Lambrecht 8126 X81 User manual

1(8126 X81) Precision Air Pressure Sensor Operating Instructions
Operating Instructions
Precision Air Pressure Sensor (8126 X81)
Precision Air Pressure Sensor
8126 X81

2 (8126 X81) Precision Air Pressure Sensor Operating Instructions
Operating Instructions
Precision Air Pressure Sensor (8126 X81)
Contents
1.0 Description
1.1 General
1.2 Dimensional drawing
1.3 Function
1.4 Interface Specification
2.0 Putting into operation
2.1 Choice of installation place
2.2 Mounting
2.3 Electrical connection
2.4 Cable entries
2.5 Setting into operation
2.6 Performance check
3.0 Service and maintenance
3.1 Periodical works
3.2 Change of spare parts
3.3 Spare parts drawing
3.4 Spare parts list
3.5 Ordering of spares
4.0 Setting out of operation
4.1 Storage
4.2 Dispatching
5.0 Warranty
6.0 Technical data

3(8126 X81) Precision Air Pressure Sensor Operating Instructions
Operating Instructions
Precision Air Pressure Sensor (8126 X81)
1.0 Description
1.1 General
This high-precision air-pressure sensor (8126 X81) is de-
signed with a microprocessor controlled sensor working on the
resonance principle. The signal output is realised by means of
a serial port of RS 485 standard to be linked to a LAMBRECHT
data logger SYNMET or Ser[LOG].
The cable entry is carried out by an incorporated cable inlet
according to VG 88 812. Signal and power cables are fixed
by means of screw terminals. It is constructed as a primer
coated seawater resistant aluminium housing which normally
is painted with a grey (RAL 7001) lacquer.
To fulfil the strong EMC/EMI requirements the housing is
equipped with conductive rubber sealing and metallic cable
inlets according to VG 88 812. To meet the shock and vibration
requirements the housing is furnished with reinforced brackets
made of stainless steel.
1.2 Dimensional drawing
1.3 Function
The RS 485 output signals of the precision air-pressure sensor
(8126 DPS) are linked to the LAMBRECHT interface system
SYNMET-NAV for further evaluation and supply to other sys-
tems. Due to the excellent accuracy of ± 0.01 % full scale the
sensor can be used for aviation purposes. In order to enable
the outer air its necessary access to the incorporated pressure
probe the housing is equipped with a filtering inlet located on
the underside.

4 (8126 X81) Precision Air Pressure Sensor Operating Instructions
Operating Instructions
Precision Air Pressure Sensor (8126 X81)
1.4 Interface Specification
After a few seconds the power has been applied the trans-
ducer starts automatically sending measuring values.
The pressure transducer continuously transmits data
every second.
Interface: RS485
The communications settings are:
Baud rate: 9600
Parity: N (none)
Character length: 8
Stop bits: 1
No handshaking
Format: ASCII text
The pressure value is send as floating point number inASCII
format. The floating point pressure value is followed by a
space character and the unit “hPa”
Every transmitted measuring value ends with 2 termination
characters <CR><LF>.
Example:
1018.82 hPa<CR><LF>
in hex-code:
31 30 31 38 2E 38 32 20 68 50 61 0D 0A
(<CR>= carriage return = 0x0D)
(<LF>= line feed = 0x0A)
Power supply: 11…28 VDC
Current typ. 16 mA max.32 mA
Interface: RS485
Failure message
In case of failure the transducer sends error messages.
The error message starts with “!” followed by a three-digit
number.
Every transmitted error message ends with 2 termination
characters <CR><LF>.
Example:
!020<CR><LF>
in hex-code:
21 30 32 30 0D 0A

5(8126 X81) Precision Air Pressure Sensor Operating Instructions
Operating Instructions
Precision Air Pressure Sensor (8126 X81)
2.0 Putting into operation
2.1 Choice of installation place
As a barometer needs a free access to the ambient outer air
it has to be installed outdoors without influence of pressure
oscillations caused by movements of the vessel. Therefore
the sensitive barometer should be installed on a place which
is located at a wind protected place. In general the housing is
splash-water tight when mounted correctly. Therefore the air
inlet of the housing has to show downwards in order to prevent
the penetration of sea and rain water.
As barometric pressure values world-wide are based on
measurements above sea level the altitude of the barometer
should be noted for later compensations. Otherwise wrong
measurements of approximately 1 hPa per 8 m height have
to be considered.
In case of the instrument has to be installed indoors due to
special requirements a pressure link to the outer atmosphere
has to be carried out by means of a flexible rubber pipe or
a similar material. Otherwise overpressure cause by air-
conditioners will falsify the measurements.
2.2 Mounting
The mounting must be carried out on a flat surface with four
stainless steel hexagonal screws of the size M8.
2.3 Electrical connection
The electrical connection (drawing see right site) must be
carried out in the external junction box according to the wir-
ing diagram of the entire system. Important note: To prevent
electrical hazards for installation staff and damages due to
short circuits, it is absolutely necessary to switch off the main
power supply of the system until the installation is finished.
Attention: wrong connection may cause a destruction of this
and other connected components !
2.4 Cable entries
The common signal and power cable will be linked inside the
housing by means of a cable gland according to VG standards.
The selection of the right cable inlet will be carried out accord-
ing to the project specific bloc diagram respectively the wiring
diagram. The corresponding positions are clearly illustrated in
the discussed drawings.As only one item is present a special
identification procedure is not required.
For various outer diameters of the installation cables different
sized cable cones will be delivered together with the item.
2.5 Setting into operation
After having finished the electrical and mechanical installation
work of this item as mentioned in this manual and other related
instructions the wiring should be checked once again before
switching on the mains for the whole measuring system.
No further operating handling is required.
When the power is turned on, the sensor automatically starts
sending data.After a settling time of approx. 20 sec the sensor
provides specification-compliant measured values.
2.6 Performance check
Readings of barometric values can be obtained from the
connected pressure indicators or from external indicator con-
soles. As suitable performance check the read data can be
compared with these of other stations in the neighbourhood.
We recommend to ask a bureau of the local weather service
which should be located in harbours for precise data.
To be able to compare data all pressure values must
be related to the sea level.
Electrical connection
Data
Data
GNWTRDBU
Output A Green
RS485 B White
Air pressure
RS485 half-duplex
11...28 V DC
(24 V nominal)

