Campbell UT20 User manual

UT20 and UT30 Tower-based
Weather Stations
Revision: 4/12
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REGCOMENDED
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Copyright © 1993-2012
Campbell Scientific, Inc.

Warranty
“PRODUCTS MANUFACTURED BY CAMPBELL SCIENTIFIC, INC. are
warranted by Campbell Scientific, Inc. (“Campbell”) to be free from defects in
materials and workmanship under normal use and service for twelve (12)
months from date of shipment unless otherwise specified in the corresponding
Campbell pricelist or product manual. Products not manufactured, but that are
re-sold by Campbell, are warranted only to the limits extended by the original
manufacturer. Batteries, fine-wire thermocouples, desiccant, and other
consumables have no warranty. Campbell's obligation under this warranty is
limited to repairing or replacing (at Campbell's option) defective products,
which shall be the sole and exclusive remedy under this warranty. The
customer shall assume all costs of removing, reinstalling, and shipping
defective products to Campbell. Campbell will return such products by surface
carrier prepaid within the continental United States of America. To all other
locations, Campbell will return such products best way CIP (Port of Entry)
INCOTERM® 2010, prepaid. This warranty shall not apply to any products
which have been subjected to modification, misuse, neglect, improper service,
accidents of nature, or shipping damage. This warranty is in lieu of all other
warranties, expressed or implied. The warranty for installation services
performed by Campbell such as programming to customer specifications,
electrical connections to products manufactured by Campbell, and product
specific training, is part of Campbell’s product warranty. CAMPBELL
EXPRESSLY DISCLAIMS AND EXCLUDES ANY IMPLIED
WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A
PARTICULAR PURPOSE. Campbell is not liable for any special, indirect,
incidental, and/or consequential damages.”

Assistance
Products may not be returned without prior authorization. The following
contact information is for US and international customers residing in countries
served by Campbell Scientific, Inc. directly. Affiliate companies handle
repairs for customers within their territories. Please visit
www.campbellsci.com to determine which Campbell Scientific company serves
your country.
To obtain a Returned Materials Authorization (RMA), contact CAMPBELL
SCIENTIFIC, INC., phone [phone]. After an applications engineer
determines the nature of the problem, an RMA number will be issued. Please
write this number clearly on the outside of the shipping container. Campbell
Scientific's shipping address is:
CAMPBELL SCIENTIFIC, INC.
RMA#_____
815 West 1800 North
Logan, Utah 84321-1784
For all returns, the customer must fill out a "Statement of Product Cleanliness
and Decontamination" form and comply with the requirements specified in it.
The form is available from our web site at www.campbellsci.com/repair. A
completed form must be either emailed to [e-mail] or faxed to
[phone]. Campbell Scientific is unable to process any returns until we
receive this form. If the form is not received within three days of product
receipt or is incomplete, the product will be returned to the customer at the
customer's expense. Campbell Scientific reserves the right to refuse service on
products that were exposed to contaminants that may cause health or safety
concerns for our employees.

