Van Walt Rain Gauge User manual
Operating Instructions
Van Walt Ltd | Prestwick Lane | Grayswood | Haslemere | Surrey | GU27 2DU | Tel. 01428 661 660 | Fax. 01428 656 808 | www.vanwalt.com
Rain Gauge
1
VAN WALT
Monitoring your needs
MA143V3_02/06/2020_TD
Contents
Introduction ................................................................................................................................
1. Description ........................................................................................................................
1.1 Package contents ...........................................................................................................
1.2 General .............................................................................................................................
1.3 Datalogger .......................................................................................................................
1.4 Measuring section ............................................................................................................
2. Technical specications ..................................................................................................
3. Taking into use ..................................................................................................................
3.1 Settings ..............................................................................................................................
3.2 Connection ......................................................................................................................
3.3 Installation .........................................................................................................................
4. Use ..................................................................................................................................
4.1 LDM e+ ..............................................................................................................................
4.2 Taking rain measurements ..............................................................................................
5. Applications ......................................................................................................................
6. Problems and solutions ....................................................................................................
7. Maintenance ...................................................................................................................
Appendix; Battery set e+ logger ...............................................................................................
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Operating Instructions
Van Walt Ltd | Prestwick Lane | Grayswood | Haslemere | Surrey | GU27 2DU | Tel. 01428 661 660 | Fax. 01428 656 808 | www.vanwalt.com
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VAN WALT
Monitoring your needs
Introduction
The e+ RAIN sensor consists of a datalogger and a separate rain gauge sensor. This manual
describes how to use the datalogger and the rain gauge and what their various functions are. A
description is provided of how to use the Logger Data Manager® (LDM) e+ software. It includes
a guide to the preparation of the software and explains various aspects of its use. This is followed
by a description of the various possibilities available for carrying out rain
measurements. It concludes with instructions for calibration and regular
maintenance.
1. Description
1.1 Package contents
0 e+ RAIN sensor, which consists of a datalogger (11.41.21.01), rain
gauge (11.41.21.02), LDM e+ software (11.11.14) and battery set
e+ logger (11.41.90.01)
0 Available separately:
• Stand for the rain gauge for use in the eld (11.41.92.01), includes special
xing nut.
• IrDa readout unit (11.31.90) for wireless connection with a (laptop)
computer
• Readout unit (11.11.10) for connecting with a (laptop) computer
• DRC Readout cable, for connecting to a (laptop) computer by means
of a DRC communication cable (11.11.45). Available in the following
lengths:
5 m
10 m
15 m
30 m
60 m
80 m
100 m
• e-SENSE e+ sensor cable for connecting to an e SENSE SMS modem (eld
modem) available in the following lengths:
1 m
5 m
10 m
15 m
30 m
60 m
80 m
100 m
200 m
e+ RAIN: datalogger, eld
support and rain gauge
(11.11.38)
(11.11.39)
(11.11.40)
(11.11.41)
(11.11.42)
(11.11.43)
(11.11.44)
(11.31.78)
(11.31.70)
(11.31.71)
(11.31.72)
(11.31.73)
(11.31.74)
(11.31.75)
(11.31.76)
(11.31.77)
Operating Instructions
Van Walt Ltd | Prestwick Lane | Grayswood | Haslemere | Surrey | GU27 2DU | Tel. 01428 661 660 | Fax. 01428 656 808 | www.vanwalt.com
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1.2 General
The e+ RAIN sensor is an intelligent sensor that consists of a specic sensor section as well as a so-
called datalogger that houses the micro-electronics. The datalogger has an internal memory for
storing the measurements but also provides the means for reading the digital data. To make this
1.4 Measuring section
The rain gauge is part of the e+ RAIN sensor and is manufactured from UV-proof
synthetic material. It furthermore has an aerodynamic design which ensures
that measurements suffer as little as possible interference from the wind. The
system operates on the so-called ‘tipping bucket’ method, in which rain is
captured via a funnel and poured into a basin that is xed on a hinge. A pre-
determined amount of rain results in the bucket tipping and emptying itself. Brief
contact results with a switch. In this way the amount of rain equals the number of
switch contacts during a specic time unit. The rain gauge is tted with a 5-pole
connector for connection with the datalogger.
The raingauges tipping bucket mechanism is immobilised before shipping to prevent damage
in transit. To release the mechanism, remove the funnel from its base by unscrewing the three
thumbscrews. Remove the piece of foam from under the bucket mechanism. This foam may be
saved and used whenever the raingauge is moved
1.3 Datalogger
The datalogger is designed around a
microprocessor that performs the role of saving
periodical measurements in the memory and
enables a connected device to read the stored data. The signal
that the sensor part delivers to the interface is converted into data
that can be processed by the microprocessor. The microprocessor
records the data in the memory with a sample speed, based on the
internal Real Time Clock (RTC). It is possible by means of available communication channels,
namely the optical connector and the IrDa link, for a device that has been connected to
communicate with the microprocessor and read the data stored in the memory or adjust
settings such as the sample speed, for instance. The datalogger of the e+ sensor has 2 measuring
channels and the memory range is divided proportionally over the available channels. The
memory has the capacity to store 30.000 measurements per channel.
possible the datalogger has an optical connector for a
communication cable or a readout unit or an IrDa interface for
communication by means of an IrDa readout unit. This offers the
advantage of intercompatibility, reliable transfer of data and
the possibility of stand-alone use.
