Casella CEL CEL-63X - Manual (Page 68)

CEL-63x Environmental & Occupational Noise Meter
68 Casella CEL
7 Care and maintenance
Use a clean, slightly damp cloth to wipe the outside of the CEL-63x
instrument. Do not use abrasive, caustic or solvent materials to clean
the instrument.
Check the condition of the battery compartment when you fit batteries
to the instrument. Check for signs of corrosion and arrange any repairs
necessary.
Remove the batteries from the instrument if it will not be used for a long
period of time (more than one month).
Do not allow the instrument to become wet, or to be exposed to extreme
levels of dust, heat or cold.