weigh-in-motion strip scale application guide strip scale applications.pdf · weigh-in-motion strip...

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Accurate & Reliable In-Ground WIM SystemsWeigh-in-Motion Strip Scale Application Guide

Visit us online at intercompcompany.com or call us at +1 763-476-2531 Worldwide


W I M S t r i p S c a l e A p p l i c a t i o n G u i d e

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Strain gauge technology is widely accepted as the most accurate and reliable means to weigh a vehicle. Unlike other WIM sensors, Intercomp’s strip scales integrate strain gauge technology in a compact strip for accurate WIM applications. These sensors are capable of meeting or exceeding ASTM E1318-09 Type I, Type II, Type III and COST 323 A(5), B+(7), or B(10) performance requirements. Installed within 3˝ wide (75mm) channels cut into either asphalt or concrete, the scale delivers higher performance at a lower cost, with minimal time and labor associated with installation and maintenance.

Weigh-in-Motion Strip Scales Patent pending

Strip scale solutions provide accurate dynamic weighing, while temperature compensation ensures proven consistency even in harsh environments. The performance, reliability and longevity of Intercomp’s WIM systems provide the best return on investment of any form of WIM technology. Strip scales involve minimally invasive installation in the mainline, and can be paired with Intercomp scales in off ramps and static or portable weighing applications.

WIM Strip Scales can be configured in sets of 1, 2 or 3 pairs depending on the application and required accuracy. When combined with cameras, detectors and data transmission devices, they are capable of serving as stand-alone virtual remote weigh stations. They can also be configured to work in tandem with commercial weigh stations as a screening device enabling enforcement to focus efforts on the most probable offenders.

In-Ground Strip Scales for WIM

WIM screening allows transportation engineers to study traffic

characteristics for the planning and maintenance of roadways.

Data Collection

Vehicle data such as classification and flagged violations can be

remotely accessed for enforcement efforts downstream of WIM site.

Screening for Enforcement

Traffic can be directed to specific lanes, off the mainline for

further inspection, or to continue on without further interruption.

Pre-Selection

Data collection to identify and divert overloaded vehicles for protecting

bridges and infrastructure.

Bridge Protection

Weight based information is used to confirm vehicle loading or calculate

fees. In tolling, heavier vehicles are charged more than lighter vehicles

due to impact on roadways.

Tolling/Ports of Entry

Meets or Exceeds ASTM E1318-09 Type I, II, III and COST 323 A(5), B+(7) or B(10) Performance Requirements

Strip Scales

Intercomp strip scale WIM systems are designed to deliver best-in-class accuracy across a wide range of speeds and temperatures.

ACCURACY

Flexibility—In Integration from Sensor Replacement to Full Systems

Maintenance—Can be Ground Flushwith Changing Road Conditions

Accurate— Across Variety of Speeds & Temperature Extremes

Durability—Field Proven Through Millions of Cycles

Installation—In a Single Day with Minimal Traffic Interruptions

Variable Sizes— Sensor comes in 59˝, 69˝, 79˝ (1.5, 1.75, 2m) Lengths




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Customizable systems ranging from data gathering and screening to full V-WIM systems, with software modified to particular output requirements, including classification and violation codes. One can integrate a variety of hardware and components based on specific application and site needs.

Virtual-WIM Virtual Weigh-In-Motion or V-WIM systems are an unattended, unmanned means of automatically collecting data. V-WIM integrates the load-cell based scale technology with cameras utilizing optical character recognition, license plate reader technology, and wireless output. This allows collection of a variety of traffic data, such as GVW, axle weight, vehicle class, ID and imaging; all of which can be accessed from a remote location via the web.

1. Strip Scales Only with Analog Output

The scales are shipped with cables attached. The customer provides Data Acquisition with Signal Conditioning, and all processing.

