On-board scales are mobile weighing systems that have been integrated into a vehicle, such as a flatbed truck or semi-trailer. [1] In the United States, such scales are used primarily as a self-check for weight compliance. Thus the operator can use the scale to determine the weight of the vehicle as it is loaded. [2] This enables the operator to avoid penalties by complying with state weight laws, while still transporting the maximum allowable weight. Weight laws are based on safety considerations; in the United States, the Federal Highway Administration requires each state to certify its enforcement of weight laws. [3] In addition, some states allow on-board scales approved under the National Type Evaluation Program (NTEP) to be considered legal for trade. [1]
The convenience of being able to weigh at the loading site is a key factor in the acceptance of on-board scales. Other factors include:
For refuse vehicles and fleets, the additional benefits of on-board scales include the following:
On-board scales sometimes appear in non-commercial applications. In one such, the Federal Motor Carrier Safety Administration used an on-board scale in 2009 on a technology demonstration vehicle. [6] The scale was one among several systems intended to provide information for researchers developing tools to determine the safety fitness of a vehicle. [7] Considering an unrelated possible non-commercial application, in 2015 the Federal Highway Administration wrote: "Recording and collecting data from on-board load cells can provide a metric for [weight law] compliance." [8]
On-board scales have been used on vocational trucks a at least since 1985. Among the first industries to use these scales were logging operations, in which the difficulty of determining the weight of newly cut logs, with their varying density and moisture content, was problematic. Avoiding overweight tickets by weighing when loading the logs was the incentive for using these scales. As more states began more rigorously enforcing weight limits in the early 1990's, other vocational trucking industries, such as waste hauling and aggregate hauling, began to install on-board scales. [9]
In 1987, "On-Board Load Cell" received a US Patent. This system was based on the application of a strain gauge to a sensor mounted to a vehicle's frame. The measured strain is described as "being representative of the weight of the vehicle load." [10] Two years later, in 1989, "A Vehicle Mounted Load Indicator System" received a US Patent. This system was based on the air pressure in a truck's air suspension. It relied on calibration and claimed an accurate reading of the weight of the carried load, transmitted to a readout. [11] On-board scales using the technology described in this patent were first sold in 1991. [12]
Already by 1995, the Society of Automotive Engineers was publishing a "History of On-Board Electronic Truck Scales and Future Design Trends". This review's abstract notes that newer on-board scale systems included calibration data in the load sensors, which would function as part of an on-truck computer network. [13] Thus, a calibrated load sensor on a trailer or semi-trailer could be attached to any tractor that could receive the trailer sensor's weight transmission over the network. Acceptance of on-board scales increased to the point that in 2008, for instance, all thirteen comments from poultry growers and agricultural associations, concerning a proposed U. S. Department of Agriculture rule, requested that the Department "not permit the delivery of ... feed for more than one grower on a single truck unless the truck has an on-board scale and weighing system, specifically when feed is taken from one farm directly to another." [14] [emphasis added.]
Load-cell scales are based on electronic load cell transducers, and can be mechanical or strain-gauge. There is a wide variety of scale types that can be built with load cell technology. For example, in vehicles with spring suspension, payload scales commonly use load cells. As with other electronic scales, the weight may be transmitted to an operator readout. [13] It may be further transmitted via a wide area network to a company office or corporate headquarters.
Electronic scales with PSI sensors measure air pressure in a vehicle's air suspension. [11] The scale relays this data to a receiver hardwired into the cab, [13] or wirelessly to a handheld unit such as a smart phone, either of which will interpret the data and display axle weight(s) and/or gross vehicle weight. Data may be further transmitted via a wide area network to a company office or corporate headquarters.
These are scales that determine the weight of the contents of a waste bin as it is being loaded onto a waste hauler truck. Their sensors, customized by each scale manufacturer, are generally based on strain gauges. They may use temperature sensors to allow for correct results with varying tempeatures. [15] As with other electronic scales, the bin weight may be transmitted to an operator readout, or via a wide area network to a company office or corporate headquarters.
