The accuracy of the data that is stored by the VIMS Truck Payload System will be within “± 5% on 95% of the payloads”. There are some conditions that could affect the accuracy of the VIMS truck payload system weighing process. Some of these conditions are listed here:
- A truck is loaded on a sloped surface that is greater than “5 percent”. Accuracy will become progressively worse as the slope becomes greater.
- A suspension cylinder is not properly charged. The suspension cylinders may not cause an event even if the charge is incorrect. However, the “weighing accuracy” will be affected.
Note: Refer to the Special Instruction, SEHS9411-01, "Suspension Cylinder Servicing" for information on servicing the suspension cylinders.
- Pushing down on the load with the “loading tool” during the “weighing process” (packing the load)
- Moving the truck more than a distance of “
.16 km (0.1 miles) ” in any direction between “loader passes” - Actuating the "body raise lever" during loading
- A failure to have the VIMS Truck Payload System calibrated after replacing system components.
- A failure to have the VIMS Truck Payload System calibrated after any “substantial changes” to the empty weight of the truck.
- Using a conveyor or a “continuous feed system” for loading
- A truck leaves the loading site before cylinder pressures have stabilized and the final weight has been displayed. This will cause the VIMS Truck Payload System to estimate the payload weight instead of weighing the payload.
- Failures that are detected by VIMS may cause the payload weight to become inaccurate. These failed events will be shown in the “VIMS event list”.
Note: TPS accuracy is not affected by placing the first loader pass into the truck body before the truck comes to a complete stop under the loading tool. This relates to the 9.3X or later classes of on board software. The truck can be repositioned during loading. The truck must not travel a distance that is greater than
The smallest increment of the real time clock measurements are 1 second. The recorded times and dates of the real time clock will aid in identifying the causes of any unusual cycle data.
The accuracy of the “distance measurement” will depend on the actual effective rolling radius of the tires. The VIMS Truck Payload System does not distinguish between tires of different sizes, manufacturers or tread depth. The VIMS Truck Payload System distance measurements are calculated on the average tire size for each model of truck. Distance measurements are recorded to the nearest