Protect them from bumps and falls. They may be top-heavy if the detector is in a cradle on top of the instrument. Broken scintillation detectors may cost several hundred dollars to replace. Component failure is relatively rare. Keep all instrument manuals, calibration reports, and related materials for reference in the event of instrument failure.
Many instruments work best if the humidity is low.
High humidity may cause the meter to read much higher than background even when no radiation source is present. A small container or porous bag of silica gel desiccant placed inside the instrument's case may prevent problems. Inspect color-indicating silica gel frequently for color change. Calibration ORS provides calibration services for survey meters. Calibrate your meters at least annually and following each repair.