Rice Lake says, even as traffic climbs as high as 250 fully loaded trucks per day, expect no less than 25 years of solid service from any SURVIVOR OTR.  This celebrated weighbridge design combines convenient top access to load cells, a low profile for easy approaches, and self-setting connectors for quick installation and future expansion.

The SURVIVOR OTR Series truck scale is an outstanding design that incorporates the most advanced engineering and production technology to manufacture the highest quality vehicle weighing system in the marketplace. The OTR Series scales don’t sacrifice quality for price. Both the OTR concrete and steel deck models boast wide flange I-beam construction. The wide flange beam construction helps minimize span deflection and lengthens the life of your truck scale. Both the concrete and steel deck models are built to be the “Toughest Scales on Earth.”® SURVIVOR OTR Series truck scales are designed to accommodate up to 250 trucks per day for 25 years without weighbridge fatigue. This is equivalent to more than 2 million weighments.

Engineered with state-of-the-art robotics, Cardinal’s EPR+ Plus Truck Scale represents the culmination of 60 years of scale manufacturing experience. Available in impervious hydraulic or electronic load cell types, the EPR+ Plus’ durable baked-on, anti-corrosion powder paint stands the test of time. The legal-for-trade NTEP EPR+ Plus arrives fully-prepared for installation and includes DB75000 lb stainless steel load cells standard, which are factory assembled. All Cardinal load cells can withstand the weight of up to 150% of published load cell capacity. A wide selection of EPR+ Plus capacities, platform sizes, and types are available from Cardinal Scale. In North Carolina, customers rely on Cardinal dealer, Central Carolina Scale for both sales and service of Cardinal Scales.

Both pit type and low profile scales offer a choice in platform material. Platforms may be constructed from concrete or steel plate or, in some cases, wood. The material you choose will depend somewhat on personal preference as well as the way you use your scale. The initial price of a concrete scale will be a little less than an equivalent scale with a steel platform yet when you add in the cost of the concrete and finishing labor, it will exceed the cost of its steel decked cousin. Concrete also requires a curing time which will delay the use of the scale but concrete is less slippery in wet weather, is not affected by most chemicals, doesn’t rust, requires little or no maintenance and provides years of service. Steel decks are usually constructed from checkered plate which gives extra traction in wet weather. In general, if your application calls for heavy loads and lots of them, concrete is the preferred material for the scale deck.

Scales are available in either full electronic or electromechanical models as well. Full electronic scales are directly supported by multiple load cells typically numbering 6 to 12 cells or more depending on the length of the scale. Electromechanical scales are supported by a series of bearings attached to ends of levers mechanically summing the forces applied to the scale platform. A summed force is applied to a single load cell. Most truck scales today are of the full electronic type simply because they are easier and less expensive to construct. Electromechanical scales are still available from some manufacturers and offer some unique advantages. The use of a single load cell makes the scale less susceptible to damage from lightning and they require less power to operate which means a simple battery operated weight indicator can be used when power is not available. Disadvantages of the electromechanical scale include the need for periodic maintenance or repair due to the wear in the bearings of the mechanical lever structure and higher initial cost. The full electronic truck scale has a lower initial price and is easier to work on since there is no complex lever system. The individual load cell signals of a full electronic truck scale must be summed to provide the total weight signal to the weight indicator. Summing of the load cell signals normally takes place within one or more junction boxes typically located at or near the scale. Because the outputs normally differ from load cell to load cell, it is necessary to make compensating adjustments which may become lengthy depending on the method used.

Finally, when choosing a truck scale, consideration should be given to the method of weighbridge restraint used. The weighbridge or scale platform must be constrained so that it does not slide off the supporting structure as a truck enters of leaves the scale. Although there are a number of ways of accomplishing this, the two most common are check rods and bumper bolts. Bumper bolt systems consist of an adjustable rod or bolt or similar device attached to the weighbridge and positioned such that it strikes the adjacent foundation or lower structure preventing further movement of the scale weighbridge. This is an effective and simple means of restraining the weighbridge but, to work properly, it must be periodically adjusted to maintain the proper clearance between the adjacent lower structure or scale foundation and bolt head. As the scale is used, this gap changes and must be adjusted to keep the restraint system operating properly. The check rod type of restraint system is a long thin rod that attaches the weighbridge to the surrounding structure preventing lateral movement of the weighbridge. The ratio between the length of the rod and its diameter is quite large allowing the rod to flex without affecting the accuracy of the scale. Unlike bumper bolts, check rods do not wear and therefore require little or no maintenance.

