Setting the minimum output signal of a transmitter to proportionally represent the minimum input value is referred to as ________?

• A. zeroing the instrument
• B. calibrating the minimum
• C. offsetting
• D. nulling

Answer: (A)

The action being described is about establishing the baseline so that zero input corresponds to zero (or the minimum) output. That is zeroing the instrument. When you zero a transmitter, you set the zero point so the smallest input value maps to the smallest output value, ensuring the scale starts correctly and the relationship between input and output remains proportional across the range. If you used offsetting, you would add a fixed amount to all outputs, which would lift the bottom of the scale and distort that bottom-end proportionality. Nulling focuses on removing residual signals to achieve a true zero under a reference condition, not specifically setting the minimum input to the minimum output. Calibrating the minimum isn’t a standard term for this particular action; calibration generally involves adjusting zero and span to improve overall accuracy.