Tag: Current Loop

Resistance temperature sensor (RTD, resistive temperature device)  comes in NTC (negative temperature coefficient) and PTC (positive temperature coefficient) forms. A schematic diagram below show a signal conditioner circuit for such thermometer. This sensor conditioning circuit works in current mode (current loop) and the amplifier inside gives a current output that is  inversely proportional with the sensor’s resistance. This temperature transmitter […]

Current loop analog data transmission is used in industrial environment because of its robustness (good noise immunity), while providing wiring fault detection (short and broken wiring) with a simple mechanism by detecting out range current level. In 4-20mA current loop standard, the valid signal should be in the range of 4 to 20mA. Zero ampere current would indicate broken wiring, […]