Why Is My Load Cell Inaccurate? 11 Problems and Solutions for Troubleshooting Load Cells

Accurate load cells are critical to get the right mix. There are many different types of load cells for different processes, all of which can become inaccurate for different reasons. In this blog post, we’ll discuss a few of the ways your load cell may become inaccurate, what these problems look like when they occur, and how to troubleshoot load cell problems.

11 Problems and Solutions for Troubleshooting Load Cells

1. Total Combined Error

All measurement devices will have some degree of error that is not preventable. In load cells, this is shown through non-linearity and hysteresis. Since some level of error is unavoidable, there aren’t load cell troubleshooting strategies for this. However, this is acceptable as long as the error is less than the error tolerance of any ingredient. Additionally, non-linearity and hysteresis are less problematic in particular situations.

Non-linearity describes the weighing error over the entire load cell range. Smaller changes will create less error due to non-linearity, while a change from zero to maximum capacity will cause the greatest effect. Hysteresis is the difference in the results between increasing the load from zero and decreasing from maximum. Similar to non-linearity, error due to hysteresis is more noticeable when dealing with larger loads. So, when working with batching, this inevitable error is generally less of a problem compared to larger loading operations.

2. Temperature Changes

Dramatic temperature changes cause metal to warp. Traditional load cells are built using strain gauges, which are delicate metal pieces. Dramatic temperature changes will affect the function of the strain gauge, and therefore the load cell. If the load cell is exposed to cold nights and then hot, direct sunlight, or surrounding equipment heats up the area, this can cause inaccuracy. To troublehshoot this load cell problem, you might take temperature readings at different times, and shield the equipment from the sun if it causing dramatic temperature shifts.

3. Creep

If a load cell remains under pressure for a long period, it becomes susceptible to creep. This isn’t a problem in batching operations at two or three minute intervals, but load cells measuring storage silos or other containment units for extended periods will need to account for creep.

4. Load Cell Response

All load cells require a set time to return to zero before they can accurately measure a new load. If the process begins to refill the vessel before the load cell(s) return to zero, the measurement won’t be accurate within the error tolerance. Allow enough time between measurements for the load cells to stabilize and response time will not be an issue. To troubleshoot this load cell problem, test the load cell response upon installation and with calibration, to ensure it remains stable.

5. Balanced Load

The load must be properly balanced on the load cell, or the load cells must be arranged to accommodate for unbalanced loads. Where multiple load cells are used, they must be mounted so no other part of the vessel or container takes on a part of the load. For a sitting vessel, this generally means the load cells must be situated between the vessel and the floor. For a mounted load, bumpers and checkrods used to stabilize the load cannot also support its weight.

6. Vibration

Excessive vibration, usually from other nearby processes or sometimes from passing trucks or heavy equipment, can disrupt the reading. Troubleshooting this load cell problem might involve moving the source of the vibration or moving the load cells and attached equipment. Dampening devices such as layers of rubber or cork can also absorb the vibration. If the vibration is cyclical, it can also be electronically filtered out by a weight controller.

7. Windforce

Air currents exert force on a load cell that can disrupt the weight of the load alone. Usually, this is not enough to cause significant inaccuracy, but strong, consistent windforce can disrupt the reading. This might come from intense winds outdoors, or from strong air currents used to prevent dust buildup.

8. Noise

When the load cell transmits its electrical signal to the weight controller, interference, or noise, can disrupt it. Radio signals and electromagnetic signals both cause noise, which includes electrical currents, other data transmission signals, even strong wireless signals. Proper shielding around the load cell cables and grounding of the shield can prevent interference from noise. Using a capacitive digital load cell can also help to prevent signal loss due to noise. In a capacitive digital load cell, the signal is converted to digital locally within the load cell, so there is no loss of signal across the cable length or at bad connection point.

9. Moisture

Moisture can also inhibit the signal from the load cell to the weight controller. Moisture, perhaps from steam, excessive humidity, or equipment washing, most often enters the load cell through the cable entry area. Hermetic sealing will prevent moisture from damaging the load cell and internal components.

10. Signal Jitter

A number of factors can cause the weight signal from a load cell to “jitter;” moving unsteadily upward (or downward, as in a loss-of-weight feeder) instead of in a smooth line. The hopper’s or vessel’s movement while weighing, material entering the vessel unevenly, an agitator preventing sticking, or unshielded noise can all cause the signal to fluctuate. A weight controller averages the fluctuation and creates a smooth analog signal, then converts the signal to digital. However, if the weight controller isn’t working properly or isn’t installed properly, signal jitter will disrupt the measurement.

