Pentax PLP-601 Instruction Manual page 8

The instrument should be stored in the carrying case and packed with
cushioning material and handled with care as 'Fragile' .
Check the 'check and adjustment of the datumpoint' of page 35 in this
manual and be sure to check to see if error exists before the instrument
is used. After the instrument has been stored a long time or it has
suffered an impact or vibration, be sure to check to see if trouble exists
before use. If any trouble exists, adjust or have it repaired.
8