Weigh Modules: Single-Ended Beam 21

14.0 Weigh Modules: Single-Ended Beam

14.1 IntroductionSingle-ended beam load cells offer many advantages when used in well-designed weigh modules. Modules using single-ended beam load cells have a low profile, and are generally self-checking. Load cell replacement is possible in most single-ended beam mount systems by raising the vessel only enough to remove pressure from the cell.

14.2 General Mounting Principles The mounting surface should be flat and level. The mounting block should be thick enough to

provide adequate threads for the mounting screws. The corner of the mounting surface (where the cell

canti levers out) must be hardened to prevent peening.

The mounting bolts should be at least grade five to prevent stretching or the possibility of breaking.

The load should be applied vertically through the center line of the load hole (the load may be applied from above, as illustrated in Figure 14-1, or may be hung from below).

The load introduction must provide flexibility to avoid the transmission of extraneous forces and to tolerate the unavoidable deflection of the load cell itself.

The mounting bolts should be torqued to specified values.

Figure 14-1.

14.3 Single-End Beam OrientationFigure 14-2 illustrates four different vessels and recommended mounting configurations for single-ended beam weigh modules. See the Section 14.9 on page 25 for special movement considerations that apply to this unique single-ended beam system.The vessels in the upper row, at right, illustrate a vertical cylindrical vessel. Note that the longitudinal axis through each load cell points towards the center of the vessel.This principle could also be used for the vessels in the lower row, if it were convenient to mount the cells in each corner with the longitudinal axis pointing toward the center. However, it may be more convenient, and is acceptable, to mount the cells as illustrated. As these cells are relatively immune to extraneous forces applied along the longitudinal axis of the cell, it should point in the direction of any prevalent side force (for example, on a roller conveyor, the load cells should point in the direction of travel).

Figure 14-2.

14.4 SURVIVOR 1700HE ModulesThese light- to- medium capacity modules use single-ended beam load cells in capacities from 5kg-250kg (11-550lb) and 500-5,000kg (1,100-11,00lb). The SURVIVOR 1700HE is ideally suited for light- to- medium capacity micro-ingredient batching and mixing in a variety of hostile environments, especially where moisture is present. This module provides superior corrosion resistance, moisture ingress and mechanical protection. The load cells are waterproof guaranteed and OIML C3 certified (20kg-5,000kg) to offer the ultimate in durability and accuracy.

Allowable Movement Figure 14-3 illustrates the 1700HE modules capability to handle movement. The load may be checked in one of two directions. This allows positioning in one of two orientations for proper checking.

Figure 14-3. SURVIVOR 1700HE