UT20 and UT30 Weather Station
Table of Contents
PDF viewers: These page numbers refer to the printed version of this document. Use the
PDF reader bookmarks tab for links to specific sections.
1. General ......................................................................1-1
1.1 Installation Tasks .................................................................................. 1-1
1.1.1 Indoors ........................................................................................ 1-1
1.1.2 Outdoors...................................................................................... 1-1
1.2 Tools Required ..................................................................................... 1-2
1.2.1 Tools for Tower Installation ....................................................... 1-2
1.2.2 Tools for Instrumentation and Maintenance ............................... 1-2
1.2.3 Supplies for Power and Communications Options ..................... 1-3
1.3 Siting and Exposure.............................................................................. 1-3
1.3.1 Wind Speed and Direction .......................................................... 1-4
1.3.2 Temperature and Relative Humidity........................................... 1-4
1.3.3 Precipitation ................................................................................ 1-4
1.3.4 Solar Radiation............................................................................ 1-5
1.3.5 Soil Temperature......................................................................... 1-5
1.3.6 Siting References ........................................................................ 1-6
1.4 Specifications........................................................................................ 1-6
2. Installation Procedures ............................................2-1
2.1 Tower Installation................................................................................. 2-1
2.1.1 Tower Installation Safety Concerns............................................ 2-1
2.1.2 Base and Guy Anchor Layout..................................................... 2-1
2.1.3 Tower Base Installation .............................................................. 2-2
2.1.3.1 B18 Base Installation ........................................................ 2-2
2.1.3.2 RFM18 Base Installation................................................... 2-4
2.1.4 Guy Anchor Installation.............................................................. 2-4
2.1.4.1 UTEYE Eyebolt Guy Anchor ........................................... 2-4
2.1.4.2 UTDUK Duckbill Guy Anchor ......................................... 2-4
2.1.5 Tower Assembly ......................................................................... 2-6
2.1.6 UTGND Tower Grounding Kit................................................... 2-6
2.2 Sensor Mounting Brackets.................................................................... 2-9
2.2.1 CM202, CM204, CM206, UT018, or UT018-5.......................... 2-9
2.2.2 Gill Radiation Shields ................................................................. 2-9
2.2.2.1 41303-5A, 41003-5 ........................................................... 2-9
2.2.2.2 UT12VA, UT12P, UT6P................................................... 2-9
2.2.3 Solar Radiation Mounts ............................................................ 2-10
2.2.3.1 CM225 Solar Radiation Stand......................................... 2-10
2.2.3.2 UTLI................................................................................ 2-10
3. Instrumentation Installation.....................................3-1
3.1 Enclosure, Datalogger, Power Supply .................................................. 3-1
3.1.1 Enclosure .................................................................................... 3-1
3.1.2 CR1000 Datalogger .................................................................... 3-3
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UT20 and UT30 Weather Station Table of Contents
3.1.3 BPALK Alkaline Power Supply ................................................. 3-3
3.1.4 PS100 Rechargeable Power Supply ............................................ 3-3
3.1.5 SP10 Solar Panel ......................................................................... 3-4
3.2 Sensor Connection ................................................................................ 3-6
3.3 Communication and Data Storage Peripherals...................................... 3-7
3.3.1 CFM100, NL115, or NL120 ....................................................... 3-7
3.3.2 COM220 Phone Modems............................................................ 3-7
3.3.3 Cellular Transceivers................................................................... 3-9
3.3.4 SRM-5A Rad Modem and SC932A Interface............................. 3-9
3.3.4.1 SRM-5A at the Datalogger ................................................ 3-9
3.3.4.2 SRM-5A at the Computer................................................ 3-10
3.3.5 RF500M RF Modem and RF310-Series Transceivers .............. 3-12
3.3.5.1 RF500M Modem Configuration...................................... 3-12
3.3.5.2 RF500M RF Base Station................................................ 3-13
3.3.5.3 Install Nearest Repeater/Field Station ............................. 3-14
3.3.6 MD485 Multidrop Interface ...................................................... 3-14
3.3.6.1 MD485 Multidrop Interface at the Datalogger ................ 3-14
3.3.6.2 MD485 Multidrop Interface at the Computer.................. 3-14
3.4 Sealing and Desiccating the Enclosure ............................................... 3-15
4. Sensor Installation................................................... 4-1
4.1 034B Met One Windset ........................................................................ 4-1
4.2 05103, 05103-45, 05106, and 05305 RM Young Wind Monitors........ 4-2
4.3 03002 RM Young Wind Sentry Wind Set ............................................ 4-3
4.3.1 03002 Mounted to the Mast ........................................................ 4-3
4.3.2 03002 Mounted to CM202, CM204, or CM206 Crossarm ......... 4-3
4.4 Licor Silicon Radiation Sensors (LI200X, LI200S, LI190SB)............. 4-4
4.5 107/108 Temperature Probe.................................................................. 4-5
4.6 107/108 Soil Temperature Probe .......................................................... 4-6
4.7 HMP50 Vaisala Temperature and RH Probe ........................................ 4-7
4.8 HMP45C/HMP35C Vaisala Temperature and RH Probe..................... 4-8
4.9 CS100 or CS106 Vaisala Barometric Pressure Sensor ......................... 4-8
4.10 Texas Electronics Tipping Bucket Rain Gages (TE525, TE525WS,
TE525MM)....................................................................................... 4-9
4.11 TB4, TB4MM, or CS700 Rain Gage .................................................. 4-9
4.12 SR50A Sonic Ranging Sensor .......................................................... 4-10
4.12.1 Beam Angle............................................................................. 4-10
4.12.2 Mounting Height ..................................................................... 4-11
4.12.2.1 Reference Point ............................................................. 4-11
4.12.3 Mounting Options ................................................................... 4-12
4.13 CS616 Water Content Reflectometer................................................ 4-14
4.14 237 Leaf Wetness Sensor.................................................................. 4-15
4.15 257 Soil Moisture Sensor.................................................................. 4-15
4.16 Enclosure Humidity Sensor .............................................................. 4-16
4.17 Wind Direction Sensor Orientation................................................... 4-17
4.17.1 Determining True North and Sensor Orientation .................... 4-17
4.17.2 National Geophysical Data Center Web Site .......................... 4-18
5. Standard Software Installation ............................... 5-1
5.1 Datalogger Program .............................................................................. 5-1
5.2 Weather Station or Datalogger Support Suite....................................... 5-1
5.3 Quick Start Review ............................................................................... 5-1
ii

