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88 • ROCK products • May 2015 www.rockproducts.com EQUIPMENT & TECHNOLOGY MAINTENANCE & WEAR PARTS for some service companies to skip this important step. All too often, weights may be condemned and un-certifiable. This is why it is important to verify with your service provider that their weights have been certified. Here's a tip for conducting this test weight verification: All test weights have a stamp provided by the govern- ing state weights and measures entity. It is also common practice, among com- panies that value quality, to request a copy of the test weight certification from the scale service provider. Weight serial numbers will be present on the certifications, and the customer can verify these numbers against the seri- al numbers on the test weights used by the service company (see figure 1). Make Sure Testing Process Is Thorough To test a weighing device properly, one must first determine the length of the platform and the total number of sec- tions along that length. A scale section is determined by the presence of a load point, which is sim- ply the location of a load sensor (also known as a load cell or strain gauge). Load points are where weight is trans- ferred from the load to the scale and where scale accuracy is maintained. It is of critical importance, and mandat- ed by the testing procedure of National Institute of Standards and Technology's (NIST) Handbook 44, that the accu- racy of load points are maintained, so as weight is applied, it is transferred evenly. If a load point or section fails a strain test, then it must be calibrated to conform to requirements by making a mechanical or electronic adjustment. The load point is not calibrated to a cer- tified weight, but rather calibrated to ensure that all sections weigh exactly the same or within government speci- fications outlined in Handbook 44 and/ or issued by a state-sanctioned weights and measures organization. Incorporate Visual Inspection and Repairs Like vehicle owners, scale owners must perform regular maintenance. In addi- tion to the critical calibration compo- nent, a thorough scale maintenance program must include visual inspec- tion, followed by any necessary repairs. A good service company should conduct a free visual inspection and have the ability to perform these minor repairs while on-site for the maintenance visit. The visual inspection should include these key items: • Scale condition. • Regulatory conformance issues. • Any damages. • Safety. • Clearance. • Grounding. • Mud/debris build-up • Use issues. • Corrosion. • Electrical conditions. A reputable service company will care- fully inspect the scale, looking at these and other items, and offer solutions to any issues discovered. Most scale owners understand that it is better to repair and address issues when they are small, rather than wait until they are big and expensive. Thorough Reporting A good scale maintenance program will provide thorough reporting. Each maintenance inspection should include a written report documenting test results, and including both before and after calibration, as well as a summary of finding and recommendations. Russ Desilets is a regional director at Fairbanks Scales. Figure 1