11. Damaged Load Cell Connections

Often, multiple load cells are used to measure a load. When these load cell signals are not combined and summed properly at the weighing instrument, it can cause noticeable error. This can occur due to faulty connections between the load cells and the instrument. Corrosion from acids or salts can cause connections to corrode, thereby disrupting the signal.

One of these load cell problems alone will probably not create a noticeable problem, unless it is extreme. However, several of them occurring at once can cause measurements to be noticeably inaccurate. Careful attention to the environment around the load cell and the equipment, as well as the installation and use of the load cell itself, can prevent many load cell problems.

Cattle Pro: The Cattle Feed Micro Machine Saving Time and Money

cattle pro

Finding the right cattle feed micro machine for your dry and liquid micro ingredient additives can save you time and money. However, it’s important to find a balance between price, ROI, maintenance costs, ease of use, and functionality. Understanding the challenges facing feedlots, APEC developed the Cattle Pro with flexibility, durability, and cost-savings in mind. The Cattle Pro enables feedlot owners to precisely add  the best combination of antibiotics and nutrients for optimal quality.

8 Benefits of the Cattle Pro Micro Ingredient Scale

cattle micro machine mixer 1. No Commitment, Better Prices

Many liquid and dry weighing machines for cattle come with an unspoken agreement; a long-term ingredient supplier’s  contract. The Cattle Pro does not have fine print. The Cattle Pro micro machine is suitable for any of the typical micro ingredients used in a feedlot, and is programmable for any amounts you specify. You can continue to purchase from any suppliers, so you are free to shop around for the best price.

Our Cattle Pro Micro Ingredient System means you no longer need to sign a contract with your micro ingredient distributor. It allows you to reduce costs by shopping for the micro ingredients without being locked into a contract. The Cattle Pro Microingredient System is fully accepted and compliant with government regulations.

Learn more about the Cattle Pro micro machine for dry and liquid micro ingredients »

2. Fewer Processes

The Cattle Pro allows you to add dry and wet micro ingredients in exact amounts.  The system delivers the ingredients as a slurry that is pumped directly to your feed mixer.  This means no more time-consuming separate weighing and adding of nutrients and antibiotics. The Cattle Pro also weighs ingredients in a fraction of the time compared to manual weighing. You and your staff can save time, energy, and manpower.

3. Faster, Easier, Safer

Weighing and adding micro ingredients by hand not only takes time, energy and extra staff, but it also introduces error. A moment’s distraction means feed is not properly formulated and cattle are exposed to nutrient deficiencies and the possibility of disease. The Cattle Pro eliminates this uncertainty with a pre-programmed, precise weighing system and automatic delivery into the feed mix. Liquid and dry ingredients are weighed and added exactly, every time, in a few quick minutes.

4. Lot and Ingredient Tracking

For organization and quality assurance, it’s important to know where your ingredients come from and where they go. The Cattle Pro can conduct barcode tracking on ingredients automatically, so you can see exactly what nutrients, antibiotics and other additives went into the feed. Lot tracking takes this visibility a step further, showing you where the feed went, and when it was used.  Every transaction is stamped with the exact time and date, so there is no guesswork involved.

5. Accurate Measurements Support ROI

Adding too many minerals or antibiotics means paying for extra you don’t need. Not adding enough means cattle don’t get the nutrients they need for optimal production or disease resistance. Exact feed measurements and mixing allow you to pinpoint the optimal amounts, and perfectly balance inputs and outputs.

6. Low Maintenance

Investing in an automated micro machine for cattle feed additives means weighing the costs against the benefits. Maintenance plays an important part here. The Cattle Pro is easy to clean and maintain, giving it a long life and minimal down-time. The flush hopper and conveyor can be separated from the machine, so it is easy to completely clean. The modular construction makes it easy to access any areas that require maintenance. Made from industrial-grade stainless steel with off-the-shelf components, it can easily be maintained.

7. Reduce Waste

The Cattle Pro automated cattle feed micro machine is completely enclosed.  This keeps the additives contained and eliminates housekeeping problems from water mist escaping from the machine.  The heavy duty construction and precision load sensors mean that you will have accurate results time after time. This also makes it more durable and less susceptible to jamming or environmental damage. Finally, the ingredient conveyor and water pump combination is designed for optimal efficiency, requiring less water than comparable models.

8. Start Right Away

Set-up is also an important consideration when investing in an automated cattle feed micro machine. It shouldn’t take a team of experts to get it up and running. The Cattle Pro is pre-wired and pre-plumbed, so the startup takes less time.  

The Cattle Pro simply makes cattle feed mixing easier. When you save time, money, and benefit from consistent feed quality, you can focus on growing your business. Learn more about the Cattle Pro micro machine  online or contact us for more information.