UT20 and UT30 Weather Station Table of Contents
6. Maintenance and Troubleshooting .........................6-1
6.1 Maintenance.......................................................................................... 6-1
6.1.1 Instrumentation Maintenance...................................................... 6-1
6.1.2 Batteries ...................................................................................... 6-1
6.1.3 Desiccant..................................................................................... 6-2
6.1.4 Sensor Maintenance .................................................................... 6-2
6.2 TroubleShooting ................................................................................... 6-3
6.2.1 No Response Using the Keypad ................................................. 6-3
6.2.2 No Response from Datalogger through SC32B or Modem
Peripheral ................................................................................ 6-3
6.2.3 NaN Displayed in a Variable ...................................................... 6-4
6.2.4 Unreasonable Results Displayed in a Variable ........................... 6-4
Appendix
A. RFM18 Base Dimensions ....................................... A-1
List of Figures
1.3-1. Effect of structure on wind flow....................................................... 1-5
2.1-1. UT30 Tower-Based Weather Station ............................................... 2-2
2.1-2. Top view of base and guy anchor layout.......................................... 2-3
2.1-3. Foundation for B18 base .................................................................. 2-3
2.1-4. B18 concrete mounting base ............................................................ 2-5
2.1-5. RFM18 flat roof mounting base ....................................................... 2-5
2.1-6. UTEYE eyebolt guy anchor ............................................................. 2-5
2.1-7. UTDUK duckbill guy anchor ........................................................... 2-7
2.1-8. Guy wire attached to tower .............................................................. 2-7
2.1-9. Guy wire/turnbuckle attached to UTEYE anchor ............................ 2-8
2.1-10. Ground rod and clamp.................................................................... 2-8
2.1-11. Tower grounding clamp ................................................................. 2-9
2.2-1. Top view of tower .......................................................................... 2-10
2.2-2. CM210 crossarm-to-pole bracket (top) is included with the
crossarm for attaching the crossarm to the tower’s mast or leg...... 2-11
2.2-3. UT12VA Gill Radiation Shield and UT018 Crossarm................... 2-11
2.2-4. UTLI Leveling Fixture/Crossarm Mount and UT018 .................... 2-12
2.2-5. CM225 Solar Radiation Mount with a LI2003S Leveling Base
and LI200X Solar Radiation Sensor ......................................... 2-12
3.1-1. Enclosure brackets configured for a tower mount............................ 3-2
3.1-2. This exploded view shows the components of a “-TM” bracket
option .......................................................................................... 3-2
3.1-3. An enclosure attached to two tower legs.......................................... 3-3
3.1-4. BPALK 12 volt power supply .......................................................... 3-4
3.1-5. CR1000 and PS100 mounted to an enclosure backplate .................. 3-5
3.1-6. SP10 solar panel ............................................................................... 3-6
3.2-1. Routing and wiring sensor leads to the datalogger........................... 3-7
3.3-1. The NL115 connects to the CR1000’s peripheral port allowing
data to be stored on removable Compact Flash cards................. 3-8
3.3-2. COM220 modem with surge protector............................................. 3-8
3.3-3. SRM-5A Rad Modem and SC932A Interface................................ 3-10
3.3-4. SRM-5A wiring.............................................................................. 3-11
iii

