Load cell

Traditionally, the load cell is a general term for load cell and load cell, and its measurement characteristics are evaluated by a single parameter. The old national standard considers "weighing" and "force measurement" two sensors with completely different application objects and use environmental conditions into one, without distinguishing between test and evaluation methods. The old national standard has a total of 21 indicators, all of which are tested at room temperature; and the largest error among the 6 indicators of non-linearity, hysteresis error, repeatability error, creep, additional error of zero temperature and additional error of rated output temperature is used to determine the scale The accuracy level of the heavy sensor is expressed as 0.02, 0.03, and 0.05 respectively.

A force sensor used on weighing instruments. It can convert the gravity acting on the measured object into a measurable output signal in a certain proportion. Taking into account the influence of gravitational acceleration and air buoyancy at different locations of use on the conversion, the performance indicators of the load cell mainly include linearity error, hysteresis error, repeatability error, creep, zero temperature characteristics and sensitivity temperature characteristics. In various weighing instruments and quality measurement systems, the integrated error is usually used to bring the accuracy of the integrated control sensor, and the integrated error band is linked with the error band of the weighing instrument (Figure 1) in order to select the weighing instrument corresponding to a certain accuracy sensor. The International Organization for Legal Metrology (OIML) stipulates that the error band δ of the sensor accounts for 70% of the error band Δ of the weighing instrument. The linearity error, hysteresis error of the load cell, and the error caused by the influence of temperature on the sensitivity within the specified temperature range, etc. The sum cannot exceed the error band δ. This allows the manufacturer to adjust the various components that make up the total measurement error to obtain the desired accuracy.

Advantages: insensitive to loading point changes, good anti-eccentric load performance, good inherent linearity, convenient installation, fixed and non-rotating load cell, low manufacturing cost.

Disadvantages: The center of gravity is high, the overload capacity is poor, and it is difficult for a large-scale load cell to reach a high accuracy level.