English to French Other Engineering (general)

Hello everyone,

I don't understand the 'drop in bar' part...

This is the context (incubation machine):

Verify the machine is correctly sealed, and proper cure time has elapsed.
Twenty-four hours is usually adequate for most cure times.
If the machine is configured with a humidistat, it should be securely located in its fitting and projecting inside the machine so that the tip is clear of the fitting.
Make sure the doors are firmly closed and latched.
With the drop in bar installed, stand inside the machine and check the gasket seal around the entire door perimeter.

Many thanks for your help!