We’re going to try & help you understand all the truck scale terminology that you need to know. Especially if you’re new to truck scales.
So let’s say your business has decided to purchase a truck scale in order to determine accurate and reliable vehicle weight for your application. That’s great! Understanding fundamental truck scale basics and how a truck scale works will help you know which questions to ask your local scale distributor to ensure you purchase the truck scale style that fits your needs with the options and accessories that can enhance your application.
Whether monitoring a vehicle’s weight for safety guidelines or to complete business transactions, you should know what the info determined by a truck scale means to your business.
For example:
Gross weight is the total weight of the vehicle and loaded product. Tare weight is the weight of only the vehicle. Net weight is the weight of only the loaded product.
Today, most scales at solid waste facilities or recycling centers are installed with above ground or concrete pit foundations. Depending on state or regional requirements, scales can also be installed in a shallow pit, as opposed to the deep pit required by older mechanical scales. A pit installation requires less space than an above ground scale since longer approaches are generally required for above ground configurations. However, pit-styles require sump pumps and drains, and are generally more vulnerable to corrosion due to potential standing water.
The truck scale’s driving surface is called the weighbridge. Weighbridges are composed of steel or concrete decks, and are typically manufactured in modular designs that are connected together during installation.
The indicator, also called a controller, or terminal, can display basic weight functions, as well as serve as the command center for a weighing system with truck in & out programs to control the entire truck scale system, including any remote displays and ticket printers.
Load cells are vital to truck scale performance. There are various types of load cells, but they all basically have the same function—to accurately measure weight on the scale. How do load cells work, you may be asking? All load cells take an analog measurement, and then that signal is converted to a digital output either at the load cell, junction box, or in the scale indicator. Load cells are typically constructed of steel and are integrated within the weighbridge, usually at the corners of each module.
A junction box properly manages multiple load cells. By matching the signal of each load cell and summing them into a signal that’s sent to the indicator, junction boxes equalize the system for accurate and reliable weight readouts.
We’re going to wrap up our entry on truck scale basics and terminology. I hope we made all this truck scale jargon a little easier to understand for those of you in the market for a truck scale. If you need some truck scale buying advice or scale recommendations, we are just a phone call or email away.
The Basics of Load Cell Wiring and Trimming Load cell wiring and trimming are critical to a weighing system’s accuracy and should always be performed by trained scale technicians.
However, general load cell wiring knowledge can help you better understand how your weighing system works and how potential errors occur.
Load cell cables typically have four or six wires. Both versions have positive and negative signal and excitation lines, though a six-wire cable also has positive and negative sense lines. Sense lines are linked to the sense connections of the system’s indicator, sometimes through a junction box, allowing the indicator to sense a load cell’s actual voltage. If there is a voltage drop between the indicator and load cell, the sense lines send that information to the indicator, which automatically adjusts voltage. This compensates for the loss of voltage or amplifies the return signal to compensate for loss of power to the load cell.
Load Cell Color Codes
Load cell wires are color coded to help ensure proper connections. Different load cell brands use different color codes, which is why there are load cell wiring guides available for scale technicians to use during installations.
Adjusting / Trimming / Summing Load Cells
Load cell trimming is sometimes called load cell summing because it involves tying or summing multiple load cell output signals together. This happens in a junction box, also known as a summing box, which sends one system signal to the weight indicator. It’s necessary to trim load cells in a multi-cell system when the weight distribution to each load cell isn’t equal. Click the following link for more about how a load cell works.
For example, in vessel loading processes, the presence of agitators or the type of material, such as powder, can affect how material and weight are distributed to each load cell. Additionally, it’s nearly impossible to make every load cell exactly alike. Tolerances in the manufacturing process allow for some variation in individual load cell specifications, which, if trimming isn’t applied, doesn’t allow for the accuracy necessary for most applications.
Signal trimming is the most common and popular type of load cell trimming because it is the easiest to use. Signal trimming is compatible with nearly all indicators and is relatively unaffected by temperature changes or excessive system vibrations. It involves adding a relatively high parallel resistance between the signal of each load cell, which creates a leakage path that diverts some of the available load cell signal away from the indicator. More load cell signal will be available to the indicator as parallel resistance increases.
