![]() If multiple load cells are connected in parallel, then the total output will be the summed average of the outputs from the individual load cells. In practice this is not always easy to do, and it will depend on the overall resolution or accuracy required of your weighing system. This dead load will use up a portion of the load cell output, and as a result should be as low as possible compared to the “Live Load” (active weighing range). Full scale capacity takes into account the weight of any vessel or platform on the load cells, usually referred to as the “Dead Load”. This output is the full scale output from no load to full capacity load. With 5 volts excitation, the full scale output for your Hardy load cell will be anywhere from 0 Millivolts to a maximum 15 Millivolts. ![]() Hardy load sensors have outputs from 0.9 to 3 Milli Volts per volt (mV/V). The final choice of load cells for your system will be somewhat of a compromise based on the standard capacities of Hardy’s load sensors and your application requirements. With newer technology found in the HI4050, HI6300 sereis and HI6500 series this minimum has been expanded to 1:40,000. Strain gauge load cells should not be expected to work beyond a minimum stable/repeatable weight increment of 1/10,000th of the load point capacity. It is not possible for a typical weighing system with a total capacity of 80,000 pounds to weigh in increments of 1 pound (1/80,000). But if you require stable readings or a specific level of accuracy, you need to consult the accuracy specifications for that sensor.Before choosing load cells for a specific application, the user should verify it is possible to achieve sensible results from the planned weighing system. So when choosing a resolution you can have as many divisions as you want. There are many factors that influence the output signal (linearity, hysteresis, repeatability, temperature effects etc), all of which depend on how the sensor is used. It is important to determine accuracy, especially with pressure sensors. The resolution itself is derived from the electronic equipment that measures the signal from the sensor, ie a voltmeter. So what does this mean in relation to a sensor? Most sensors give an analogue signal output, which in theory has an infinite or limitless resolution. It is therefore very important to determine the accuracy of the string and the accuracy of your measuring device in order to establish the total accuracy and to choose a resolution that makes sense. Your ruler may have a very high resolution but if, for example, the string changes length due to temperature variation this will show up on the measuring device (ruler) as an error. Lastly, it is very important to differentiate between resolution and accuracy. And, similarly, if you want to measure something very small in size, you don’t use a ten-metre measuring tape. For example, if you want to measure the length of a bridge, you don’t arrive with a vernier gauge that can measure down to a hundredth of a millimetre. ![]() However, it is important to get the right relationship between what you are measuring and the measuring device. The resolution on the string itself is theoretically infinite or limitless. And the resolution of this measurement depends on the accuracy of the ruler used. The length of a piece of a string depends on what is used to measure it – in this case, a ruler. This leads us to the old question: “How long is a piece of string?”. So, for example, if you take a standard office ruler, the divisions are in millimetres and centimetres, and the best “resolution” is 1 millimetre. According to the dictionary, resolution is defined as the act or process of separating into parts.
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