Casella CEL Automatic weather station User Manual

Automatic Weather Station
Assembly & Commissioning Handbook

Automatic Weather Station

Assembly & Commissioning

October 2002

Handbook

HB3303-01

Weather stations are frequently supplied as customised solutions, each
having its own unique configuration and calibration details. For system

specific information, please refer to the “Calibration and System Details”

section at the rear of this handbook.

COPYRIGHT

The copyright in this document which contains proprietary information is vested in

CASELLA CEL. The contents of this document must not be used for

purposes other than for which it has been supplied or reproduced or disclosed wholly

or in part without the prior written permission of

CASELLA CEL

CASELLA CEL
Regent House
Wolseley Road
Kempston
Bedford
MK42 7JY U.K.
Phone: [phone]
Fax: [phone]
E-Mail: [e-mail]
Web: www.casellacel.com

CASELLA USA
17 Old Nashua Road #15
Amherst
NH 03031
U.S.A.
Toll Free: [phone]
Fax: [phone]
E-mail: [e-mail]
Web: www.casellausa.com

Contents

Automatic Weather Station

Assembly & Commissioning Handbook

Page 2 of 34

Automatic Weather Station
Assembly & Commissioning Handbook

Contents . . . . . . . . . . . . . . . . . . . . Page

Section 1: General Information . . . . . . . . . . . 5

1. INTRODUCTION TO THE AUTOMATIC WEATHER STATION .... 7

1.1 Features . . ................ 7

1.2 Applications . . ................ 7

2. ASSEMBLY & COMMISSIONING . ................ 9

2.1 Transporting The System ............... 9

2.2 Siting . . ................ 9

2.3 System Enclosure . . ................10

2.3.1 Frame Mounted Systems . . ..........10

2.3.2 Wall Mounting . ................10

2.4 Lighting Protection . . ................10

2.5 Fitting & Deploying Sensors ..............11

2.6 Wiring . . ................12

2.6.1 System Wiring . ................12

2.6.2 Sensor Wiring . ................12

2.6.3 Wire Preparation and Insertion .........13

2.7 System Power Supply . ................14

2.7.1 Solar Power Installations . . ..........14

2.7.2 Direct Landline Connected Systems . . . ....14

2.7.3 Mains Power Option ..............15

2.7.4 Replacement Battery Option ..........15

2.7.5 Conserving Battery Power . ..........16

2.8 UHF / VHF Radio Telemetry Option . ..........16

2.9 Activiating Remote Weather Stations ..........17

2.10 Switching On . . ................17

3. SENSORS USED WITH AUTOMATIC WEATHER STATIONS ....19

3.1 Combined Air Temperature and Relative Humidity Sensor 19

3.1.1 Temperature Sensor Specification ........19

3.1.2 Humidity Sensor Specification .........20

3.1.3 Air Temperature & Humidity -

Sensus Channel Configurations ....20

3.2 WindSpeedSensor ..................20

3.2.1 Wind Speed Sensor Specification ........20

3.2.2 Wind Speed Sensor -

Sensus Channel Configuration ....21

3.3 Wind Direction Sensor . ................21

3.3.1 Wind Direction Sensor Specification . . . ....21

3.3.2 Wind Direction Sensor -

Sensus Channel Configuration ....22

3.4 Global Solar Radiation Sensor . . . ..........22

3.4.1 Global Solar Radiation Sensor Specification . . . 22

3.4.2 Solarimeter - Sensus Channel Configuration . . . 23

3.4.3 Sunshine Duration ...............23

3.5 Standard Barometric Pressure Sensor ..........23

3.5.1 Standard Barometric Pressure Sensor

Specification . . . ..........23

3.5.2 Barometer - Sensus Channel Configuration . . . 24

3.6 Precision Barometer . . ................24

3.6.1 Precision Barometer Specification ........24

Contents

Page 3 of 34

Contents

Assembly & Commissioning Handbook

Automatic Weather Station

Contents . . . . . . . . . . . . . . . . . . . . Page

3.6.2 Precision Barometer -

Sensus Channel Configuration ....24

3.7 Rainfall Sensor . . ................25

3.7.1 Rainfall Sensor Specification ..........25

3.7.2 Tipping Bucket - Sensus Channel Configuration . 25

3.8 Soil Temperature Sensor ................26

3.8.1 Soil Temperature Sensor Specification . . ....26

3.8.2 Soil Temperature Sensor -

Sensus Channel Configuration ....26

3.9 Leaf Wetness Sensor . . ................26

3.9.1 Leaf Wetness Sensor Specification . . . ....27

3.9.2 Leaf Wetness Sensor -

Sensus Channel Configuration ....27

3.10 Grass Temperature Sensor ...............27

3.10.1 Grass Temperature Sensor Specification . ....27

3.10.2 Grass Temperature Sensor -

Sensus Channel Configuration ....28

3.11 Additional Gas Sensors . ................28

4. ROUTINECARE ........................29

5. SERVICING & WARRANTY . . . ................31

Section 2: Calibration & System Details . . . . . . 33