WIMLOGIX Series Specifications

• Up to 8 Scale Inputs & 2 Loop Inputs • Output Consistent with FHWA Traffic Management Guide (TMG) Standards, or can be Modified to Requirements • Rack Mounted in Cabinet • Ethernet Jacks for Connection to Electronics • IEC Power Connection with Slot for Fuse (1A). Power LED Indicator, 100-240VAC Input. DC Power Available • Operating Temperature: -13 to 131˚F (-25 to 55˚C)

2. Strip Scales with WIMLOGIX CPU Module & Ethernet Output

The strip scales and loop detector connect to the WIMLOGIX module, which provides signal conditioning, data acquisition, and basic processing. Intercomp can supply a Windows-based API for software development, or the raw serial protocol for other integration plans. These options connect and control the WIMLOGIX module via Ethernet.

a. Ethernet Using Serial Protocol • To Extract Wheel Weights & Vehicle Presence Flags

b. Ethernet Using Intercomp Supplied API (Application Program Interface) • Easy-to-Use Tool for Software Development in a Windows-Based Application • Settings are Configurable & the API provides Complete Vehicle Reports including Wheel Weights, Axle Weights, GVW, Axle Spacing & Speed

Intercomp Strip Scales are Offered as Components to be Integrated with Third-Party Electronics or as Part of a Complete WIM System

Complete WIM Systems

Identify & Flag Potential Offenders in Near Real Time

Access Information from a Remote Location via the Web

Measure Axle Weights, Spacing, Configuration & GVW

Capture Vehicle Images, DOT Numbers & License Plate

Description Protocol API WIMLOGIX Pro VWIMWheel LoadAxle LoadGross Vehicle WeightSpeedCenter-to-Center Spacing between AxlesVehicle Class (via Axle Arrangement)Site Identification CodeLane & Direction of TravelDate & Time of PassageSequential Vehicle OrderViolation CodeAxle-Group LoadEquivalent Single-Axle Loads (ESALs)Class-Specific, User-Definable Weight ViolationsSystem Requirements ANY .NET ANY ANYTime Frame REAL TIME REAL TIME DAILY REAL TIME

*Data Fields & Output Format are Customizable

Fully Provided

Handled by Customer Software




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Examples of Scale Layouts

Standard Layout2-Pairs of Scales

Staggered LayoutSingle Pair of Scales

Staggered Layout2-Pairs of Scales



In-Road Installation is Straightforward & Quickly Accomplished with Minimal Time & MachineryStrip Scale Installation Configurations

Intercomp ASTM and COST Compliance

DescriptionASTM 1318

Type IIIASTM 1318

Type IIASTM 1318

Type ICOST 323

A(5)COST 323

B+(7)COST 323

B(10)

Speed (if applicable)

10-80mph (16-130km/h)

15-80mph (24-130km/h)

10-80mph (16-130km/h) Not Required Not Required Not Required

Gross-Vehicle Weight ± 6% ±15% ±10% 5% 7% 10%

Axle-Group Load ±10% ±20% ±15% 7% 10% 13%

Single Axle ±15% ±30% ±20% 8% 11% 15%

*NOTE: System accuracy is dependent upon installation and site construction in accordance with Intercomp methods and site requirements.

Installing the Intercomp WIM strip sensors is straightforward and can normally be completed in 8 hours completing the following steps:

1. Layout and mark the system of sensors, cables and loop detectors. The sensors are typically placed 10ft (3m) apart and a loop sensor placed 3ft (1m) from the first set of sensors. Marking the roadway can be accomplished using a combination of tape, paint, chalk, markers and a tape measure.

2. Cut slots for sensors using an asphalt/concrete saw. The material between the saw cuts must be removed for the sensors using a chisel or jackhammer.

3. Clean slots. The slots must be free of any loose material and dry prior to placing sensors or grout. The depth, width, length and straightness must be confirmed.

4. Place sensors. The surface of the sensor must be slightly above the roadway surface to allow for sanding flush.

5. Pour epoxy grout. Thoroughly mix epoxy parts A & B with silica sand. Pour grout around sensors. For cold weather installations, a polyurethane grout may be used in place of the epoxy.