Operating Instructions
Van Walt Ltd | Prestwick Lane | Grayswood | Haslemere | Surrey | GU27 2DU | Tel. 01428 661 660 | Fax. 01428 656 808 | www.vanwalt.com
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Rain gauge
Diameter rain gauge : 254 mm Height rain gauge
: 340 mm Output signal
: contact
Nominal measurement sensitivity : 0.20 mm rain fall per contact
Maximum contact power : 300 mA Power supply
: None Weight
: 1 kg
3. Taking into use
3.1 Settings
2. Technical specications
Datalogger
Number of channels : 2 channels
Memory capacity : 30,000 measurements per channel
Measurement intervals : 1...60 seconds
: 1...60 minutes
: 1...24 hours
Datalogging method : Measures at chosen times Resolution
: 0.0033%, 15 bit (data storage) Clock accuracy
: <1 sec. per day
Alarm : 0...100% of the measuring range
Battery status : 0 to 100% Temperature operating range
: -20 ... +70 °C Relative humidity range
: 0...100%
Power supply : 3.6 V (AA) lithium battery 2.3 Ah
Battery life : 6 years (typical for 10-minute sample speed)
There is no need to congure any settings before installation of the datalogger. To achieve
optimal measurement precision the datalogger’s factory settings for the range can be used.
The rain gauge is factory-calibrated and is supplied with a calibration specication, which state
the actual measuring sensitivity, the so-called calibration factor. The deviation of this calibration
factor from the nominal sensitivity is 2% at most, which means that the accuracy is always
greater than 2% if the Range setting is not introduced.
Operating Instructions
Van Walt Ltd | Prestwick Lane | Grayswood | Haslemere | Surrey | GU27 2DU | Tel. 01428 661 660 | Fax. 01428 656 808 | www.vanwalt.com
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To be able to congure the datalogger, the following are required: LDM
e+ software, a readout unit (see Chapter 1.1, “Package contents”) and a
(laptop) computer. LDM e+ is a universal software package, suitable for
the e+ datalogger as well as the Diver® from Van Essen Instruments and
can be used for conguration as well as for reading the data. The LDM e+
is simple to install but make sure the user account for installations under
Windows NT, 2000 or XP has adequate access rights for the installation of
software and that the computer being used has a CD-ROM drive. When the CD is placed in the
CD-ROM drive setup will automatically commence. If this is not the case it can be started by going
to Start -> Run, and enter: <X>:\setup.exe, in which <X> will be the letter indicating the CD-ROM
drive. Next connect the readout unit to an available COM port on the computer. Now launch LDM
e+, press the Application Management tab and enter the following settings options:
• Selected port: should show the number of the port to which the readout unit is connected
• User type: in this case Basic is sufcient, only select Advanced if special settings such as the
datalogger units need to be adjusted
• English / Deutsch / Nederlands: this allows you to select the preferred language.
LDM e+ is ready for the conguration of the datalogger, which should now be placed in the
readout unit.
To enter and adjust settings for
the datalogger the appropriate
window can be accessed by
clicking on the Settings tab in
LDM. Before starting, the current
settings for the datalogger rst need to be
entered. This requires clicking on the button
on the toolbar shown on the right. The left-
hand side of the window shows the general
settings for the datalogger (note: for Diver
settings a slightly different window may be shown). In the right-hand section of the window settings
can be created for the 2 individual measuring channels, including the Range setting referred to
earlier. The gure on the next page illustrates the setting options per channel. For more information
about the calibration of the rain gauge and determining the correct Range setting, please refer to
Chapter 7, “Maintenance”.
Operating Instructions
Van Walt Ltd | Prestwick Lane | Grayswood | Haslemere | Surrey | GU27 2DU | Tel. 01428 661 660 | Fax. 01428 656 808 | www.vanwalt.com
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Once the setting options have been entered, all the settings will be programmed into
the datalogger by clicking on the button on the toolbar as shown on the right. The e+
sensor is now ready to be installed. It should be noted that it is not necessary with the e+
sensor to stop the datalogger in advance, as the new settings will be activated as soon
as the datalogger is started again.
