Rice Lake RL8025 User manual

70998
RL8025
SkirtedTankStructuralSensor
Installation
Guide

Contents
1. Introduction ............................................................................ 1
2. General Installation of the Sensors...................................... 2
3. Sensor Bolt on Instructions .................................................. 4
5. Sensor Wiring......................................................................... 5
4. Insulation ................................................................................ 5
7. Sensor Specifications............................................................. 6
6. Junction Box Connections, Adjustments & Calibration..... 6
8. Limited Warranty ..................................................................... 8
Copyright © 2003 Rice Lake Weighing Systems. All rights reserved.
Printed in the United States of America.
Specifications subject to change without notice.
March 2003

1
1. Introduction
The RL8025 is a bolt-on strain gage load sensor ideal for processing or inventory
control in both indoor and outdoor applications. It is designed to detect changes in
structureandisdesignedspecificallytoworkwithskirtedtankswherelegsareeither
inaccessibleornon-existent.Itisalsocompatiblewithstandardleggedtanksorsilos
andturnsmost anyunit intoa fullweighing apparatusby measuringthe contentsby
either percent or capacity. The RL8025 can create a signal proportional to the load
from the stress detected in the main support members of tanks or silos. That signal
can then be used to interface with standard weighing indicators such as Rice Lake
Weighing Systems’ 920i programmable weight indicator.
Backed with testing results from –40°to 180°F, the RL8025 is used in groups of
six equally spaced units across the body of a skirted tank (as shown in Figure 1 on
page2), or oneach leg ofa structure (asshown in Figure2 on page3). The RL8025
is available in either alloy steel or optional stainless. It should be noted that the
RL8025 sensor can be used on a wide range of capacity vessels, but care needs to
be used when handling them as they are a sensitive device.
The advantages to using the RL8025 include:
•Lowcost. No lifting oftanks or vessels to installload cells under legs,and
less down time while installing the sensors.
•Durable design. Load sensors are off the ground and out of harms way.
Also no risk of damaged sensors caused by falling objects.
•Easybolt-onweighing. Sensorsbolt ontothetank’s legsor skirtedportion
of the silo. You can calibrate to desired units of measurement (level,
percent full or empty).
•Environmentally sealed. Durable design for indoor or outdoor use.
Authorized distributors and their employees can
view or download this manual from the Rice Lake
Weighing Systems distributor site at www.rlws.com.
The installation should be planned by a qualified structural
engineer.Eachinstallationisunique,andthismanualismeant
to serve only as a general guideline for installation.
Caution

2
2. Installation of the Sensors
There are a number of general guidelines that should be taken into consideration
when choosing a sensor mounting location.
•The placement of load sensors on all load bearing support members
ensures that the entire vessel is being weighed.
•Lookforhiddenloadbearingmemberssuchasdischargechutessupported
on the floor and cross connecting structures, such as catwalks, which can
transferloadsfromadjoiningstuctures.Bothcancausesizableerrorsinthe
sensors. Flexible couplings and slip joint couplings can help with these
problems.
•Sixequallyspacedsensorsshouldbeplacedinalocationthatisconvenient
for servicing and on a mounting surface that is flat, free of paint, free of
weldingseams,andawayfromthedangerofforkliftsandtrucks,asshown
in Figure 1.
Figure 1. Sensor Location and a Typical Application Example
•The RL8025 sensors will not work with double walled skirted vessels.

3
Figure 2. Cross Connecting Support Location
•Thesun’s radiantheat hasalarge impacton loadsensorperformance. The
sun heats steel unevenly, producing stresses in the support members. To
minimizetheproblem,mountsensorsonthebacksideoftanklegs/skirtso
they are out of direct sunlight at all times.
•Acorrosiveatomospherearoundthesensorswilleventuallydamagethem.
Consult with your RLWS distributor for possible preventative measures.
•Theloadmustalwaysbeappliedintheprimaryloadaxis.Extraneousloads
or compound stress must be avoided.
•For vertical support members, select a location about halfway up the
support leg or flange when cross connecting supports are present. Mount
the sensors in the middle of the two supports (shown in Figure 2).
H
1/2H 1/2H H
•WhentheRL8025isinterfacedwitha smartindicatorlikethe920i,itisnot
recommended to configure the indicator to show a displayed weight but
instead, to show vessel contents with graphical icons like a bar graph.

4
3. Sensor Bolt-on Instructions
Once you determine where each sensor will be mounted and in which direction the
sensorisoriented,usethefollowingstepstomountthesensortothesidesofthesilo
or vessel as each sensor comes equipped with mounting hardware that will
accomodate a 1/2" thick material.
1. Be sure that the mounting surfaces are clean, dry, and flat to allow maximum
gripping surface area.
2. Using the sensor and the included plastic drill guides as a template, drill two
5/16" holes. (It is normal for the plastic drill guides to spin during the drilling
process.) Remove the drill guides, install bolts and washers as shown below,
and tighten to 25 ft. lbs torque.
Figure 3. Mounting Example
Insert plastic drill
guides into each
hole before drilling
Thermal
compensation
correction. Consult
factory prior to
adjusting
Install one flat and
one star lock washer
on each side of load cell
T
ank leg /
flange

