4-20 mA Current Scaling
Convert a 4-to-20 mA current signal into the corresponding process variable, PV = LRV + (I − 4)/16 · (URV − LRV), the universal standard of industrial instrumentation. The 4 mA represents 0% of the range and 20 mA, 100%; the 'live zero' at 4 mA distinguishes a null reading from a broken cable (0 mA). Enter the measured current and the lower and upper range values.
Result
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Escala de corrente 4-20 mA
O sinal de 4 a 20 mA é a língua franca da instrumentação industrial há décadas. Um transmissor converte a variável de processo (temperatura, pressão, nível) numa corrente proporcional: 4 mA = 0% da faixa, 20 mA = 100%. A conversão de volta é PV = LRV + (I − 4)/16·(URV − LRV). Por que corrente e não tensão? Porque a corrente não se degrada ao longo de cabos longos (a mesma corrente passa por todo o laço), é imune a quedas de tensão e ruído. E por que começar em 4 mA e não em 0? O 'zero vivo': se a leitura cair a 0 mA, sabe-se que o cabo rompeu ou o instrumento falhou — distinguindo 'medição zero' de 'sem sinal'. Informe a corrente medida e os limites da faixa.
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The results provided by this tool are for general informational and educational purposes only and do not constitute professional, financial, medical, legal, tax or accounting advice. Always confirm important decisions with a qualified professional and official sources.