Note when the load cell selection
A structure and the choice of the form
Choose what kind of structure in the form of the load cell. Mainly depends on the structure and use of weighing the environmental conditions. To make a low profile weighing apparatus, generally should be used in the cantilever and the spoke sensor. Highly strict requirements on the shape, you can pillar sensor. In addition, the weighing instrument to use the environment is very humid, a lot of dust, you should select the sealed form of good; explosion hazards, you should make use of intrinsically safe sensors; elevated weighing system, you should consider safety and overload protection; used in high temperature environment, you should use a water cooling jacket of the load cell; in the alpine region, you should consider the use of the sensor of the heating device. In the form of selection, a factor to be considered are: maintenance convenience or cost. Once the weighing system has gone wrong, can be very smooth, very quick access to repair the device. If you can not do the form of a note to select enough suitable.
Two. Range selection
Weighing systems that value the closer the rated capacity of the sensor, its weighing accuracy, the higher. However, when in actual use because of the scale body weight, tare weight and vibration, shock, partial load, and thus limit the amount of the weighing system for the selection of sensors principles are very different. As a general rule, you can: * single-sensor static weighing systems: the fixed load (scales, containers, etc.) + change in load (load) required weighing ≤ selection of X70% of the rated load of the sensor. * Multi-sensor static weighing system: a fixed load (scale, container, etc.) + change in load (load) required weighing ≤ choice of sensor rated load X with the sensor number of X70%. 70 percent of the coefficient is to consider the vibration, shock, partial load factors increase.
Should be noted that: First, select the sensors have the rated capacity to try to meet the manufacturer's standard product line, value, otherwise, use non-standard products, not only expensive, but after the damage is difficult to substitution. Second, in the same weighing system does not allow selection of the rated capacity of different sensors. Otherwise, the system can not work properly. Furthermore, the so-called variable load (need to weigh the load) is the real load added to the sensor from the scale platform to the process of force between the sensor value is passed, the multiplier and the decay of institutions (such as leverage in the system), should consider its impact.
Three precision select (accurately, we selected)
The choice of the level of accuracy of the weighing sensor. To be able to meet the requirements of the weighing system accuracy level, as long as they can meet this requirement can be. 2500 indexing sensor can meet the requirements, do not use 3000 points. In a weighing system used a few of the same form the the same rated capacity of the sensor in parallel, the error Δ. Are: Δ = Δ/n1/2 The (2-12) where: Δ: a single sensor error; n: number of sensors. In addition, electronic weighing systems are generally composed of three parts: they are a load cell, weighing display and mechanical structure. When the system's tolerance to constitute the main part of the load cell, as a non-automatic weighing error (Δ) can normally only achieve 0.7 the ratio of components. According to this, since is not difficult to required sensor accuracy to make a choice.
Fourth, the special requirements of non-standard type
In some of the weighing system, there may be some special requirements, such hope that the elastic deformation of the load cell, which can allow small scale units in the sink when weighing, making the trucks at the driving track scale into and exit out of the scale platform to reduce the shock and vibration. In addition, constitute a dynamic weighing system, are bound to consider the natural frequency of the load cell is able to meet the requirements of dynamic measurement. These parameters in the general introduction of the product is not listed. To understand these technical parameters, they should consult the manufacturer, in order to avoid mistakes.
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