flow rate (root-extracted measurement values).
Lightning
With this parameter, the colour of the backlight of the LC display, in the menu or when the
colour change is switched off, can be selected. There are three options to choose from:
off backlight is switched off
white backlight is white
blue backlight is blue
Colour change
This parameter can be used to select whether or not the display background changes colour
when a limit value is exceeded. There are two options to choose from:
off colour change is switched off
on colour change is active
When a value set in the warnings is exceeded, the display turns yellow for the time Tv or Tn
and then changes to a red backlight after the warning is active.
Brightness
With this parameter, the brightness of the backlight can be set. Values between 0( dark) and
16( bright) are possible.