Page 4 of 34

Automatic Weather Station
Assembly & Commissioning Handbook

Section 1: General Information

Page 5 of 34

Automatic Weather Station

Assembly & Commissioning Handbook

Page 6 of 34

Automatic Weather Station
Assembly & Commissioning Handbook

Introduction

1. INTRODUCTION TO THE AUTOMATIC
WEATHER STATION

The Casella CEL Automatic Weather Station is designed to satisfy a wide range
of professional meteorological monitoring applications.

It is of a flexible design, permitting many different communication,

sensor, power supply and software options.

1.1 Features

¤ Rugged construction for long term or permanent deployment
¤ High quality components
¤ Latest logging technology records approximately 15 k data sets as

standard

¤ Compact Flash Expansion Slot for prolonged monitoring applications
¤ Optional solar-panel/charger allows extended operation
¤ Pre-configured 32-bit Online Pro PC software, for real-time and

historic data analysis

¤ Telemetry options include: RS232, RS485, low power radio, PSTN

modem, or global access using GSM modem

1.2 Applications

¤ Environmental consultancy
¤ Site boundaries
¤ Landfill sites
¤ Emergency services
¤ Military operations
¤ Conditions at ports and harbours
¤ Airports gliding clubs
¤ Agrochemical field trials
¤ Fruit growing
¤ Hydrological studies
¤ Schools & colleges for field studies
¤ Geotechnical studies
¤ Golf courses
¤ Athletics meetings

Page 7 of 34

Introduction

Automatic Weather Station

Assembly & Commissioning Handbook

Page 8 of 34

Automatic Weather Station
Assembly & Commissioning Handbook

Commissioning

2. ASSEMBLY & COMMISSIONING

All Casella CEL Automatic Weather Stations are fully assembled and tested as an
integral system prior disassembly and to dispatch from the factory.

WARNING !

Before attempting to assemble and commission this CASELLA

CEL Automatic Weather Station, please carefully study the

installation procedures and drawings provided in this

handbook. For specialised systems, supplementary assembly

notes are also provided at the back of this book.

Contact your supplier immediately, should any parts be missing or

damaged.

2.1 Transporting The System

WARNING !

Neither the small (landline backup) nor the large (solar

battery) are secured in their respective enclosures.

ALWAYS DISCONNECT AND REMOVE the batteries to prevent

electrical and physical damage when transporting the system.

The solar battery is not sealed and must remain in an upright

position to prevent acid spillage.

2.2 Siting

The measurements used in meteorology are intended to represent general
conditions over as large an area around the measuring point as possible.

To achieve the most representative of local conditions, the weather

station should be sited in an unobstructed area open to the sun and wind. This
also maximises the efficiency of any solar-panel power supply when fitted. Sites
sheltered by trees or buildings, in hollows or on the sides of hills are not
recommended, neither are sites on buildings, as none of these locations will give
truly representative surface measurements.

The Automatic Weather Station is designed to meet these conditions.

Typically, it’s sensors should be mounted on a cross-bar located at least 2.0 m
above the ground, for example on the support frame, on a properly designed
base or on some other structure. The data acquisition unit enclosure, which also
houses control and communication systems may be mounted on the frame, or
on a suitable nearby building or structure.

A suitable concrete base to support the frame would be 1.5 metres

square and approximately 20 to 30 cm thick. When installing on a tower or
building, the fixing technique used must also pay consideration to the material
type, building structure and material thickness available at the installation site.

For systems utilising solar power, the orientation of the frame is

important. In the northern hemisphere the rear of the main enclosure must face
south while in the southern hemisphere it must face north. This allows the solar
panel to be aligned to face the mean position of the sun in its daily and yearly
path. (Please refer to the “Power Supplies” section for further details).

The U.K. Meteorological Office (Met Office) recommends that the

instruments be installed over closely mown grass. For further guidance, refer to
the Met Office leaflets:

Page 9 of 34

Assembly & Commissioning

Assembly & Commissioning Handbook

Making weather observations,
Manual weather measurements,
Automatic weather measurements,
Voluntary observations network.