6 (8126 X81) Precision Air Pressure Sensor Operating Instructions
Operating Instructions
Precision Air Pressure Sensor (8126 X81)
3.0 Service and maintenance
3.1 Periodical works
Apart from periodical visual checks for outer damages of the
housing, water-tightness and the fixing of the mounting screws
no further work is necessary.
3.2 Change of spare parts
All spare parts listed here can be replaced with regular tools
such as wrenches, screw drivers etc.
3.3 Spare parts drawing
Please see chapter 1.3 for illustration.
3.4 Spare parts list
No. Description PPU Order.-No.
-Complete barometer type 08126,
grey colour (RAL 7001) - 00.08126.481 002
1 Screw terminal AKZ 4 KrG 4 65.28030.020 100
2 Cover APKrG 1 65.28020.020 200
3 Designation label (1 to 4) 4 65.28030.020 700
4 End angle EWK1 2 65.28030.020 800
5 Ground insert 21 x 13.6 x 16.5 mm 1 35.88812.220 004
6 Ground insert 21 x 10.6 x 13.5 mm 1 35.88812.220 003
7 Ground insert 21 x 9 x 11.5 mm 1 35.88881.220 002
8 Pressure sensor 8100 1 63.06010.061 000

7(8126 X81) Precision Air Pressure Sensor Operating Instructions
Operating Instructions
Precision Air Pressure Sensor (8126 X81)
3.5 Ordering of spares
In case of spares as mentioned here are required for replace-
ments or to be put on stock the following information are
required to forward the right spare parts to the customer:
name of item and type number•
ordering number/parts number•
required quantity•
related component or name of higher assembly•
type of vessel and country of origin•
reference number of LAMBRECHT wiring diagram des-• ignated with the bold letters SKF.... or SWF.... and a 3 or
4-digits running number.
Adetailed inquiry containing these information will be appreci-
ated by us for the safe identification of the required item(s)
and to prevent wrong deliveries. Above mentioned data can
be obtained from the designation label and from the spares
list of this system component.
4.0 Setting out of operation
4.1 Storage
The sensor should be stored in a clean and dust-free area
between -40 and +85 °C (not condensing) in a cardboard box
or similar container.
4.2 Dispatching
For dispatching we recommend to use a regular cardboard
box and packing material like polystyrene to avoid damages
during transport.
5.0 Warranty
Please note the loss of warranty and non-liability by unau-
thorised manipulation of the system. You need a written
permission from LAMBRECHT meteo GmbH for changes
of system components. These activities must be operated
by a qualified technician.
The warranty does not cover:
1. Mechanical damages caused by external impacts (e. g.
icefall, rockfall, vandalism).
2. Impacts or damages caused by over-voltages or elec-
tromagnetic fields which are beyond the standards and
specifications in the technical data.
3. Damages caused by improper handling, e. g. by wrong
tools, incorrect installation, incorrect electrical installation
(false polarity) etc.
4. Damages which are caused by using the device beyond
the specified operation conditions.

8
08126_X81_b-de.indd 48.17
LAMBRECHT meteo GmbH Tel [phone]
Friedländer Weg 65-67 Fax [phone]
37085 Göttingen E-Mail [email protected]
Germany Internet www.lambrecht.net
Quality System certified by DQS according to
DIN EN ISO 9001:2008 Reg. No.003748 QM08
(8126 X81) Precision Air Pressure Sensor Operating Instructions
Operating Instructions
Precision Air Pressure Sensor (8126 X81)
6.0 Technical data
Cable inlet: according to VG 88 812
Measuring range: 35...2000 hPa
Precision: 0.01 % FS
Accuracy: ± 0.0144 % FS
Long term stability: ± 100 ppm per year
Temperature range: -45...+85 °C during operation
Power supply: 11...28 V DC (24 V nominal)
Current consumption: typically 16.5 mA · max. 32 mA
Colour: grey (RAL 7001) · other colours on
request
Protection class: IP 65 according to DIN 40 050
Dimensions: see technical drawing
Weight: approx. 2.0 kg
Subject to change without notice.
Additional specifications:
Sensor: High precision resonant
pressure transducer
Interface: RS 485 (no bus function)
Update rate: 1 Hz