Be sure to visit Central Carolina Scale.com often for all your weighing related needs.
It may be tempting to save a few dollars by purchasing an inexpensive floor scale imported from overseas. After all, the capacity and size may appear to be the same as the more expensive brand and the pictures of the products look virtually identical! So, what is it that really separates the Expensive Floor Scale and makes it better than the Less Expensive Floor Scale?
Imported Floor Scales Worth the Hassle?
This is something we’ve discussed before actually. We’ve seen just about every possible brand of platform scale over the years. Some of the scales shipped over from China are decent. Some aren’t as good. Some of the weight indicators are not very user friendly or reliable.
When it comes to floor scales, we generally rank them in different levels of floor scale quality. For example, top of the line would be the B-Tek Clydesdale or Rice Lake Roughdeck. Second level might be the Pennsylvania 6600 or Digi Summit 3000. Third level might be a Brecknell floor scale. Lowest level would be brands & models that we won’t mention…
Do I Need Legal for Trade?
First thing that you want to determine is NTEP legal for trade status. You will need to determine if your floor scale needs to be legal for trade. Some cheap floor scales you find on the internet are not legal for trade. It’s almost always a good idea to buy a legal for trade floor scale. In our opinion, it’s a good idea to purchase a platform scale that is capable of earning a Certificate of Conformance (CoC#).
Quality Scale Components Make a Difference
Next, compare the electronic components that make up the scale There are typically four load cells in each floor scale, one in each corner. Some lower-quality floor scales use load cells that you cannot replace just one of the cells. When checking for causes of scale weight error, if one goes bad, all four need to be replaced! Some manufacturers also use cheap load cells that are sourced overseas and have little if any documentation. It is important to use quality components to ensure longevity and accurate weighing. Some of the load cell brands we recommend include Revere Transducers and Rice Lake Weighing Systems among others.
Next, is the Junction Box with Summing Board. Does the scale you are considering have a junction box with summing board inside? The purpose of the junction box is so you can adjust the output of the loadcells so the scale weighs the same regardless of where the load is placed on the scale platform. If a loadcell needs to be replaced the junction box allows you to easily remove the bad cell and replace it with the new one and wire it back into the scale without having to unwire and re-solder all the cells back together. Some cheap platform scales just tie the wires together and eliminate the junction box in their design. We do not recommend this and it makes replacing a load cell and/or troubleshooting difficult.
Heavy Duty Steel Platforms Can Last for Many Years
Maybe equally as important as the scale components is the build of the scale itself — The steel weighbridge. Pay attention to the shipping weight of the scale. The heavier the scale typically means the better build quality.
Thicker deck plate and substructure is an important key to giving the load cells the structure they need to perform properly. If the floor scale is flexing and bending, the scale will not last and it will cause inconsistent weights. Thin, short welds are also a sign of mass-produced low-quality scales. These welds could break over time and cause inconsistent weights and/or significant down-time.
Weight Displays are an Important Part of the Scale System
The last item, and possibly most important to consider, is the indicator that comes with the floor scale. Is an indicator included in the price? If it is, there are a few questions to ask. Is the indicator calibrated to the scale base? Does the indicator include a user manual that is easy to read and understand? Do you need a certificate of calibration with certified weights for your ISO program? Do you need a full numeric keypad to enter a tare weight? Do you want to tie your scale into a computer or printer?
These are all common issues people come across when purchasing a cheap floor scale online. And, many times this leads them to spending significantly more money with their local service company to get their scale up to the actual functionality they need.
In our experience, customers usually experience a better overall scale buying experience by contacting an experienced scale sales person first. Price and budget can certainly be an important component. But, scale construction, quality components and more can also be considered as well. By working together with a scale company, you get the type of industrial floor scale that you actually need. You also get any custom features that you may require.
As always, Central Carolina Scale would like you to make the most informed decision possible to help your business. We are here to help you with any questions you may have to help guide your decision.
Our local scale calibration and repair customers throughout the central sections of North Carolina are very important to us. We typically stock 90%+ of the standard replacement scale parts that they may need.