Automatic Weather Station

2.3 System Enclosure

The heart of the weather station system is the Sensus 24 channel data logger.
This data acquisition unit plus any additional electronic hardware are housed
within a protective IP68 enclosure that is designed to be wall or frame mounted.

2.3.1 Frame Mounted Systems

For frame mounted applications, please refer to the Frame Assembly Drawing
included. In the majority of applications, M8 rawl bolts may be used to secure
the frame (M8 rawl bolts require a 14 mm diameter mounting hole).

Ensure that correct size fasteners are used throughout the

assembly, as indicated on the assembly drawing.

1. Commence frame assembly with the two upright sections laying down.

The base end of the two upright sections can be identified by the larger
drilled holes.

2. Fasten the data acquisition enclosure to the frame, using the bolts and
washers shown in the drawing.

3. Securely mount the frame assembly by its four feet to a solid surface.

The frame should be mounted vertically and level.

Refer to Section 2.1 for advice on mounting and orientation for solar
panels.

2.3.2 Wall Mounting

The data acquisition enclosure is fitted with brackets which allow quick and safe
attachment to a suitable wall. The brackets may be secured to the wall using
M8 x 25 mm stud type rawl bolts.

Mark the hole positions by spotting through the mounting holes whilst

the unit is held in the desired position. The required hole size for the rawl bolts
is 14 mm diameter and 60 mm deep.

2.4 Lightning Protection

WARNING !

Lightning protection must be installed as directed in the

following procedure.

If the procedure is not followed completely the integrity of the

lightning protection circuit may be compromised which could

result in damage or destruction of the weather station system.

Note that the basic lightning protection system provided may

require upgrading in situations where soil and surface

conductivity is poor.

The Frame Assembly Drawing indicates the position of the lightning protection
items.

Page 10 of 34

Automatic Weather Station
Assembly & Commissioning Handbook

1. Take the smaller diameter AIR TERMINAL ROD and screw it into the
threaded hole in the centre of the top cross arm.

DO NOT REMOVE THE NUT FROM THE AIR TERMINAL ROD.

Once the ROD has been threaded fully into the hole tighten the nut
down on to the cross arm.

2. Next take the TEST CLAMP and secure it to a hole at the bottom of
either of the frame uprights, flat side towards the frame.

Thread the bolt through the frame into the TEST CLAMP and tighten.

3. Loosen the bolt on the outside of the TEST CLAMP sufficiently to allow
the flat DOWN CONDUCTOR to be inserted into the TEST CLAMP.
Having inserted the DOWN CONDUCTOR, secure it to the TEST CLAMP
by tightening the bolt, ensuring that the bolt presses on to the bare
surface of the DOWN CONDUCTOR.

4. Remove the FIXING CLAMP from the EARTH ROD at the free end of the
DOWN CONDUCTOR.

Then drive the EARTH ROD into the ground.

Assembly & Commissioning

The EARTH ROD should be driven in until approximately 15 cm of the
rod is protruding from the surface.

5. Replace the FIXING CLAMP over the end of the EARTH ROD and DOWN
CONDUCTOR and clamp the two together by tightening the clamp bolt.

Ensure that the EARTH ROD is located in the vee of the FIXING CLAMP
and the DOWN CONDUCTOR lies against the inner flat surface under
the clamp bolt.

2.5 Fitting & Deploying Sensors

The sensor locations depend upon the specific installation arrangement and site
details. The sensors may be physically attached to the weather station frame or
can be remotely mounted on a supporting structure such as a tower or tall
building. Refer to Section 2.2 Siting and to the automatic weather station
Assembly Drawings to understand typical sensor locations.

Rain Gauge

Deploy the rain gauge at least 4 m from the frame. Level the tipping bucket
using its integral spirit level. Secure the bucket to a concrete base or paving slab
using M8 Rawl bolts.

Carefully remove any restriction, such as an elastic band that may

have been fitted to prevent the bucket from moving during transit, and check
that the bucket pivots freely.

Wind Direction Sensors

Align the wind direction sensor so that the two dots located on the base of the
sensor or the “N” label face North. Generally, wind measuring sensors should be
located on the top cross arm of the weather station frame.

All wiring from the sensors should be routed tidily to the enclosure

following the desired route. The cables in most installations are protected by
plastic coated steel conduit. Secure the cables and conduit to any structures
using suitable cable ties. Avoid putting any cables under stress or in locations
where damage is likely to occur.

Passing cables through conduit may be made easier by using an

electricians “wiring mouse”.

Page 11 of 34