Distinguish between a passive and an active instrument transmitter.

Distinguish between a passive and an active instrument transmitter.

• A. Passive transmitters supply their own power and may provide higher-level output.
• B. Passive transmitters draw power from the loop and have no local power source.
• C. Passive transmitters are battery powered.
• D. Passive transmitters operate only with digital output.

Answer: (C)

Power source is what separates passive from active transmitters. In this context, a passive transmitter is described as having its own local power source, such as a battery, to run its sensing and electronics. That means it does not rely on the process loop to power the device. An active transmitter, by contrast, uses an external power supply to energize its electronics and can deliver stronger or more varied output, supporting higher-level signals or more demanding driving capability. The other statements describe alternatives (getting power from the loop or requiring only digital output) that don’t fit the definition used here.

Power source is what separates passive from active transmitters. In this context, a passive transmitter is described as having its own local power source, such as a battery, to run its sensing and electronics. That means it does not rely on the process loop to power the device. An active transmitter, by contrast, uses an external power supply to energize its electronics and can deliver stronger or more varied output, supporting higher-level signals or more demanding driving capability. The other statements describe alternatives (getting power from the loop or requiring only digital output) that don’t fit the definition used here.