Aggregate producers should prioritize the five following maintenance tasks for their truck scales in the second half of the year to ensure optimal performance and longevity.
The five
1. Regular cleaning. Keep your truck scale free of debris, dirt and other obstructions that could affect measurement accuracy.
Every scale’s weighing, in general, will be affected if something external is touching the platform. With truck scales, debris compiling between the scale bridge and end or pit walls – or underneath the scale and building up around the foundation – can become problematic.
Daily visual inspections are recommended to ensure the platform is clean. Check beneath the weighbridge for debris buildup between the foundation and weighbridge, as well as between the weighbridge and end or pit walls. Check all load cells, too, and clear debris around them.
Additionally, wash out around the base and end walls, as needed, to keep the scale platform free and clear of obstructions.
Consider, too, that some truck scales utilize axis load cell stands that position the load cells up high within the load cell pocket. In these cases, debris buildup around the base won’t affect weighing performance, and there are no moving parts below the scale deck.
Truck scales doing 150 or more weighments per day might require calibration multiple times a year.
2. Mechanical checks. Inspect components such as load cells, junction boxes and cables for signs of wear, damage or corrosion. Regular checks can help identify issues before they lead to significant problems.
Many truck scales include rodent protection that encloses load cell cables in metal conduit and features metal trays above and below the load cell pocket to prevent rodents from chewing on wires. Check the ground connections to make sure the cables are tight and free of corrosion. This will help to protect your scale from lightning strikes, which could cause serious electrical damage.
Also, some truck scales do not require junction boxes because the load cells daisy-chain to one another and the home run cable runs from the last load cell to the weight indicator in the scale house. This type of digital scale can provide individual load cell diagnostics.
3. External check rod adjustments. Some truck scales require external check rods to limit the movement of the scale platform to ensure accurate weight readings from the load cells. Check rods help to maintain the alignment of the platform and prevent excessive side-to-side or end-to-end movement that could affect the accuracy of the measurements.
Some truck scales employ axis frictionless load cell stands that provide gravity-driven dynamic centering, because the entire scale platform rests on durable ball suspension that restrains deck movement and vibration. With these scales, no external checks or maintenance is required.
4. Weatherproofing. Seasonal weather changes can affect the performance of truck scales, so ensure that all weatherproofing measures are in good condition to protect scales from rain, snow and temperature fluctuations.
Remember, though, that some load cells are completely encapsulated inside the load cell body to protect them internally and externally against moisture ingress, which is the most common factor to affect load cells in truck scales.
5. Scale calibrations. High-traffic truck scales doing 150 or more weighments per day might require calibration multiple times a year due to the high volume of use. It is often recommended to have them calibrated at least two to three times per year by an authorized scale service company using a test weight truck or cart.
For lower volume use, an annual calibration is typically sufficient. But environmental factors and specific operational demands might necessitate more frequent calibration.
Additionally, any time a scale component is changed such as a load cell, junction box or check rod adjustment, a scale calibration will be necessary using a test truck or cart.
Consider, too, that, some truck scales do not have junction boxes or check rods, which are common points of failure that can cause downtime and costly calibrations.
Final thought
By prioritizing these maintenance tasks, aggregate producers can ensure their truck scales remain accurate and reliable, minimizing downtime and maximizing productivity.
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