What is the main advantage of using a voltage sensing device over a current sensing device for analog inputs?

• A. Higher precision.
• B. Faster response time.
• C. Lower cost.
• D. Easier wiring.

Answer: (B)

The main idea is that how quickly a signal is captured depends on the path it takes to reach the ADC. A voltage input lets the field signal be read directly by the analog-to-digital converter, usually with fewer delay-causing elements, so changes in the signal appear in the measurement faster. A current loop, on the other hand, requires a transmitter to drive current through a loop and then through a shunt in the input, adding extra circuit dynamics, capacitance, and a settling time that can slow the response to quick changes. Because of these extra steps and the loop’s inherent dynamics, voltage sensing typically offers a faster response time than current sensing. While precision, cost, or wiring can vary with the setup, the standout advantage for fast updates is the quicker response of voltage inputs.