The most common and most likely answer to this crossword clue is the 9 letter word SCRAPYARD
I've seen this crossword clue in The Guardian
S
C
R
A
P
Y
A
R
D
Buddy explains!
The straight part
We know that "Call to use metric" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case call to use metric = scrapyard.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does SCRAPYARD mean?
SCRAPYARD noun- A junkyard, a place where scrap is stored, discarded or resold.