However, if you have certain types of scales that aren’t as common or if you have a large number of scales or load cells at your facility… then it can be a smart strategy to keep some spare parts on hand to minimize any downtime. Call us today (919) 776-7737 to determine what replacement scale parts and hardware you need.
If your business relies heavily on your scale(s), then it’s imperative to stock some spare parts to minimize unplanned downtime. Downtime can be a real problem. Especially for certain businesses and at certain times.
Our suggestion is to contact our scale repair & service department and discuss your scales and down time and identify any spare parts that are really important or any spare parts that are difficult to obtain.
Unfortunately, customers often don’t think about downtime and potential failures until it’s too late. This year, we’ve seen some scales that were down for weeks while they wait for replacement parts to arrive from the manufacturer. This is why we encourage you to contact us to determine what items you need to stock.
Supply Chain Issues & Longer Lead Times!
You’ve likely experienced this in your business and we certainly have as well. Between rising prices and labor shortages and continued medical issues, it’s greatly affected the manufacturing and logistics industries. We have seen parts that used to be a 2 day lead time, turn into a 2 month lead time. This is why it’s important to contact us today and discuss what item(s) you need to stock so you can experience the least amount of down time as possible.
These are real concerns that in the past we haven’t had to think much about. However, with certain lead times at record levels… it just makes good sense to plan.
How much money could you potentially lose if your scale is shut down for a couple weeks? What about a couple of months? When you think about it in those terms, if can sometimes lessen the burden of spending a few thousand dollars to keep some spare scale parts on your shelf.
Which Spare Replacement Scale Parts should I Keep on my Shelf to Minimize Unplanned Downtime?
The truth is that spare parts can be expensive to keep on your shelf. We see this every year when we analyze our inventory and determine what items sold and what items collected dust.
And, as mentioned earlier, we stock A LOT of replacement scale parts like load cells, weight indicators, main boards, etc… But, the truth is that we can’t possibly stock every single spare part that every single customer of ours might need. That’s why it’s important to discuss this with our service department and determine what item(s) we feel you should stock.
This will cost you some money but we would argue it’s still not as expensive as a few weeks of unplanned downtime with a broken down truck scale. It goes without saying, but this suggestion regarding spare parts also needs to factor in how important a particular scale is to your business.
For example, if you are a metal recycler, one broken floor scale might be easier to manage since you likely have several other floor scales you could use. However, if you have a broken down truck scale and that’s the only truck scale you own, that item would be much harder to do with out. In our opinion, if you want to reduce potential down time… you might want to stock the following items:
Replacement Weight Indicator
Digital Weight Indicators are items that often break or get damaged on job sites. Sometimes the damage is through lightning, while other times it’s from being knocked off a desk and dropped to the floor or perhaps being run over or hit. Other times “nobody knows what happened“….. In any of these scenarios, the weight indicator is a very important component to a scale system. Without a functioning scale controller, your employees can’t see the actual weight on the scale platform.
To take it one step further… some companies use very sophisticated weight controllers that are programmed for various tasks like truck in/out or truck storage, batching, etc… Those scale indicators need to function and if they fail, there needs to be a replacement available ASAP. For applications like this, it can be a good idea to stock a spare indicator with the custom software installed.
Replacement Scale Boards
Boards are one of the most essential components to a scale. These boards connect all of the components required to power the scale. It’s smart to have the main board, display board, analog output board, summing board(s), remote display main board, etc…. This will vary depending on the customer and which scale(s) you have.
Replacement / Spare Load Cells
We have to include load cells on this list since they are so prevalent in most weighing systems. However, in a lot of cases, we do have stock for most standard strain gauge load cells. This is a great example where we recommend contacting us and discussing what we have in stock and what we recommend that you stock. For example, of the past several years there have been multiple new digital truck scales available which take a digital load cell, cables, and digital weight indicator. Similar challenges exist with hydraulic truck scale replacement parts as well.
Bottom line:
if you have a scale or multiple scales that are very important to your business process, then you need to contact us and discuss recommended spare parts and what we stock versus what we suggest that you stock.
A little forward thinking can minimize the unplanned downtime and it could mean the difference between a few hours of downtime or multiple weeks without a scale.
