All guidance systems require a floor flatness of no more than a 1:400 gradual rate of change in any direction over a distance of 2 meters. If you have an existing premises that you think may not meet this criteria, it doesn't mean you can't use a guidance system, but there may be some rectification works necessary. It is the MHE manufacturer's responsibility to specify what floor flatness is required to operate their equipment safely & at its optimum, but it is the end users responsibility to ensure that these flatness specifications are adhered to.
Wire guidance involves cutting a 10-12mm deep x 3mm wide path in the concrete slab, inserting an electrical wire to form a loop/circuit, sealing over the laid wire & then connecting the wire ends to a line driver which is generally supplied with the VNA equipment.
Flooring Considerations
With a new premises, it is just a matter of relaying to the property developer the required floor flatness, also known as the Fmin rating & it becomes part of the building process. However, if you have or are moving into an existing premises, the process may require expertise in measuring & possible rectification works. To confirm your facilities floor suitability, arrange for a Surveyor to visit your premises & conduct a profile report. This report will detail the rises & falls across the area where the VNA equipment will be operated.
BEWARE: The one process you never consider is channel grinding aisles. This involves grinding only the wheel paths, which is usually 3 channels, the drive wheel in the center & the load wheels on the outside. When installing wire guidance it is imperative that the wire remains a consistent depth, to minimise any signal strength variations. When you channel grind a floor & then install wire guidance, the saw used to cut the wire guidance path remains on the existing surface whilst the blade is aligned to the center of the aisle. Obviously in areas where center wheel grinding has occured, the depth of cut will be shallower. Where excessive grinding is required (3mm+), the blade then needs to be adjusted deeper, as you are coming out of the ground down area, the blade is then cutting too deep. You will also need to consider the cost of the floor make good should you plan on selling or moving, as the floor will now have the same profile as a sheet of corrugated iron. Anyone offering this service in conjunction with wire guidance, has no idea about the intricacy of wire guidance, so make sure you use logic & common sense if anyone offers this service, as it will only cause MHE down time & hidden costs. |