On-Board Scale System Configuration (Simplified)
Hardware: The weighing sensor is usually either load cell- or transducer-based and both typically use strain gages at its core. The difference is that load cells are primary force measurement devices where the load path goes through the cell, thus they are very accurate. Secondary transducers are sensors that attach directly to existing structural parts of the truck (axles, walking beams, etc.) to measure small deflections in that part that is carrying the load.
Electronics and Firmware: The electronic components include the readout and processor of the system and any wiring that attaches to the hardware. Within is an algorithm that processes the raw weights and filters out weight inaccuracies coming from the hardware. Getting accurate weights with the inherent pounding and vibrations of a garbage truck is where robust electronics with a well-written algorithm can make it (or break it) for an acceptable on-board scale system.
Software: Software features vary a lot from one scale provider to the next. When weights are gathered, do we want to automatically obtain the gross weight, or attach an individual pickup weight to a customer’s name, address and location? Does the software allow for automatic processing of data, or is the driver having to get involved to make decisions based on manual weight readings? What is the user interface and how easy is it to retrieve the processed data?
Some scale suppliers have great hardware but lackluster algorithms to filter out the weight errors that occur in mobile weighing. Some software companies approach the market with powerful data gathering, processing and integration, but with a complete lack of consideration to robust and repeatable weighing hardware. The fact is, to make an on-board scale system great, there has to be a good balance of accurate hardware, solid electronics and a desired level of software.
Not only are the manufactures on the hook for making systems reliable, but on-board scales also “don’t work” because a lack of vision casting from the hauling company’s C-level management as to what the objectives are for the investment. The purchasing decision is frequently pushed down the management chain. Many times the cheapest systems are purchased without much forethought to the overall company strategy and to the dedication required to make the systems work properly day in and day out. Buying cheap is a sure bet to keep within budget, but could be a disaster when trying implement.
Often when an upper manager does ask about how the scale program is working, only after the on-board scale systems have been purchased, the response is “the scales don’t work.” That’s when the maintenance manager shrugs his shoulders and explains, “Hey, I’m just trying to keep trucks on the road and get the garbage off the street, scales are the least on my worries.” Okay, argument over.
Success in Matching the Right System to the Right Task
In all fairness to the maintenance and operations team at any hauling company, frustrations bubble up when someone on staff has to become the “on-board scale expert”, especially when no one mentioned upfront this would be the case. Scale calibration and maintenance can be time consuming. Often scales are either not working after a short time in the field or they lose accuracy due to a lack of ongoing calibration. This is true especially for simple transducer based systems that monitor gross vehicle loads. The lower cost comes with a higher level of setup and re-calibration. Mind you, this can be an excellent choice for many haulers as they can be good systems to avoid costly overweight issues, it’s just that everyone must be on the same page from the beginning and understand the upkeep requirements.
When it comes to front loaders, using on-board scales is effective to gather information on weights (profitability) per pickup per account. Expecting the driver to write down, print, or confirm on a tablet the correct customer weight data is not optimal. Drivers already have many responsibilities and making information gathering an additional responsibility leads to incomplete and inaccurate data matching. Fortunately, this type of system has seen many improvements over the last several years to where some load cell based systems are very accurate, the data collection functions are fully automatic and the driver just drives. GPS matching to assign weights to accounts with cloud based reporting gives a full picture of profitability per account.
Whichever system is chosen to accomplish the job, whether it’s a system for monitoring total weight or it’s one for gathering individual commercial pick-up weights, on-board scales do work well. They key to success is matching the right system with the right task. The old saying about don’t “bring a knife to a gunfight” rings true; no one wants an on-board scale system that is not an adequate match for the anticipated challenge.
What’s the Scope?
There’s no disputing that on-board scales provide many benefits to the haulers that use them. Some of the advantages include eliminating overweight fines and liability exposure, better load optimization, reduced fuel costs and increased revenues.
The difficulty is that there are many systems to choose from with different features and pricing structures. So a good way to get started with an on-board weighing program is to consider the five steps of the W.E.I.G.H. method:
W – Write out all related weight issues or concerns, and take an inventory of problem areas.
E – Evaluate all types of on-board scale technology to find the right solution for your application.
I – Invest in a test or ‘pilot’ program with one or more of the technologies available.
G – Gather test results, quantify cost/payback, and execute a program to meet operational goals.
H – Harvest the positive results for years to come.
Today more than ever, it’s imperative that all projects have a scope management plan. The key is a strict focus for upper management to define the desired outcome for implementing such a program. The more time spent on developing a scope, the higher likelihood for successful implementation.