And these spare parts discussions (they can be phone calls or emails) probably need to happen every year since things change. Items become obsolete, new products get purchased, etc…
Responsible for channeling both power and communication between the load cells and the indicator, load cell cables are an integral part of building a custom scale. Though not just any cable will work. See, load cell cables are selected based on the distance between the two parts, as well as certain environmental conditions like temperature, contact with abrasive or flammable materials, or even rodents.
Before you can know the right type your custom scale project needs, it is best to have an understanding of the different types of load cell cables available.
4-Wire Load Cell Cable
Perhaps the most common cable, the 4-wire load cell cable is used primarily for short distances. As its name suggests, this type consists of four wires:
Power (excitation) +
Power –
Signal (output) +
Signal –
Once connected, the cable should run from the scale to the indicator display. These wires are calibrated and designed to handle the surrounding temperatures. Many custom scale projects use the 4-wire load cell cable since it is more affordable and suitable for most scales. However, should you need additional length or if your scale is in an unpredictable environment, you may need to reconsider the type of load cell cable you are using.
6-Wire Load Cell Cable
Designed for longer distances and more difficult settings, the 6-wire load cell cable offers a lot more options. Again, as the name suggests, these load cell cables have six wires. They contain the four found above, as well as positive and negative sense wires. The long distances that 6-wire load cell cables cover can subject them to changes in resistance, temperature, and dips in voltage. The addition of these two sense wires helps to keep things flowing steadily.
Because they are not thermally compensated as the 4-wire load cell cables are, the 6-wires can be cut and used alongside other cables with no issue – making them perfect for larger commercial custom scale projects.
Types of Load Cell Cable Shielding
While 6-wire load cell cables offer a lot of benefits when designing a project, it is important to note the surrounding environment and opt for shielding that will protect the cable from any outside environmental factors. Below are the most common types of load cell cable shielding.
Hostile Environment Cable
Hostile environment cable is best used in environments that are, well, hostile. Depending on where the scale is being used, the cables may come in contact with harsh or abrasive substances, such as fuel, ether, or even salt. Over time, these substances can damage the cables.
Hostile environment cables are created with a polyurethane jacket that acts as a barrier against these damaging substances, keeping the cable safe and the scale running smoothly.
Rodent Protection Cable
Rodents and their incessant chewing may seriously interfere with a scale’s functionality. If in an environment where there are rats, mice, or other pests, the load cell cable may become enticing – leaving you with hefty costs to replace some or all of the cable.
Rodent protection cable is a type of cable that protects against this pesky situation. The outside layer of the cable is a braided shield making it difficult to chew. And, as an added defense, it is coated with a chemical that will discourage them from wanting to ever take a second bite.
Intrinsically Safe Cable
Flammable gases or liquids or generally hazardous materials can be damaging to load cell cables, requiring added security in the form of a jacket. For intrinsically safe cables, industry-standard blue double jackets are used to protect the cables from exposure to these dangerous materials.
High-Temperature Cable
In environments where the temperatures fluctuate or reach extreme highs, load cell cables need an outer covering that will protect the wires regardless of how hot it gets. A high-temperature cable is designed with a fluorinated ethylene propylene (FEP) jacket that insulates the wires and can withstand the heat without getting damaged.
Choosing the Right Load Cell Cable
Choosing the right load cell cable is important. If you would like to learn more about the different types of load cell cables or have questions about what would work best for your project, contact our sales department at (919) 776-7737. After all, at Central Carolina Scale, we have the largest inventory of load cell cables in the industry.
Should I buy a truck scale with weigh bar sensors? The Avery Weigh-Tronix Weigh Bar® was designed to overcome the shortcomings of the traditional strain gauge load cell and to provide the end user with a rugged, highly reliable and linear load sensing device at reasonable cost.
More than twenty years of extensive use in industrial, farm and transportation applications has demonstrated that the Weigh Bar has met these requirements. The unique, robust design of the Weigh Bar is the primary reason for this success.
The Weigh Bar has proven itself over the past 20 years to be one of the world’s most robust weight transducers manufactured today with over 500,000 installations world-wide.
