The overall length of an empty two-piece capsule with its cap and body held together in the preliminary joining position before filling.
Also called: prelocked length; pre-locked capsule; prelock; Pre-lock length.
Why do empty capsules have a pre-lock position?
The preliminary joint holds the empty cap and body together during handling while allowing them to be opened for filling. Its design is intended to resist unwanted separation before use; the applicable preliminary length belongs to the particular shell design.
Pre-lock length is the overall dimension in that preliminary joined state. It is not the length of the cap alone, body alone or the fully locked filled capsule. The state must accompany the number.
For incoming-shell inspection, note whether the capsule remains in its supplied pre-lock state or has been separated and rejoined. Compare that state with its matching dimension, rather than a final-lock specification.
No. Length is a geometric measurement; pre-lock force describes resistance to separation. One length value is neither a force result nor a machine vacuum requirement.
Keep the opening-force result with the shell design, joining state and measurement method. A length reading cannot supply that force.