When must a survey meter be recalibrated aside from the standard interval?

Recalibrating a survey meter after instrument servicing is essential because any modifications or repairs can alter the meter's performance or accuracy. During servicing, components may be replaced or adjusted, which can lead to changes in the calibration settings. Recalibration ensures that the survey meter provides accurate readings consistent with the established standards after any mechanical or electronic adjustments have been made.

Adjustments might affect sensitivity, response time, or other critical parameters that influence how the instrument measures radiation levels. Therefore, recalibrating after servicing is a key practice in maintaining the reliability and safety of radiation measurements.

Other scenarios, such as changing the battery or switching measuring units, do not necessarily require recalibration, as they might not impact the fundamental measurement capabilities of the device. Recalibration is specifically warranted in cases where the integrity of the measurement has potentially been compromised, making it vital to do so after servicing.