The IP67 Weigh Bar design provides inherent strength and overload protection, while also providing accuracy and high reliability. A significant contributor for this is the positioning of the gauges on the outside of the Weigh Bar. More robust than a shear beam load cell for a given output – a shear beam load cell will reach its peak fatigue point much sooner than a Weigh Bar.
Error Reduction
The unique design of the Weigh Bar allows simple calculations to be made by the indicator, eliminating several types of errors:
• End Loading – When an end load is applied to the Weigh Bar, it is subjected to a uniform compressive strain throughout its length – all sensors detect the same strain. • Torsion Effects – When torque is applied to the Weigh Bar, a uniform torsional shear strain is developed through the length of the bar – both sensors detect the same strain. • Side Loading – When a side load is applied to the Weigh Bar, it acts as a beam, but at a 90-degree angle. When this occurs, the neutral axis of the beam (the point in the beam where neither tension or compression occur) falls directly under the center of the strain gauges. No apparent strain is seen by the gauges. • Vibration –The fine grain structure of aircraft quality steel is resistant to vibration fatigue and induced error. The strain gauges and adhesive used are also vibration and fatigue proven.
Load Cells – The Avery Weigh-Tronix Weigh Bar® Weight Sensor
The exclusive Avery Weigh-Tronix Weigh Bar® is an extremely rugged, highly reliable, load sensing device. Over several decades, the Weigh Bar® has built a reputation for precision, reliability and durability that no other load cell can match.
Weigh Bar – Reduced cost of ownership
Precision machined from aircraft quality, alloy steel, the Weigh Bar® offers excellent repeatability and long-term durability, reducing cost of ownership and need for load cell replacement.
Rugged Weight Sensors
With up to ten times more steel content than shear beams or compression cells, it absorbs impact to minimize peak forces and is virtually fatigue-proof. The Weigh Bar® is proven to resist electrical surges and is protected by a limited warranty that includes coverage against lightning damage.
Accurate Weigh Bar
The sensor’s design automatically cancels the effects of side loading, end loading and twisting, resulting in quick, accurate readings which are achieved regardless of temperature change, vibration, and shock loads on the scale.
Sealed “Load Cell”
The standard alloy steel Weigh Bar® is well protected against harsh environments by an exclusive 5-layer, sealing process. For the most challenging locations hermetically sealed stainless steel weigh bars are available.
A lot of customers are curious about this question… how long should a truck scale last? Or perhaps it’s phrased like this… how do I know when my truck scale needs to be replaced?
The vast majority of truck scales are located outside. This means the scales have the hot sun blazing down on them all summer (every year). Then, they have the piles of snow on them in the winter (every year). In between all the hot and cold extremes, they have all the rain that you typically see fairly often.
So, with all the weather conditions, that means a truck scale must be able to withstand all the environmental challenges while working reliably and accurately…. For years and years! And, be able to handle 80,000 lb vehicles everyday!
So, how long can I expect my truck scale to last?
That’s a really good question and it’s a question that has a variety of answers.
Depending on the environment and application, most truck scale owners can typically expect a truck scale to last anywhere from 15-30 years.
If your location consistently has over 250 trucks a day going over the scale (or you project it will eventually have that kind of truck traffic) then you will need to choose a truck scale built for that kind of traffic. Choosing an “economy” or standard duty truck scale in that situation may be cost effective now… but will most likely lead you to have a shorter truck scale life and force you into looking for scale replacements or weighbridge repairs sooner than you would prefer.
Sometimes spending an extra few thousand dollars up front will allow you to purchase a heavier duty “HD” scale that will last you significantly longer than the “SD” model. What’s an extra few thousand dollars when you average it out over twenty-five or thirty years of use? Especially if the extra cost helps you gain an extra five or ten years of scale use?
Can I Repair My Truck Scale Instead of Buying a New One?
This is a good question and a common question that a lot of people ask when they have an old truck scale. In most cases, the answer is yes. Depending on the age of the truck scale and severity of the issues, repairing a truck scale can certainly work and be a cost savings.