3.2 Connection
When the installation of the e+ sensor is a permanent one and the
datalogger is located in an easily accessible place, the IrDa-interface
provides a useful alternative to a permanently installed connecting
cable. The IrDa interface has an optical unit that makes it possible for the
datalogger to be read from a distance of 1...2 metres. It is tted with a 9-pole
sub-D connec- tor for connecting to the COM port of a computer. To read
the datalogger’s data in the eld use should be made of a laptop computer.
When it is not possible to have as datalogger and a computer close
together because the e+sensor is being permanently installed, one
can resort to the use of a DRC readout cable in combination with a
communication cable. A DRC readout cable is available in different lengths
and which is tted with a special connector for connection to a DRC
communication cable. It also has an optical interface for the datalogger.
The DRC communication cable comes in a standard length. It is tted with
connector for connection to the readout cable and has a 9- pole sub-D
connector to connect it to the COM port of a computer.
Operating Instructions
Van Walt Ltd | Prestwick Lane | Grayswood | Haslemere | Surrey | GU27 2DU | Tel. 01428 661 660 | Fax. 01428 656 808 | www.vanwalt.com
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It is common practice in an e-SENSE measuring system for the e+ sensor
to be permanently installed. This requires it to be connected by means of
an e+ sensor e SENSE cable to an e-SENSE SMS modem (eld modem).
An e-SENSE measuring system is designed to carry out remote wireless
transmission of the measurement data from the e+sensors by means of an
SMS modem to a central (Internet) database. This does away with
having to read data in the eld. For further information about e SENSE
measuring systems, the e-SENSE data site or e-SENSE direct and points of
note in connection with the installation, you are referred to the instruction
manual for the e-SENSE SMS modem (eld modem), the e-SENSE data site
and e-SENSE direct. For more information about the types and lengths of
connection cable as well as the IrDa-interface please refer to Chapter 1.1,
“Package contents”.
Operating Instructions
Van Walt Ltd | Prestwick Lane | Grayswood | Haslemere | Surrey | GU27 2DU | Tel. 01428 661 660 | Fax. 01428 656 808 | www.vanwalt.com
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3.3 Installation
Prior to installation it is important to nd a suitable location for the
rain gauge. In the rst instance one should look for a setting where
the measuring cannot be interfered with by obstacles. A useful rule
of thumb is to position the rain gauge at a height that is at least twice
that of nearby obstacles. In the case of special applications it is
possible that there may be other special requirements. Secondly, it is
important for the rain gauge to be placed in a horizontal position. Also
look for a location where the stand for the rain gauge can be placed
in a stable and horizontal position.
Choosing the right measuring location is of great importance as far as obtaining accurate
measuring results is concerned
First of all the stand for the meter must be placed in a
stable and horizontal position. This will require drilling a
hole in the soil in which to place the tube of the stand.
After putting the tube in position place the leftover soil
back into the hole and tamp it down well while holding
the tube in an upright position. Place the xing platform of
the stand on top of the tube and nish by securing it with
socket-head screws.
The rain gauge is now completely disassembled, after
which it is reassembled step by step back on the stand:
1. Place the outer base plate with the three xing holes on
the platform on the stand.
2. Place the inner base plate with the recesses on the outer base plate. The
recesses need to t correctly into the studs while it must be ensured that
the inner base plate cannot be pushed up by the connecting cable.
3. Align both base plates with the aid of the adjustable rings of the stand.
4. Check the horizontal position with a spirit level that is xed to the inner base plate.
5. Secure the outer base plate by screwing the wing nuts on the stud bolts of the stand.
6. Assemble the rain gauge.
Operating Instructions
Van Walt Ltd | Prestwick Lane | Grayswood | Haslemere | Surrey | GU27 2DU | Tel. 01428 661 660 | Fax. 01428 656 808 | www.vanwalt.com
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Communication
cable
Protective cap
(optional)
e+ logger
Mounting nut with
vandalism proof
bolts. Delivered with
measuring station
7. Remove the protective cap (with eye) and the O-ring
of the e+ logger.
8. Remove the nut from the e+ logger. Note that the
support ring and the battery cover are not moved (the
battery housing will not be water tight anymore).
Battery cover
Support ring Nut
Free space Mounting nut
Operating Instructions
Van Walt Ltd | Prestwick Lane | Grayswood | Haslemere | Surrey | GU27 2DU | Tel. 01428 661 660 | Fax. 01428 656 808 | www.vanwalt.com
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10.Re-place the O-ring (that was removed in step 7) in the seat of the
e+ logger
To continue installation for:
• IRDA-readout: step 11 till 14
• Communication cable: step 15 till 18
11.Screw the logger nut on the e+ logger (or use the optional protective cap) and turn it hand
tight. It is also possible to use the protective cap with eye again, however it must be removed
when reading out the logger.
Logger nut Protective cap (optional)
12.Connect the sensor connector to the e+ logger and screw it handtigth with the ring nut.
e+ logger
Ring nut
Sensor connector
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