Which term describes mounting a transmitter below the bottom of a tank?

• A. Zero Elevation
• B. Cascade control
• C. Zero Suppression
• D. Relay 1

Answer: (C)

Mounting a transmitter below the bottom of a tank means the sensor sits under the liquid column and experiences the hydrostatic pressure from that liquid above it. That additional head would bias the reading, making the level appear higher than it actually is. To keep the output representing the true tank level, the transmitter’s zero is adjusted to offset that extra pressure—a process called zero suppression. This specifically accounts for the submergence by shifting the zero so the reading matches the real level. The other terms don’t describe this situation: zero elevation is just a height reference, cascade control is a two-loop control strategy, and a relay designation isn’t relevant here.