UT20 and UT30 Weather Station Table of Contents
iv
3.3-5. You can configure any two types of interface ports (RS-485,
RS-232, and CS I/O) to be used at a time ................................. 3-15
3.4-1. Enclosure Supply Kit...................................................................... 3-16
4.1-1. Met One 034B Wind Speed and Direction Sensor ........................... 4-1
4.2-1. 05103 RM Young Wind Monitor ..................................................... 4-2
4.3-1. 03002 mounted to a CM200-series Crossarm................................... 4-3
4.4-1. LI200X/LI200S/LI190SB and LI2003S Leveling Fixture ............... 4-4
4.5-1. 107 Temperature Probe .................................................................... 4-5
4.7-1. HMP50 Temperature and RH Probe................................................. 4-7
4.8-1. HMP45C Vaisala Temperature and RH Probe ................................. 4-8
4.10-1. TE525 Texas Electronics Rain Gage.............................................. 4-9
4.11-1. TB4 or TB4MM mounted onto a CM310 pole via the
CM240 mount ........................................................................... 4-10
4.12-1. Beam angle clearance ................................................................... 4-11
4.12-2. Distance from edge of transducer housing to grill........................ 4-12
4.12-3. SR50A mounted to a crossarm via the 19517 Mounting Kit........ 4-12
4.12-4. The SR50A mounted to the crossarm shown from another
angle.......................................................................................... 4-13
4.12-5. SR50A - mounted using NU-RAIL and C2151 mounting stem...4-13
4.13-1. CS616 Water Content Reflectometer with #14383 Probe
Insertion Guide.......................................................................... 4-14
4.14-1. 237 Leaf Wetness Sensor ............................................................. 4-15
4.15-1. 257 Soil Moisture Sensor ............................................................. 4-16
4.16-1. CS210 installed on a CR1000....................................................... 4-16
4.17-1. Magnetic declination for the contiguous United States ................ 4-18
4.17-2. Declination angles east of True North are subtracted from
0 to get True North.................................................................... 4-18
4.17-3. Declination angles west of True North are added to 0 to
get True North........................................................................... 4-19

Section 1. General
This section provides preparation and siting information as well as specifications.
1.1 Installation Tasks
1.1.1 Indoors
•Immediately upon receipt of your shipment…
⇒Open shipping cartons.
⇒Check contents against invoice. Contact CSI immediately about any
shortages.
•Several days prior to the planned installation date…
⇒Collect tools and site information (Section 1)
⇒Assemble datalogger, communications device, and power supply in
enclosure (Section 3)
⇒Install datalogger support software on PC (Section 5)
⇒Establish communications between the datalogger and the PC
(Section 5)
⇒Program datalogger, test sensors, and retrieve data (Section 5)
⇒Trial run the tower / tripod installation, assembling as much as
possible (Section 2)
⇒Repackage equipment for transport to the field site
1.1.2 Outdoors
•Locate suitable site (Section 1)
•Prepare tower base (Section 2)
⇒Install 3 to 10 meter level sensors (Section 4)
⇒Raise tower (Section 2)
⇒Install instrumentation enclosure (Section 3)
⇒Install 0 to 3 meter level sensors (Section 4)
1-1

Section 1. General
1.2 Tools Required
Tools required to install and maintain a weather station are listed below.
1.2.1 Tools for Tower Installation
Shovel
Rake
Open end wrenches: 3/8", 7/16", ½", (2) 9/16"
Magnetic compass
6' Step ladder
Tape measure (12' and 20')
Nut driver (3/8")
Level (36" to 48")
Small sledge hammer
Pliers
Tie wire
Climbing harness
Hard hat
Haul rope (50')
Non-stretch line (20')
Wire rope cutters
Materials for B18 Base and UTEYE Anchors:
(4) Wood stakes 12"
Pick or digging bar
Concrete form materials (2"x 4" lumber, stakes, saw, hammer, nails, etc.)
Concrete trowel and edger
Materials for UTDUK Duckbill Anchors
Sledgehammer
Highlift jack
Chain (to attach jack to anchor loops)
Materials for RFM18 Base:
(4) anchors appropriate for mounting surface
(4) bolts and washers to secure base to anchors
1.2.2 Tools for Instrumentation and Maintenance
Lock and key for enclosure
Magnetic declination angle (Section 4)
Magnetic compass
Straight bit screwdrivers (small, medium, large)
Phillips-head screwdrivers (small, medium)
Small diagonal side-cuts
Needle-nose pliers
Wire strippers
Pocket knife
Calculator
Volt / Ohm Meter
Electrical Tape
Step ladder (6')
Datalogger prompt sheet (Section 6)
Station manuals
Station log and pen
Open end wrenches: 3/8", 7/16", ½", (2) 9/16"
1-2

