Railcar scales are an expensive, long-term investment — this is a commitment for 20 years or more. Below are the principles by which offers are worth comparing, and the questionnaire we ask you to fill in before we prepare a commercial offer.
The scales must hold a certificate of entry in the register of measuring instruments. Only that document guarantees that the equipment matches its stated specifications and is approved for commercial accounting. The technical specifications of the scales can be checked in the Type Description (an appendix to the certificate), to make sure what is being offered to you is what is actually on the register.
Installation must fit within the agreed track closure window — as a rule, three days.
The scales must not get in the way of track maintenance. For a foundation-free design, it must be possible to tamp crushed-stone ballast under the scales.
Digital data transmission not only removes the effect of electromagnetic interference and carries the signal over long distances, but also allows diagnosing the load cells, controlling the weighing platforms and getting the weight breakdown of a railcar by bogie and by side.
Good scales do not lose accuracy when the ground settles within the limits of railway track maintenance standards.
Every load cell must have its own channel — that is the only way to determine the lateral offset of the centre of gravity. Uneven loading is dangerous and can lead to derailment.
The ideal design of scales is one that not only ensures weighing accuracy, but also eliminates free travel of the platforms and impacts as railcars move over them.
Equipment built into a railway track operates in a high-hazard area. Experience is the guarantee that the scales will serve for more than one season.
These details determine the design of the scales, the number of platforms and the make-up of the hardware-and-software system.