5
5. Sensor Wiring
Each RL8025 comes with a standard 20-foot weather resistant poly cable.
1. Route each sensor cable so they will not be damaged or cut. Cable should
not be routed near heat sources greater than 150°F. Do not shorten any
sensor cable.
2. Attach red (+) and black (–) leads to a power source (either a metered
power supply @ 10 VDC or a 9-volt battery). Attach a digital volt meter
to the green (+) and white (–) leads. If output reads +15 mV or less, the
sensors are ready for use. If output is over +15 mV, loosen the bolts and
retighten,alternatingtheboltstokeeptheoutputbelow+15mV.Continue
until 25 ft. lbs is reached.
3. Connect the sensors to the junction box which should be mounted outside
of the insulation for easy access. Refer to the guide shown on page 6 and
the labels on the the terminal strips of the junction box for correct wiring.
Toverify the wiring scheme, see the certification shipped withthe sensor.
No summing board is necessary.
4. Insulation
All outdoor applications require insulation to obtain the best accuracy level. After
mountingthesensorsoutofdirectsunlight,placeapieceof2'x2'insulationaround
the section of the leg, or attach the 2'x 2' square to the skirt to cover the sensor and
the surrounding area as shown in the following illustration.
Figure 4. Location of Insulation Wrap
2' x 2'
Insulation
patch
Insulation
wrap
2 FT.

6
4. For optimal performance, use positive and negative remote sense lines if
thewiringrunfromthejunctionboxtotheindicatorislongerthan25feet.
6. Adjustments & Calibration
•Refer to the indicator manual for system calibration guidelines.
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7. Sensor Specifications
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Inches
7.19 1.00 .89 1.50 4.79 7.79 1.94 1.25 .50
Millimeters
182.6 25.4 22.6 38.1 121.6 197.8 49.2 31.7 12.7

7
8. Limited Warranty
Rice Lake Weighing Systems (RLWS) warrants that all RLWS equipment and systems
properly installed by a Distributor or Original Equipment Manufacturer (OEM) will operate
perwrittenspecificationsasconfirmed by the Distributor/OEM and accepted by RLWS. All
weighmodulesarewarrantedagainstdefectsinmaterialsandworkmanshipfortwo(2)years.
RLWS warrants that the equipment sold hereunder will conform to the current written
specificationsauthorizedbyRLWS.RLWSwarrantstheequipmentagainstfaultyworkman-
ship and defective materials. If any equipment fails to conform to these warranties, RLWS
will, at its option, repair or replace such goods returned within the warranty period subject
to the following conditions:
• Upon discovery by Buyer of such non-conformity, RLWS will be given prompt
written notice with a detailed explanation of the alleged deficiencies.
•Individual electronic components returned to RLWS for warranty purposes must be
packaged to prevent electrostatic discharge (ESD) damage in shipment. Packaging
requirements are listed in a publication, “Protecting Your Components From Static
Damage in Shipment,” available from RLWS Equipment Return Department.
•Examination of such equipment by RLWS confirms that the non-conformity actually
exists, and was not caused by accident, misuse, neglect, alteration, improper installa
tion, improper repair or improper testing; RLWS shall be the sole judge of all alleged
non-conformities.
•Such equipment has not been modified, altered, or changed by any person other than
RLWS or its duly authorized repair agents.
•RLWS will have a reasonable time to repair or replace the defective equipment.
Buyer is responsible for shipping charges both ways.
•In no event will RLWS be responsible for travel time or on-location repairs, including
assembly or disassembly of equipment, nor will RLWS be liable for the cost of any
repairs made by others.
THESE WARRANTIES EXCLUDE ALL OTHER WARRANTIES, EXPRESSED OR
IMPLIED, INCLUDING WITHOUT LIMITATION WARRANTIES OF MERCHANT-
ABILITY OR FITNESS FOR A PARTICULAR PURPOSE. NEITHER RLWS NOR
DISTRIBUTOR WILL, IN ANY EVENT, BE LIABLE FOR INCIDENTAL OR CONSE-
QUENTIAL DAMAGES.
RLWS AND BUYER AGREE THAT RLWS’S SOLE AND EXCLUSIVE LIABILITY
HEREUNDER IS LIMITED TO REPAIR OR REPLACEMENT OF SUCH GOODS. IN
ACCEPTING THIS WARRANTY, THE BUYER WAIVES ANY AND ALL OTHER
CLAIMS TO WARRANTY.
SHOULD THE SELLER BE OTHER THAN RLWS, THE BUYER AGREES TO LOOK
ONLY TO THE SELLER FOR WARRANTY CLAIMS.
No terms, conditions, understanding, or agreements purporting to modify the terms of this
warranty shall have any legal effect unless made in writing and signed by a corporate officer
of RLWS and the Buyer.
© 2002 Rice Lake Weighing Systems, Inc. Rice Lake, WI USA. All Rights Reserved.
RICE LAKE WEIGHING SYSTEMS • 230 WEST COLEMAN STREET
RICE LAKE, WISCONSIN 54868 • USA