6. Cut slots for inductive loop detectors. (This may be done in the earlier step after sensor slots are cut.)

7. Place loops and cover with loop sealant.

8. Grinding the surface of the sensor. Confirm that the grout has cured—normally about 2 hours but dependent on temperature. A belt sander is used to sand down the surface of the sensor platform until flush with the roadway.

Intercomp Strip Scales can be installed in a variety of configurations. Ranging from Data Collection and Enforcement to Ports of Entry, the scales can conform to your specific application and site requirements.

Utilizing Strain Gauge Technology, one can expect a high degree of accuracy coupled with temperature compensated stability of the Intercomp sensors over time.

System Accuracy for a WIM system is dependent on many factors, such as sensor performance, installation quality, vehicle suspension, roadway condition, and scale configurations in the roadway.

Performance of Intercomp systems tested at multiple sites have been found to meet or exceed:• ASTM 1318 Type III requirements of ± 6% GVW• COST 323 A(5) requirements of ± 5% GVW

Installation NotesThe user is required to provide site conditions which will enable proper performance of the WIM sensors. Special consideration to horizontal and longitudinal alignment, pavement condition, lane width, surface smoothness, and pavement structure among others. These and other factors for considerations are detailed in ASTM1318-09 section 6 and Intercomp recommends compliance with these standards when selecting the proper sight in order to achieve optimal performance.

The Intercomp WIM system is less susceptible to poor road conditions like rutting. Strip scales have been installed in asphalt with significant rutting yet still exceed ASTM Type III accuracy. Regular inspection of the road service should be made and rutting progression may require additional grinding of the sensors to match the road surface followed by recalibration. Intercomp recommends adherence to ASTM.

Sensor Installation

Accuracy Requirements

Saw Cutting

Placing Sensor

Sanding Flush

Made In U.S.A.


© 2015 Intercomp Company 700733Printed in the U.S.A.

[email protected]: +1 763-476-2531Toll Free: 800-328-3336

Specifications subject to change without notice.


2.8˝ (70mm)

4.2˝ (107mm)

59, 69˝, 79˝ (1,500mm), (1,750mm), (2,000mm)

2.8˝ (70mm)

4.2˝ (107mm)

59, 69˝, 79˝ (1,500mm), (1,750mm), (2,000mm)

2.8˝ (70mm)

4.2˝ (107mm)

59, 69˝, 79˝ (1,500mm), (1,750mm), (2,000mm)

Weight

1.5m Scale 50lb (22kg)1.5m Scale with 100´ Cable 58lb (25kg)1.75m Scale 62lb (28kg)1.75m Scale with 100´ Cable 70lb (31kg)2.0m Scale 71lb (32kg)2.0m Scale with 100´ Cable 79lb (35kg)

Dimensions

Length 59˝, 69˝, 79˝ (1.5,1.75,2.0m)Width 2.75˝ (7.0cm)Height 4.2˝ (10.6cm)

General Data for Scale

Cable Length 100 to 300´ (25 to 100m)Connector MIL-C-26482 (8-pin Metal Cylindrical Connector, Bayonet Quarter Turn Lock)Degree of Protection IP 68EN60529

Scale

Sensitivity (Nominal) 0.75 (0.825)m V/V at 6000lb (3000kg)Output Variance over the Length of Scale <0.5±%Linearity <0.1±% FSOHysteresis <0.2±% FSOOperating Temperature Range -40 to 175 ˚F (-40 to 80˚C)Temperature Coefficient of Sensitivity 0.002 (0.0036) ±% of Load/˚F (˚C)

Electrical Specifications

6-Conductor Cable: ± Excitation, ± Signal, ± Sense, plus Shield Ratiometric mV/V output, 1mV/V @ 8,000lb TypicalBridge Resistance: 60 to 170 ohmsRecommended Excitation: 5-10V

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