These non-electric gauges are analog (dial-face), and include versions that can be calibrated for accuracy. Suitable for air-ride applications, they show on-the-ground weight in pounds (LBS) or kilograms (KG) instead of standard PSI.
Air-suspension PSI gauges are used on commercial trucks and semi-trailers where accurate weights are not as critical. These are not scales as such, but may be usable for estimating weight.
On-board scale manufacturers are located on most continents. Channels of distribution for these scales include Original equipment manufacturer (OEM) sales through truck or trailer companies as either a standard part of the vehicle or an option. Truck dealerships or service centers may provide the scales as an aftermarket option, including to truck fleets as well as individual truck owners.
A semi-trailer truck is the combination of a tractor unit and one or more semi-trailers to carry freight. A semi-trailer attaches to the tractor with a type of hitch called a fifth wheel.
A truck or lorry is a motor vehicle designed to transport freight, carry specialized payloads, or perform other utilitarian work. Trucks vary greatly in size, power, and configuration, but the vast majority feature body-on-frame construction, with a cabin that is independent of the payload portion of the vehicle. Smaller varieties may be mechanically similar to some automobiles. Commercial trucks can be very large and powerful and may be configured to be mounted with specialized equipment, such as in the case of refuse trucks, fire trucks, concrete mixers, and suction excavators. In American English, a commercial vehicle without a trailer or other articulation is formally a "straight truck" while one designed specifically to pull a trailer is not a truck but a "tractor".
Telemetry is the in situ collection of measurements or other data at remote points and their automatic transmission to receiving equipment (telecommunication) for monitoring. The word is derived from the Greek roots tele, 'far off', and metron, 'measure'. Systems that need external instructions and data to operate require the counterpart of telemetry: telecommand.
Commercial vehicle operations (CVO) is an application of intelligent transportation systems for trucks. It would allow trucks and buses to travel without having to stop for weight, credential, and safety checks, by using highway sensors to check them automatically as they are driven at prevailing speeds.
A dashboard is a control panel set within the central console of a vehicle, boat, or cockpit of an aircraft or spacecraft. Usually located directly ahead of the driver, it displays instrumentation and controls for the vehicle's operation. An electronic equivalent may be called an electronic instrument cluster, digital instrument panel, digital dash, digital speedometer or digital instrument cluster. By analogy, a succinct display of various types of related visual data in one place is also called a dashboard.
A scale or balance is a device used to measure weight or mass. These are also known as mass scales, weight scales, mass balances, massometers, and weight balances.
A falling weight deflectometer (FWD) is a testing device used by civil engineers to evaluate the physical properties of pavement in highways, local roads, airport pavements, harbor areas, railway tracks and elsewhere. The data acquired from FWDs is primarily used to estimate pavement structural capacity, to facilitate overlay design or determine if a pavement is being overloaded. Depending on its design, a FWD may be contained within a towable trailer or it may be built into a self-propelled vehicle such as a truck or van. Comprehensive road survey vehicles typically consist of a FWD mounted on a heavy truck together with a ground-penetrating radar and impact attenuator.
Weigh-in-motion or weighing-in-motion (WIM) devices are designed to capture and record the axle weights and gross vehicle weights as vehicles drive over a measurement site. Unlike static scales, WIM systems are capable of measuring vehicles traveling at a reduced or normal traffic speed and do not require the vehicle to come to a stop. This makes the weighing process more efficient, and, in the case of commercial vehicles, allows for trucks under the weight limit to bypass static scales or inspection.
On-board diagnostics (OBD) is a term referring to a vehicle's self-diagnostic and reporting capability. In the United States, this capability is a requirement to comply with federal emissions standards to detect failures that may increase the vehicle tailpipe emissions to more than 150% of the standard to which it was originally certified.
