Weigh modules are subassemblies that incorporate a load cell and are designed to be mounted to tanks, trucks, bins, silos and other applications requiring the incorporation of an integrated weighing system. There are two basic types of weigh modules: compression and tension. Compression weigh modules are used to convert static loading applications such as tanks, or dynamic applications such as conveyors, into a scale. In tanks and other static structures, the weigh modules mount under the legs or supporting structure. Tension weigh modules convert a suspended tank or hopper into a scale. Mounting hardware ensures that only vertical load is measured, providing reliable weighing.
Product specifications for weigh modules include weighing application, capacity, resolution, and optional features. Bins, hoppers, tanks, and vehicles are examples of weighing applications. In-motion weigh modules are also available. Capacity is the maximum load that a scale or balance can measure without causing permanent damage to the device. Resolution refers to the smallest input or change in input that a weigh module can detect. In terms of features, weigh modules that are washdown-capable are designed to withstand a high-pressure washing or hosing. Weigh modules that are rated for hostile environments can withstand high or low temperatures, high humidity, chemical vapors, varying pressures, or shock and vibration.
Ratings and Certifications
Weigh modules differ in terms of ratings and certifications. IP66 weigh modules are sealed against dust and protected against pressurized jets of water. IP67 weigh modules are also sealed against dust, but provide protection against the effect of immersion between 15 cm and 1 m. NEMA 4 and NEMA 4x weigh modules are designed for indoor use. They meet requirements from the National Electrical Manufacturers Association (NEMA), a trade organization. Weigh modules that are NTEP-certified meet requirements from the National Type Evaluation Program. An NTEP Certificate of Conformance is issued by the National Conference on Weights and Measures (NCWM) upon successful completion of the evaluation and testing of a device. Weigh modules that are destined for sale in Europe should be WEEE-complaint. Waste Electrical and Electronics Equipment (WEEE) is a European Union (EU) directive that is designed to encourage the reuse, recycling and recovery of electrical and electronic equipment