Truck scales are available in a wide range of sizes. Platform widths from 8 feet up are available while lengths often exceed 100 feet. You should select a platform size that is not only sufficient to weigh the trucks you currently have but large enough to weigh the trucks you may use in the future. Generally, widths of 11 to 12 feet are preferred for trucks used on the highway. Not only are scales of this width easier to ship, but they are approximately the lane width of many of our nation’s highways. Scales of greater width are available but are more expensive both in initial cost and in the costs associated with testing. Choose a length that is long enough to weigh the largest truck you anticipate weighing in the future. Remember, adding an extra 5 feet or so to the length seven years from now will be much more expensive than purchasing that extra length initially. Also, keep in mind that the scale must fit within the area you have allocated for the scale remembering to allow for a straight approach and departure from the scale preferably equal in length to the scale platform itself. It’s better to be a little large than too small.

Like platform size, weighing capacity should be selected based on your current and anticipated needs. There are two capacities associated with truck scales. The first, nominal capacity, is the total measurable load that can be distributed over the scale platform. Most truck scales have nominal capacities of 200,000 pounds which is more than sufficient to weigh highway trucks. Selection of the nominal capacity is normally not of concern since it is typically great enough to handle all but the most extreme loads.

As you can see, a lot of thought must take place when considering the purchase of a truck scale. If you are considering or looking for a used truck scale, you need to consider all the topics that were mentioned earlier. You also need to consider the fact that in most cases with a used truck scale, you are buying a scale with very little if any warranty and you are buying a scale that has had thousands and thousands of pounds of equipment driven over it for years. There is also the outdoor element factor that must be considered.  Finally, many times a specific concrete foundation must be poured to fit the used scale.  All of these factors must be considered and factored into your total cost of ownership.

Inspect load cell cables for damage. If damage is present, the seal is probably degraded as well. To combat this problem, some manufacturers offer rigid or flexible metal conduit to run the cable through, providing a layer of protection that’s nearly impervious to damage from rodents. Even though steel over braid cable provides more protection from damage than cable sheathed with polyurethane or plastic, they still need to be checked as well.

Weather is another enemy of load cell cables. When exposed to moisture, cables can become wicks. Water can be sucked through the cable’s length by capillary action until it enters the load cell or junction box. Once inside, it can damage components and seep into the inner layer of the cable. Wet cables may not cause signal distortion immediately, but they may slowly corrode the copper wires or shield beneath the insulation, causing big trouble sooner or later. Corrosion of the shield limits the cable’s effectiveness in blocking electromagnetic interference (EMI) and radio frequency interference (RFI). Corrosion of individual wires will degrade the signal. If you discover a wet home run cable or load cell, replace it. To help prevent moisture from entering the cell from the cable, bend the cable or flexible conduit downward to create a drip loop at the location just before it enters the cell.

Check the junction box (j-box) for internal condensation, is the most common moisture problem. This occurs from normal air exchanges from heating and cooling cycles, and over-aggressive washing that damages sealing components that haven’t been properly maintained. If left unchecked, wiring terminals and other components in the enclosure will corrode. Due to its material properties, a stainless steel j-box is more vulnerable to internal condensation. If stainless steel is not required, install a j-box with a fiberglass-reinforced polyester (FRP) enclosure. A desiccant bag in the enclosure will help control moisture.

The CLC rating is not a measure of weighbridge strength or rigidity, because weighbridge deflection is not measured in the NTEP test. It is irrelevant if the load weighbridge sags 1/10th of an inch, or 10 inches, as long as the scale weighs within the accepted tolerance. The scale’s CLC weight rating passes in either case. A high CLC rating could be given to an extremely flexible deck sitting on load cell mounts which are capable of accurately handling the side loading resulting from a severely sagging weighbridge.

The Rice Lake SURVIVOR® truck scale line boasts a 45 ton (90,000 pounds) CLC rating. With most legal highway weight limits being a fraction of Rice Lake’s rating, owners of a SURVIVOR scale can expect a long lifespan through the most rigorous weighing processes of two million weighments or more. NTEP provides a set of procedures for the uniform testing and evaluation of weighing equipment. For a truck scale to be NTEP-certified Legal-for-Trade, the entire truck is weighed, not just a single axle or group of axles. The SURVIVOR series is approved for up to 270,000 pound full scale capacity with a 90,000 pound CLC rating, earning NTEP certification up to 14 feet wide. NTEP has additional guidelines for truck scales, such as the required length of approach ramps. For clarification on your state’s requirements, contact a qualified dealer who can help you determine the best site for your scale to meet those guidelines. For North Carolina, contact Central Carolina Scale in Sanford NC.