A tire-pressure gauge, or tyre-pressure gauge, is a pressure gauge used to measure the pressure of tires on a vehicle. Proper tire pressure is crucial for vehicle safety, fuel efficiency, and tire longevity. Tire gauges come in various types, including analog, digital, and dial gauges, each offering different features and accuracy levels. Tire-pressure gauges can be used both professionally and casually and come in many different sizes.
A load cell converts a force such as tension, compression, pressure, or torque into a signal that can be measured and standardized. It is a force transducer. As the force applied to the load cell increases, the signal changes proportionally. The most common types of load cells are pneumatic, hydraulic, and strain gauge types for industrial applications. Typical non-electronic bathroom scales are a widespread example of a mechanical displacement indicator where the applied weight (force) is indicated by measuring the deflection of springs supporting the load platform, technically a "load cell".
A tire-pressure monitoring system (TPMS) monitors the air pressure inside the pneumatic tires on vehicles. A TPMS reports real-time tire-pressure information to the driver, using either a gauge, a pictogram display, or a simple low-pressure warning light. TPMS can be divided into two different types – direct (dTPMS) and indirect (iTPMS).
A weigh station is a checkpoint along a highway to inspect vehicular weights and safety compliance criteria. Usually, trucks and commercial vehicles are subject to the inspection.
A truck scale (US), weighbridge (non-US) or railroad scale is a large set of scales, usually mounted permanently on a concrete foundation, that is used to weigh entire rail or road vehicles and their contents. By weighing the vehicle both empty and when loaded, the load carried by the vehicle can be calculated.
In road transport, an oversize load is a load that exceeds the standard or ordinary legal size and/or weight limits for a truck to convey on a specified portion of road, highway, or other transport infrastructure, such as air freight or water freight. In Europe, it may be referred to as special transport or heavy and oversized transportation. There may also be load-per-axle limits. However, a load that exceeds the per-axle limits but not the overall weight limits is considered overweight. Examples of oversize/overweight loads include construction machines, pre-built homes, containers, and construction elements.
Brake-by-wire technology in the automotive industry is the ability to control brakes through electronic means, without a mechanical connection that transfers force to the physical braking system from a driver input apparatus such as a pedal or lever.
A checkweigher is an automatic or manual machine for checking the weight of packaged commodities. It is normally found at the offgoing end of a production process and is used to ensure that the weight of a pack of the commodity is within specified limits. Any packs that are outside the tolerance are taken out of line automatically.
The Federal Bridge Gross Weight Formula, also known as Bridge Formula B or the Federal Bridge Formula, is a mathematical formula in use in the United States by truck drivers and Department of Transportation (DOT) officials to determine the appropriate maximum gross weight for a commercial motor vehicle (CMV) based on axle number and spacing. The formula is part of federal weight and size regulations regarding interstate commercial traffic. The formula is necessary to prevent heavy vehicles from damaging roads and bridges. CMVs are most often tractor-trailers or buses, but the formula is of most interest to truck drivers due to the heavy loads their vehicles often carry.
A specialized set of jargon describe the tools, equipment, and employment sectors used in the trucking industry in the United States. Some terms may be used within other English-speaking countries, or within the freight industry in general. For example, shore power is a term borrowed from shipping terminology, in which electrical power is transferred from shore to ship, instead of the ship relying upon idling its engines. Drawing power from land lines is more efficient than engine idling and eliminates localized air pollution. Another borrowed term is "landing gear", which refers to the legs which support the front end of a semi-trailer when it is not connected to a semi-truck. Some nicknames are obvious wordplay, such as "portable parking lot", in reference to a truck that carries automobiles.
A force gauge is a measuring instrument used to measure forces. Applications exist in research and development, laboratory, quality, production and field environment. There are two kinds of force gauges today: mechanical and digital force gauges. Force Gauges usually measure pressure in stress increments and other dependent human factors.