Why calibration matters (and why it’s easier than you think)
If you’re running on-board scales, calibration is what turns sensor readings into axle weights and GVW that you can trust. Do it once, do it right, and you’ll get consistent numbers that help you load faster, avoid tickets, and keep equipment inside legal limits. To calibrate Air-Weigh® on-board truck scales, the workflow is straightforward, takes very little downtime, and uses a process your team already knows—getting certified weights at an in-ground scale. Air-Weigh® provides model-specific user guides and videos; follow those, and you’ll be dialed in quickly.
Step-by-step overview
1) Install, power up, then plan your two weighments.
Calibration requires two certified readings for each axle group: an empty weight (tractor/trailer with no payload) and a heavy/full weight (the vehicle loaded). You’ll enter both sets of scale tickets into the in-cab display or companion app, and the system will align sensor output to those real numbers. Calibrate as soon as the system is installed and powered so you start with accurate readings from day one.
2) Use a certified, segmented in-ground scale.
Head to a certified in-ground platform (e.g., a truck stop or municipal facility). For best results, park on a flat, level surface with brakes released and airbags properly inflated when capturing or verifying readings; this removes suspension binding and gives the sensors a clean baseline.
3) Capture the empty weight.
Weigh the tractor (and trailer, if attached) with no load. Record the certified axle weights and GVW from the printout. Back at the truck, follow your model’s on-screen prompts to enter the empty values for each axle group.
4) Load to working weight and capture the heavy/full weight.
Load the vehicle as you normally would —ideally as close to maximum operating load as practical. Weigh again on the same certified in-ground scale and enter those heavy values into the scale. The larger the spread between empty and heavy, the more precisely the system can map sensor output to true on-ground weight (more on that below).
5) Verify on level ground.
After entering empty and heavy values, roll the vehicle gently to a stop on level ground, keep the wheels straight, and release the brakes for a few seconds. Compare the on-board readings to your certified ticket. If something looks off, recheck the entries and repeat the settle/verify step.
6) You’re set—no constant tinkering required.
Once calibrated, Air-Weigh systems hold their accuracy. Recalibration is only needed if you make changes that affect suspension characteristics (e.g., swap components, move sensors, or alter configuration).
How our on-board truck scales work
Air-Weigh® scales read axle group load through the suspension—two main approaches depending on your equipment:
- Air-ride suspensions: A pressure sensor taps the suspension’s air line. As load increases, air pressure rises to support it. The scale samples that pressure and converts it to axle group weight.
- Mechanical/spring suspensions: A deflection sensor mounts to the axle/suspension to measure tiny amounts of flex as the load changes. That sensor output is converted to weight in the same way.
Air-Weigh’s manuals specify performance by suspension type: typical on-ground accuracy is ±300 lb per axle group for air-ride and ±3% per axle group for spring/mechanical—assuming correct installation and calibration. That’s precise enough to load confidently and avoid the dance of multiple re-weighs.
Why two scale tickets? (and why a big “delta” helps)
Calibration is a simple line-fit problem: the scale needs two trustworthy points (empty and heavy) to map sensor output to true certified weight. Using a heavy weight that’s close to your maximum operating load increases the span between those two points, which sharpens the mapping and improves on-board scale accuracy across your working range. That’s why the manuals recommend using maximum vehicle loads for heavy calibration when possible.
Pro tips for best results
- Calibrate right after installation. You can’t trust raw sensor output until you’ve aligned it to certified scale readings. Do your empty and heavy entries as soon as practical so drivers benefit immediately.
- Choose the right place and setup. Use a certified, segmented in-ground scale. On both weighments and any verification checks, park level, keep wheels straight, and release the brakes so the suspension isn’t bound up.
- Go heavy on the heavy ticket. The bigger the gap between empty and heavy, the tighter the calibration across your typical payloads. When possible, perform the heavy weigh close to maximum.
- Fill the tanks for steer/drive calibration. Manuals recommend a full fuel tank when calibrating steer and drive axle groups to remove a variable.
- Let spring-ride installs settle before calibrating that axle group. If you just installed a deflection sensor on a mechanical suspension, run the vehicle for a short break-in (per your manual) so the system stabilizes before you capture the calibration points.
- Set the fifth wheel position first (if applicable). On certain configurations that calculate steer axle weight from a single drive-axle sensor, moving the fifth wheel after calibrating can affect readings. Set it where you run most often before calibration.
- Know when to re-calibrate. Re-calibrate if you change suspension components, relocate sensors, or notice a consistent offset after maintenance. Otherwise, you shouldn’t need to re-do it.
- Follow your model’s exact prompts. Menu labels and icons vary by model (LoadMaxx, LoadMaxx Plus/QuickLoad Plus, etc.). Keep the relevant user guide in the cab—or open it on a phone—and follow the on-screen steps.
Quick refresher: where to find the official steps and video
Air-Weigh maintains a one-stop page with the latest installation and calibration manuals for each product family. Bookmark it and match the guide to your model and suspension type.
If you’ve been putting off truck scale calibration because you expect complexity, Air-Weigh made it simple: two certified scale tickets, a few menu entries, and a quick verification on level ground. Calibrate right after installation, use a heavy ticket close to your max working load, and follow the model-specific prompts. You’ll lock in on-board scale accuracy that speeds up loading, reduces re-weighs, and helps you run legal. Start here: open the Air-Weigh calibration manuals, grab your empty and heavy tickets, and calibrate Air-Weigh on-board truck scales across the fleet so drivers have reliable numbers on the very next run.