However, increased accuracy is needed with shop-counter scales or scales used in filling machines. Here, scales contribute to quality assurance, for example, when ball bearingsare checked. Īccuracy class C3 load cells are widely used in machine construction as well. For this purpose, special building materials scales using accuracy class C3 load cells are available for mixing additives such as ash or sand. Load cells with relatively low accuracy classified D1 to C2 are sufficient for simple building materials scales used to weigh sand, cement or water.Īdding the right proportion of additives to building materials is essential. The chart provides an overview of typical applications, ranging from the lowest to the highest accuracy class. Load cells with different accuracy classes are required depending on the application. In practice, certain system accuracy parameters depend considerably on the application of use, physical load introduction to the transducer and disturbing factors such as Zener barriers and surge protection devices. A specific accuracy grade specifies an error envelope for certain parameters, such as linearity, hysteresis, temperature effects, creep, etc. Load cells are ranked, according to their overall performance capabilities, into differing accuracy classes or grades.
Precision classes explained: Which load cell for which application? Load cell comes in various weights depending on your application select the load cell weight specification, In this tutorial I have used 40Kg, Precision Grade C2 load cell. On HX711 board you will find E+, E-, A+, A- and B+, B- connections. Most Load cell have four wires red, black, green and white. Load Cell Connection diagram and its Pinout All controls to the HX711 are through the pins. There is no programming needed for the internal registers. On-chip poweron-reset circuitry simplifies digital interface initialization. It can be from an external clock source, a crystal, or the on-chip oscillator that does not require any external component. Onchip power supply regulator eliminates the need for an external supply regulator to provide analog power for the ADC and the sensor. Channel A can be programmed with a gain of 128 or 64, corresponding to a full-scale differential input voltage of ☒0mV or ±40mV respectively, when a 5V supply is connected to AVDD analog power supply pin.
The input multiplexer selects either Channel A or B differential input to the low-noise programmable gain amplifier (PGA). We are interfacing 40Kg load cell to the arduino using HX711 Load cell amplifier module. HX711 is a precision 24-bit analogto-digital converter (ADC) designed for weigh scales and industrial control applications to interface directly with a bridge sensor. In this arduino tutorial of HX711 Load Cell amplifier interface. HX711 Load Cell Amplifier, Weighing Scale Design