Section 1. General
Socket wrench and 7/16" deep well socket
Adjustable wrench
Pliers
Conduit and associated tools (as required)
Felt-tipped marking pen
Claw hammer
Pipe wrench (12")
Tape measure (12' to 20')
3/8" nut driver
Level (36" to 48")
Pliers
Climbing harness
Hard hats
50' haul rope
Crescent wrench
Channel-lock pliers
¼" washers (spacers for U-bolts)
5/64" Allen hex wrench
1.2.3 Supplies for Power and Communications Options
AC Power
Wire, conduit, and junction boxes as needed
Phone Modem
Hayes compatible calling modem for PC
Phone line to weather station or junction box
Short-Haul Modem
4 Conductor communications cable from PC to weather station or junction box
6' copper ground rod and clamp for PC surge protection (optional)
1.3 Siting and Exposure
If any part of the weather station comes in contact with
power lines, you could be killed. Contact local utilities for
the location of buried utility lines before digging or driving
ground rods.
CAUTION
Selecting an appropriate site for the weather station is critical in order to obtain
accurate meteorological data. In general, the site should be representative of
the general area of interest, and away from the influence of obstructions such
as buildings and trees.
The weather station should not be located where sprinkler irrigation water will
strike sensors or instrument enclosure.
Some general guidelines for site selection are listed below, which were
condensed from EPA (1988)1, WMO (1983)2, and AASC (1985)3publications.
1-3

Section 1. General
1.3.1 Wind Speed and Direction
Wind sensors should be located over open level terrain, and at a distance of at
least ten times (EPA) the height of any nearby building, tree or other
obstruction, as illustrated in Figure 1.3-1.
Standard measurement heights:
3.0 m ± 0.1 m recommended (AASC)
2.0 m ± 0.1 m, 10.0 m ± 0.5 m optional (AASC)
10.0 m (WMO and EPA)
1.3.2 Temperature and Relative Humidity
Sensors should be located over an open level area at least 9 m (EPA) in
diameter. The surface should be covered by short grass, or where grass does
not grow, the natural earth surface. Sensors should be located at a distance of
at least four times the height of any nearby obstruction and at least 30 m (EPA)
from large paved areas. Sensors should be protected from thermal radiation,
and adequately ventilated.
Situations to avoid include:
•large industrial heat sources
•rooftops
•steep slopes
•sheltered hollows
•high vegetation
•shaded areas
•swamps
•areas where snow drifts occur
•low places holding standing water after rains
Standard measurement heights:
1.5 m ± 1.0 m (AASC)
1.25 - 2.0 m (WMO)
2.0 m temperature (EPA)
2.0 m and 10.0 m for temperature difference (EPA)
1.3.3 Precipitation
A rain gage should be sited on level ground that is covered with short grass or
gravel. In open areas, the distance to obstructions should be two to four times
(EPA, AASC) the height of the obstruction.
The height of the opening should be as low as possible, but should be high
enough to avoid splashing from the ground. Wind shields, such as those used
by the National Weather Service, are recommended for open areas.
1-4

Section 1. General
Collectors should be heated, if necessary, to properly measure frozen
precipitation. The gage must be mounted above the average level of snow
accumulation in areas that experience significant snowfall.
Standard measurement heights:
1.0 m ± 1.0 cm (AASC)
30.0 cm minimum (WMO, EPA)
1.3.4 Solar Radiation
Pyranometers should be located to avoid shadows on the sensor at any time.
Mounting it on the southern most (northern hemisphere) portion of the weather
station will minimize the chance of shading from other weather station
structures. Reflective surfaces and sources of artificial radiation should be
avoided. The height at which the sensor is mounted is not critical.
1.3.5 Soil Temperature
The measurement site for soil temperature should be at least 1 m2and typical of
the surface of interest. The ground surface should be level with respect to the
immediate area (10 m radius).
Standard measurement depths:
10.0 cm ± 1.0 cm (AASC)
5.0 cm, 10.0 cm, 50.0 cm, 100.0 cm (WMO)
FIGURE 1.3-1. Effect of structure on wind flow
1-5

