Mobile weighing
May 1st 2006 There is increasing pressure on all businesses to maximise the productivity of their operations and to meet the ever-growing list of health and safety regulations. The introduction of mobile weighing technologies can offer a number of benefits to operators of pallet trucks and fork lifts explains Zeb Lawton*, director of Euroscales Traditionally, weighing of palletised loads has been performed by static weighing scales and weighbridges, where a load is moved to the scales, weighed and then moved again to its destination. With the increasing size of warehouses and production plants, unnecessary movement of loads has a cost in terms of time, fuel and machinery wear and tear. Static weighing facilities can also be sources of bottlenecks, which introduce further delays, and are often located externally, so that goods are subject to the elements.
You also need to consider the employer's liability with regard to health and safety issues of moving excessive loads, both in terms of overloading and unbalancing handling machinery and racking, and causing injury to operators moving overweight loads manually. This latter point has been responsible for a significant movement from entirely manual pallet trucks to electrically assisted versions to ensure that productivity doesn't drop due to H&S limits on load capacity.
Taking all these things into account, you can see an excellent case for introducing weighing onto pallet trucks and fork lifts, with immediate indication of the weight of the load to the operator.
On-truck weighing technology
Weighing systems fit broadly into 3 categories: hydraulic, carriage mounted and fork mounted, with attendant advantages and disadvantages, and you need to balance cost, accuracy, ease of installation and robustness against reductions in usable load weight and physical constraints such as movement of balance point and minimum load height due to the dimensions and weight of the weighing units.
Probably more important is the additional functionality which can be introduced once a weight is captured, taking it way beyond basic weight displays: - On-board printing of tickets and labels
- Visual and audible warnings of overload conditions
- Automatic component counting
- Cumulative and incremental weight displays for recipe-based vessel charging
- Logging of weight, time and operator input data for later analysis and audit trail
In addition, the incorporation of computer functions into the weight display units provides means of communicating a whole range of information to the operator, such as picking lists and work schedules, and linking to hand-held data terminals and barcode readers to transfer weight or product count information, generally via a wire (RS232) or short range line of sight infra-red link.
Wireless technolgies
Using the facilities provided on the truck itself, information is likely to be exchanged with the company's stock control computer infrequently, typically at the end of each shift. Since many companies operate just-in-time stock control systems, collecting data at the end of a shift means that trigger stock levels must be set higher to allow for and entire shift's usage.
To overcome this, wireless communication technologies are being introduced so that each truck can be in direct communication with a central system. This means that data on stock usage, movement and deliveries can be communicated in real-time and instructions can be passed back to the operator to respond immediately to new requirements. Wireless technologies also mean that such functions as printing can easily be performed remotely, and can be combined with information about deliveries and despatches held on the company's management information or production control systems.
Of increasing importance in this area is Bluetooth.
This is a wireless communications technology that many people come across in relation to wireless mobile telephone headsets, but its application is far wider and particularly relevant to data communications over short and medium distances. A key feature of Bluetooth is that its universality means that it is very affordable and many components are designed specifically to work with computers, and it is robust and secure.
Future capabilities will include the ability to communicate with RFID systems, and this is likely to be used, for example, to verify that the delivered weight of a pallet load is within a certain weight range, to identify thefts of pallet contents which is not apparent from visual inspection.
* Zeb Lawton is a director of the familyrun Euroscales, the Macclesfield based supplier and maintainer of a wide range of weighing products. These include complete weighing-enabled fork lifts, manual and electrically power pallet trucks and conversion kits to add weighing capability to existing units.
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