For industrial process control instruments, analog 4–20mA current loops are commonly used for analog signaling, with 4mA representing the lowest end of the range and 20mA the highest. The key advantages of the current loop are that the accuracy of the signal is not affected by voltage drop in the interconnecting wiring, and that the loop can supply operating power to the device. Even if there is significant electrical resistance in the line, the current loop transmitter will maintain the proper current, up to its maximum voltage capability. Continue reading Arduino 4-20mAmp Current Loop Measurement →