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.

Topside Housekeeping
Take a walk around the outside of the truck scale. Examine the entire deck, scale pit, foundation and approaches for any major structural or surface problems.  Scale owners with scales that have any deterioration need to fix them right away.   Any deck and approach repair is not merely cosmetic; those damages will have a negative effect on the scale.  Flaking rust and crumbling concrete falling into the pit will add maintenance costs now, but in the future they will reduce the scales’ usefulness.

Check Deck Clearance
If you have a pit scale, while still outside the pit, use a crowbar to check the weighbridge for free movement both with and without a vehicle on the scale. If binding seems to be an issue, check the pit wall-to-deck clearance. If clearance looks good all around, with no debris between the walls and the deck, you’ve done all you can topside. The binding problem is coming from below. Get your boots, gloves, hornet spray and lights, and get ready to head into the pit to look things over (or better yet, call your scale guy instead).  Just remember to check the oxygen level in the pit before you go down in the pit.

Keep it Clean Under the Truck Scale
The most common cause of incorrect weighments is debris in the pit binding movement. Clean all dirt from each component. Remember, even though most scales these days are electronic, they still have moving parts underneath. Load cells still need to be able to deflect through their capacity range.  We recall the story we heard recently of a customer requesting a service call to figure out what was causing his scale to weigh incorrectly. It was a pretty urgent situation because the scale had been red tagged and his whole business was shut down while they tried to figure out the problem. Well, the service guy soon discovered the problem – a single piece of gravel wedged between the weighbridge and side of the foundation!

To cut down on future problems, the scale owner needs to invest in flexible T-Grip or T-Strip molding. These moldings, while being flexible enough to work with the movement of the scale, will keep debris from causing problems and eventual damage to the truck scale. Depending on the scale design, the molding might only be necessary to cover the end gaps where the trucks enter and exit the scale. Scales weighing open trucks or messy operations will also need side molding to protect against spillage falling into the pit.

Load Cell / Lever Hybrids
When you have a hybrid lever scale converted to digital readouts with an S-beam load cell, you need to check a few more items during the inspection.  Replace any damaged load cell cables rather than splicing them. Cable splices are prone to moisture entry, leading to a new host of problems. For further moisture safeguards, replace j-box desiccant, or fill the box with Waterguard Gel.

If rodent or radio frequency interference are problems, switch to a cable offering both rodent protection and EMI/RFI protection.  We recommend the EL147RP load cell cable. For protection against rodents only, run the cable through conduit or in the Rice Lake SURVIVOR® Cable Armor.  Finally, get a complete scale calibration with certified test weights with proven accuracy.  Actually, your best choice is to set up a quarterly service agreement with your local scale company.  They have the expertise and equipment to keep your truck scale running smooth year round.  In central North Carolina, the choice would be Central Carolina Scale out of Sanford, NC.

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.

The RoughDeck AX uses four corner-mounted, FM-approved load cells, with the cells recessed into the frame channels for protection. Also included is a signal-trim summing board enclosed in a stainless steel, NEMA 4X junction box for any necessary corner corrections. The RoughDeck AX comes pre-trimmed; so corner corrections should not be necessary.

Load cell cables are enclosed in conduit through the main channels, and held down with replaceable cable ties near each corner, eliminating the possibility of cable damage in portable applications.  Because of the possibility of foot and load cell damage from forklift tines, the scale should always be lifted from above with chains through the eyebolts when setting up the scale. The adjustable carbon steel captured ball feet are used to assist with self centering the scale as vehicles drive on.  The four access ramps for the RoughDeck AX come equipped with a heavy duty treaded top plate.

The scale must not be loaded beyond its capacity, even momentarily. Do not select a site where overweight loads would have to maneuver to avoid crossing the platform. Avoid areas where the scale might receive damaging side impacts or shock damage. Avoid areas where water may damage a scale not meant for a washdown environment. The interface cable between the scale and the indicator must be protected against crushing, cutting, or moisture damage. If the chosen site has such potential dangers, some method of protection, such as running the cable in conduit, will be necessary. In operation, the scale must be level within 1/4 inch.  Either choose a site where the ground is close to this standard to avoid excessive shimming, or modify the ground at the chosen site to meet this standard.

iQUBE acts as a virtual watchman, continually monitoring scale performance. It provides immediate proactive event management to alert operators and technicians of potential inaccuracies or disturbing trends. When an irregularity is detected, the advanced diagnostics will trigger an on-board LED that will change from green to red, indicating which cell is affected. A specific diagnostic message will also display on the 920i when the two are paired together.

With open architecture and advanced connectivity, iQUBE works with existing analog scale systems, new scales, existing indicators and new user interfaces. To make integration easy, iQUBE interfaces using today’s common serial interfaces including RS-232, RS-485, analog, fiber optics and RF wireless. Additionally, on-board Ethernet TCP/IP provides seamless integration from your front office to factory floor. If your business is heavily vested in fieldbus technology, bundle an 820i/920i digital indicator/controller with your iQUBE to easily adapt to DeviceNet™, Profibus® DP, and Allen-Bradley® Remote I/O options.

For concrete deck scales, a concrete crew of three or four can normally pour, finish, and seal-cure the concrete deck surface of a 70′ scale in 2 – 3 hours. (Don’t forget, standard concrete reaches full strength after a 28-day curing period. At seven days, standard concrete reaches approximately 75% of its maximum strength and can handle moderate loads.) Final wiring connections can normally be completed the same day while the concrete is curing.  Please note these are just rough estimates and times may vary depending on many factors.

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.

Unlike check rod binding, bumper bolt displacement is easy to spot.  Bumper bolts need to be tight so they don’t move on their own, yet maintain clearance when the scale is both empty and loaded.  Seasonal temperature and weather changes can cause concrete and steel to expand and bumper bolts can bind tight against the contact area.  If binding occurs, adjust bumper bolts to maintain proper amount of clearance for all conditions. Rice Lake SURVIVOR scales do not have bumper bolts.

Binding is a common cause of inaccuracies. A rock as small as your big toe can become wedged between the foundation and deck.  Installing T-Strip molding between the deck and foundation can help keep debris from getting caught or falling down into the scale. Some above-ground scales have end cleanout plates that can be removed, allowing access to clean out debris that builds up on the foundation’s surface closest to the scale’s end.  The above examples are a great reason to contact an experienced truck scale sales and service company like Central Carolina Scale for your truck scale needs.

When deciding how often to have your scale tested, take into consideration your number of weighments, climate and the value of the product being weighed.  Aside from the actual calibration, most of the inspection will consist of you or your scale technician conducting a visual inspection of the scale, foundation and surrounding area.  Every vehicle scale should be calibrated and tested by a state-licensed servicing agent with no less than 25,000 pounds of certified test weights.  A lot of times it is ideal to use a company like Central Carolina Scale in Sanford, North Carolina  that has a scale test cart that can test different areas of the scale.