At what two points must an analog survey meter be calibrated on each scale?

Calibration of an analog survey meter is crucial for ensuring accurate readings across its operational range. The correct two calibration points are typically established at 33% and 66% of the meter's scale.

Calibrating at these points allows for a reliable assessment of the meter's linearity and accuracy throughout its range. The selection of 33% and 66% provides a balanced approach; it ensures that the meter is checked at both lower and upper portions of its scale, which are typically where the readings may show variations or potential inaccuracies.

By focusing on these specific points, the calibration process can identify and correct any non-linear behaviors of the meter that might not be evident when only calibrating at the extremes (such as 0% and 100%). This practice contributes to overall reliability in detecting radiation levels accurately, which is essential in various safety and monitoring practices in radiation safety protocols.