Zero Elevation refers to mounting the transmitter at which position relative to the tank bottom?

• A. Below the bottom
• B. At the bottom
• C. Above the bottom
• D. Inside the tank

Answer: (C)

Zero elevation is about where you fix the transmitter along the tank height to establish its reference point for measuring the liquid column. Mounting the transmitter above the tank bottom sets that reference higher up, so the device senses the hydrostatic pressure of the liquid column above it rather than dealing with bottom disturbances. This position reduces the effects of sludge, turbulence, and potential fouling at the very bottom, and keeps the impulse line and seals in a cleaner, more stable region. With the transmitter above the bottom, you obtain a stable zero (when the tank is empty) and a reliable span as the liquid level rises. Placing the sensor at or below the bottom introduces more fouling risk and measurement errors, and placing it inside the tank isn’t typical for this kind of level setup.