However, once a truck scale has been in service for over 20 years or so… repairs may not be the best choice. Often you will hear people refer to the scale repairs as “band-aids”. We understand what they’re referring to, but the truth is that truck scale repairs on a 20+ year old scale weighbridge are just that, repairs…
A “band-aid” is supposed to heal your wound and help you get back to 100%. A “band-aid” on a 30 year old truck scale is not going to “heal” the scale. It is simply designed to get a few more years out of the scale before the scale will need to be replaced.
Unfortunately, truck scales that have been repaired often don’t last as long as you would like. One of the reasons is simply the age of the steel and the components. Often the areas that were repaired may be ok after the repair, but then the other areas that were doing ok before the repair, are now starting to fail.
When you think of a truck scale overhaul, the Truck Scale components can usually be replaced… things like load cells, junction boxes, summing boards, etc…, but the core weighbridge construction and integrity are sometimes challenging to rebuild in a cost effective & timely manner…. especially in a scale that’s 25 or 30 years old… or older.
It’s also important to look at the actual repair costs. Sure it can be overwhelming when you see a $80,000 quote for a new truck scale. However, if you attempt to repair and put “band-aids” on a 25 year old truck scale, how much money is that going to cost? Between materials and labor, we’ve seen these repair costs rise above $3000. Plus there is down time where the scale can’t be used.
And even after the scale is repaired, there really is no guarantee or warranty that the scale is going to last X number of additional years. So, in this example, you could spend several thousand dollars on scale repairs that may get you a few more years of service…. or, that $3000 could be used to help pay for a new truck scale.
Planning for Buying a Replacement Truck Scale on Your Terms
Here is one other scenario that we would like you to think about. Let’s say you have a 25 year old truck scale. It has some weighbridge issues and probably should be replaced. But, you and the scale company talk and decide that some weighbridge repairs could likely be made that might give the scale a little more life. Keep in mind at the same time this talk is taking place, new truck scales are readily available with a short 1 to 2 week lead time for fast delivery.
Well, the truck scale repairs take place and it turns out that you did in fact get an extra year of use out of the scale. Unfortunately, the scale now has more weighbridge issues and repairs will likely not make much sense at this point. And, as often happens, the scale failure has just happened right in the middle of your busiest time of the year! And, now it looks like the lead time on truck scales is closer to 14 weeks and there is a 8% steel surcharge now in place.
This scenario that we just mentioned above is all to real and can very well take place. Sometimes if your scale has lasted for two or three decades, it can be a smart move on your part to setup the replacement purchase on your watch (before the scale actually “breaks”). Maybe you talk with your scale company and decide the next time there is an incentive offered, you’re ready to purchase. This can be a wise decision because we all know that no one wants to be in a situation with a broken scale that must be replaced and then be facing extended downtime and a 14 week lead time before your scale can ship.
There are a variety of options in the truck scale market today and, to the casual observer, initial acquisition price may be the only differentiator. However, manufacturers promising great bargains are able to do so only because they’ve cut corners at some stage of the process—design, materials, components, finish or all of the above. While the price may seem attractive now, the eventual failure of a lower quality truck scale could mean a higher total cost of ownership from extensive downtime, increased maintenance costs, lost revenue and premature replacement.
One other note to mention on the subject of money would be taxes and leasing. This article is not going to be in depth on either of those subjects but if you purchase a new truck scale there can be tax advantages (see IRS section 179). We also have leasing programs which can make it easier to afford a larger purchase like a truck scale.
One other thing we wanted to mention on this subject is the overall trend for truck scale pricing. Generally speaking, the price for new truck scales is not going to get any less expensive in 2021 and beyond. In fact, at the time of this article in early 2021, we have received word from at least (3) truck scale manufacturers that there will likely be surcharges very shortly due to steel prices. (So if you’re in the market for a new scale, it might be time to act now!)
2023 UPDATE: Throughout 2022 and 2023 we have seen multiple price increases and lead times from certain truck scale manufacturers that were in excess of 40 weeks!
Believe it or not, the goal of this article is not to be completely gloom & doom about repairing a truck scale weighbridge. There are certainly situations where a truck scale overhaul makes sense. Most of the time, it makes more sense to upgrade components and less sense to try and do major weighbridge structural repair.