Section 1. General
1.3.6 Siting References
1EPA, (1987). On-Site Meteorological Program Guidance for Regulatory
Modeling Applications, EPA-450/4-87-013. Office of Air Quality Planning
and Standards, Research Triangle Park, North Carolina 27711.
2WMO, (1983). Guide to Meteorological Instruments and Methods of
Observation. World Meteorological Organization No. 8, 5th edition, Geneva,
Switzerland.
3The State Climatologist, (1985) Publication of the American Association of
State Climatologists: Height and Exposure Standards for Sensors on
Automated Weather Stations, v. 9, No. 4 October, 1985.
4EPA, (1989). Quality Assurance Handbook for Air Pollution Measurement
Systems, EPA Office of Research and Development, Research Triangle Park,
North Carolina 27711.
1.4 Specifications
UT20 Measurement Height: 20 ft (6 m)
UT30 Measurement Height: 30 ft (10 m)
UT20 Shipping Weight: 50 lbs (23 kg)
UT30 Shipping Weight: 65 lbs (29 kg)
Material: hardened drawn 6063-T832 aluminum
Vertical Pipe Outer Diameter: 1 in. (2.5 cm)
Cross Support Pipe Outer
Diameter: 0.375 in. (0.953 cm)
UT20 Guyed Tower Area
Requirements: ~11.5 ft radius
UT30 Guyed Tower Area
Requirements: ~17 ft radius
Required Concrete Pad
Dimensions forB18 Concrete
Mounting Base (see note 1): 36 L x 36 W x 48 D in.
(91 x 91 x 122 cm)
Maximum Wind Load
Recommendations (see note 2): 110 mph (B18 base unguyed);
110 mph (RFM18 base w/UTGUY)
Notes:
1. The concrete pad requirements assume heavy soil; light, shifting, or sandy
soils require a bigger concrete pad.
1-6

Section 1. General
2. The recommended wind load assumes proper installation, proper
anchoring, and total instrument projected area of less than two square
feet. For the RFM18 base, the wind load recommendation also assumes
that the UTGUY’s turnbuckles are preloaded just enough to equalize
tension and that the tower is guyed at 60 degree angle relative to the
ground (maximum). The amount of wind load that these towers can
withstand is affected by quality of anchoring and installation, guy wire
tension, soil type, guy angle, and the number, type, and location of
instruments fastened to the tower.
3. The UT30 is Universal Towers’ model #9-30. A more detailed drawing of
this tower is available at www.universaltowers.com.
1-7

Section 1. General
1-8

Section 2. Installation Procedures
2.1 Tower Installation
The UT20 20-ft tower and UT30 30-ft tower provide a support structure for
mounting the weather station components. Figure 2.1-1 shows a typical UT30
equipped with instrumentation enclosure, meteorological sensors, and solar
panel.
2.1.1 Tower Installation Safety Concerns
Tower installation near power lines is dangerous. The
minimum safe recommended distance from overhead
power lines is two times the height of the tower and
mast combined.
WARNING
When installing the tower, remember:
•DO NOT use a metal ladder
•DO NOT work on a wet or windy day
•DO dress properly−shoes with rubber soles and heels, rubber gloves, and
long sleeves.
2.1.2 Base and Guy Anchor Layout
1. A guyed UT20 tower requires an area approximately 11.5 ft in radius, and a
guyed UT30 tower requires an area approximately 17 feet in radius. Brush
and tall weeds should be removed, otherwise the natural vegetation and
ground surface should be disturbed as little as possible.
2. Drive a stake where the base of the tower will be located. Attach a line to
the stake and scribe a circle with an 11.5 ft radius for the UT20 or a 17 ft
radius for the UT30. Drive a stake on the scribed line opposite the
direction the tower will hinge for the first guy anchor location (Figure
2.1-2).
When using a UT30 on level ground, lay out the remaining two anchor
locations by measuring 29.5 ft from the first anchor to the scribed line on
either side of the base stake (Figure 2.1-2). When using a UT20 on level
ground, lay out the two remaining anchor locations 10 ft from the first
anchor to the scribed line on either side of the base stake.
On unlevel ground, use a compass at the base stake to lay out the
remaining two anchor locations 120 degrees from the first. Vary the
distance between the tower and each anchor so that the angle between the
tower and the guy wire will be approximately 30 degrees.
2-1