However, if you’re in the market for refurbishing a truck scale or purchasing a new truck scale… we encourage you to look at the entire picture and get a true understanding of the costs involved and the expected lifespan with each scenario. The fact is that many truck scale manufacturers are getting really good at building their truck scales to fit existing foundations. This can help to lower costs and lessen the down time when you’ll be without a scale.
Truck scales are important to the daily operations of the facilities that use them. That means that selecting a truck scale is an important decision. Whatever scale you choose (or have chosen), will likely be your scale of choice for possibly two or three decades! Often, a little extra thought or cost up front, can pay off down the road with a durable truck scale that can provide decades of service with proper scale maintenance.
If you have questions or would like to obtain a truck scale quote, please complete our RFQ form on our website or you can call our heavy capacity scales team at (919) 776-7737.
#1 IMMUNITY TO LIGHTNING DAMAGE Unlike other load cell technologies including both digital and analog strain gauge load cells, hydraulic load cells are immune to damage resulting from lightning strikes or other electrical surges. Hydraulic load cells have neither strain gauges nor wiring like other load cell technologies thus making them unaffected by lightning strikes; one of the most common reasons for load cell failure.
#2 IMMUNITY TO WATER DAMAGE Hydraulic load cells are constructed using stainless steel components welded together then pressure tested to ensure there are no leaks. Keeping the hydraulic fluid inside the load cell also keeps water out. Hydraulic load cells will operate when continuously submerged in water for an extended period.
#3 OPERATES OVER A WIDE RANGE OF TEMPERATURES Hydraulic load cells are capable of operating over a wide range of temperatures. Using proprietary grades of aircraft hydraulic fluid, hydraulic load cells can and do operate at temperatures of –60 degrees C (-76 degrees F). A number of hydraulic vehicle scales are located across Canada.
#4 HYDRAULIC LOAD CELLS NOT SINGLE SOURCE COMPONENTS Unlike digital load cells, hydraulic load cells are currently available from at least two sources. Because there is no standard protocol for digital load cell outputs, you cannot replace a digital load cell with another digital load cell from a different manufacturer. Each manufacturer of digital load cells have their own proprietary output for the cell that works only with their weight indicators and other digital load cells.
#5 CAN OFFER SAME ADVANTAGES OF A DIGITAL LOAD CELL One advantage of a digital load cell is its ability to display weight data from each load cell in a multiple load cell scale (like a vehicle scale). Digital load cell systems can also alert the scale operator or service technician of a potential problem before the scale weights are affected. Hydraulic load cell systems are available with load cell system controllers that perform the same functions as found in digital load cell systems. These controllers digitize each hydraulic load cell output independently allowing the operator or technician to view the outputs of each load cell. Further, software is included to alert the operator when an excessive shift in the no-load output of one or more cells is detected prior to affecting the accuracy of the scale. Automatic calibration can be another feature of hydraulic load cell systems provided with a load cell controller.
#6 MEETS THE SAME LEGAL & METROLOGY PERFORMANCE STANDARDS The hydraulic load cells available in today’s scales have been thoroughly evaluated and have been found to be in compliance with NIST Handbook 44 requirements for Class IIIL multiple load cells with 10,000 divisions, just like their digital counterparts.
#7 HYDRAULIC LOAD CELLS HAVE A LONG HISTORY OF USE Hydraulic load cells have a long history of being used in scales; much longer than either the strain gauge load cell or digital load cell. They have not been as popular as the less expensive strain gauge versions of the load cell but, when the costs of ownership including cell damage, the hydraulic load cell is clearly less expensive to own.
#8 HYDRAULIC LOAD CELLS COME WITH A LIFETIME WARRANTY Most manufacturers of hydraulic load cells offer a lifetime warranty on their load cells against damage from voltage surges (lightning) and water damage; the two most common reasons for failure of strain gauge and digital load cells.
#9 SAFE FOR OPERATION IN THE MOST HAZARDOUS AREAS Because hydraulic load cells contain no electrical circuitry, there is no source of ignition when used in an explosive atmosphere. Hydraulic load cells are regularly used in hazardous areas where explosive materials are present. Fuel or other flammable materials leaking from a vehicle and collecting in the scale pit cannot be ignited by hydraulic load cells making them a safer alternative than strain gauge or digital load cell.