Section 2. Installation Procedures
2.1.3 Tower Base Installation
There are two base options: the B18 base is poured in concrete; the RFM18
roof mount base is anchored to a flat surface.
2.1.3.1 B18 Base Installation
1. Dig a hole 36" square and 48" deep where the tower base will be located
(Figure 2.1-3).
2. Optional⎯construct a concrete form out of 2" x 4" lumber 36" square
(inside dimensions). Center the form over the hole and drive two stakes
along the outside edge of each side. Level the form by driving nails
through the stakes and into the form while holding the form level.
3. Attach the bottom section of the tower to the B18 base using one bolt per
leg, making sure that the hinge direction is common for all legs.
4. Center the bottom tower section with the base attached in the hole. Orient
the tower/base for the proper hinge direction. Make sure that the top of
the legs will be at least 1/2" above the finished height of the concrete
(Figure 2.1-4).
5. Fill the hole with concrete. Getting the bottom tower section plumb is
very important. As concrete is poured into the hole, periodically check the
tower for plumb using a carpenter's level and make adjustments as
necessary. Allow three to four days for the concrete to cure.
REGCOMENDED
FeedSENSORS
PortlandOrUSA
Serial27115
REGCOMENDED
FeedSENSORS
PortlandOrUSA
Serial27115
REGCOMENDED
FeedSENSORS
PortlandOrUSA
Serial2711527115
FIGURE 2.1-1. UT30 Tower-Based Weather Station
2-2

Section 2. Installation Procedures
120
29.5 '
17 ' RADIUS
TILT DIRECTION
(NORTH)
CENTER POINT
ANCHOR LOCATIONS
(3) PLCS
29.5 '
FIGURE 2.1-2. Top view of base and guy anchor layout
SIDE VIEW
TOP VIEW
ANCHOR BOLT
CEMENT
FOUNDATION
48"
36"
36"
North
B18 Leg #2
B18 Leg #3
B18 Base Legs
(3) places
B18
Leg #1
Cement
Foundation
FIGURE 2.1-3. Foundation for B18 base
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Section 2. Installation Procedures
2.1.3.2 RFM18 Base Installation
1. Position the RFM18 on the surface where it will be installed. Make sure
the hinge direction is correct and mark the locations of the four mounting
holes. A drawing showing RFM18 dimensions and hole spacing is shown
in Appendix A. Install an appropriate anchor (user-supplied) for each
hole.
Attach the bottom section of the tower to the RFM18 base using one bolt
per leg (Figure 2.1-5). Position the base over the anchor holes. Secure the
base to the anchors with appropriate hardware (user-supplied). Check the
tower for plumb and shim the RFM18 if necessary before fully tightening
the bolts.
2.1.4 Guy Anchor Installation
There are two types of anchors for the tower guy wires: the UTEYE eye bolts
are poured in concrete; the UTDUK duckbill anchors are driven into the soil.
2.1.4.1 UTEYE Eyebolt Guy Anchor
1. Dig a hole 24" square by 24" deep at each anchor location (Section 2.1.2).
2. Optional⎯construct a concrete form out of 2" x 4" lumber 24" square
(inside dimensions) for each hole. Center the forms over the holes and
level them using a carpenter's level and stakes.
3. Fill the holes with concrete and install the eyebolts as shown in Figure
2.1-6.
2.1.4.2 UTDUK Duckbill Guy Anchor
1. Locate the three anchor locations (Section 2.1.2). It is important that the
anchors be driven at the same angle as the guy wires (Figure 2.1-7). Insert
the steel drive bar into the anchor body and drive the anchor into the
ground using a fence post driver or sledgehammer until only the top half
of the loop remains above the ground.
2. Attach a high-lift jack to the loop and jack the anchor up about 6 inches to
rotate the anchor into the load-lock position.
Failure to install and lock the anchor at the correct
angle will result in the anchor cable cutting through
the soil until the angles equalize, causing slack in the
guy wires.
WARNING
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