#10 HYDRAULIC CELLS OFFER LOWEST POSSIBLE MAINTENANCE COST A lifetime warranty on impervious, non-conductive environmentally-sealed stainless steel hydraulic load cell that are waterproof, shockproof, explosion-proof, and resistant to both caustic and corrosive environments means we are extremely confident in Cardinal hydraulic load cells.
Lightning strikes are one of the most common difficulties that can affect a truck scale. SmartCell® digital load cells provide superior protection that protects against electrical uncertainties.
• Truck scales, due to their composition and size, are a magnet for attracting lightning. Many times, these scales are placed in an outdoor area that is exposed to the elements. The main front of protection against lightning strikes and power surges lies in the junction box. Unfortunately, if the junction box is compromised it can cause damage to the whole load cell weighing system. One or more of the load cells can be damaged in a traditional load cell arrangement, which can come at a great cost.
• The gas discharging tubes that divert excess voltage from lightning and power surges are normally placed inside the summing box of analog load cell systems. Cardinal’s SmartCell® digital load cells have the apparatus of discharging excess voltage placed in each load cell. This ability for each load cell to individually protect itself provides another line of protection for the whole load cell system. If a lightning strike or power surge happens, one load cell has the capability of preventing damaging surges from passing onto other load cells.
• Unfortunately, lightning strikes and power surges are commonplace. These occurrences have the potential to wreak havoc on truck scale electronics. Luckily, Cardinal’s SmartCell® digital load cells can protect individual load cells and the entire load cell system from excessive damage caused by freak electrical incidents.
• If you’ve experienced reoccurring problems with damaged load cells and repairs caused by lightning and power surges, SmartCell® digital load cells can help protect your truck scale electronics against severe damage.
Replacing the SmartCell® load cell is incredibly simple. Most importantly, it is a very fast procedure that gets your scale back to work in rapid time.
• Ease of use is also continued with installation or replacement of digital load cell (DLC) cards or 225D mainboards in the truck scale’s weight indicator. The 225D indicator can detect whether either option has been replaced using checksums and board identification numbers. The new DLC card or 225D mainboard will be reconfigured to the existing scale by the indicator acknowledging the new card and asking the user to verify if it is new. This simple reconfiguration process saves time and effort.
• One of the most important upgrades the SmartCell® digital load cell offers is the ability for truck scale dealers to change out the load cell in a matter of minutes. Normally, with analog load cells, dealers will have to check, replace, or pull a whole host of wires from the summing box when changing one out. Now, Cardinal’s digital load cells can be removed and replaced in as little as five minutes without any specialized equipment. It really is that short and simple!
• Electronic truck scales with analog load cells require many more moving parts. With an eight-cell system there are up to 100 wires that have to be prepared and terminated, up to 14 configuration jumpers to be set for proper operation, and sense lines must be utilized to regulate excitation voltage. This complicated wiring system lengthens time spent when trying to simply replace a load cell and calibrate it. This cumbersome process is no longer needed with the ARMOR® digital system.
• The ARMOR’s simple load cell connector design and the axis® frictionless centering system’s unique construction permit just a few steps for load cell replacement. After turning off power and jacking up the weighbridge a minimal amount, a single technician simply has to remove the dual load cell cables, remove two bolts that hold the cell to the weighbridge, and place a new load cell in its place. Next, after applying cleaner and Dielectric grease to the load cell cable connectors, the connectors are reconnected, and the load cell bolts are tightened. It’s just that simple—not another moment needs to be spared on time-consuming load cell replacements.
• If you have to spend large amounts of time dealing with wiring analog load cells, the SmartCell® digital load cell streamlines the tedious task of getting your new load cell in operation.
We offer Cardinal load cells which is the point of this article. We also offer various other brands that you likely have heard of like Artech, Tedea Huntleigh, Sensortronics, and Revere Transducers. However, we also have brands you might not know much about like Flintec load cells and Coti Global. Call us (919) 776-7737 or email us for complete information and availability.
