Canon QL19 - Manual (Page 10)

I
MERCURY BATTERY LOADINGl
Load the mercury battery in a separate
envelope into the battery compartment.
Since the mercury battery powers the CdS
meter, unless the battery is in position the
meter will not function.
1 Insert coin into groove of battery cover
and turn to the left to remove.
2. Face the central contact of the mercury
battery inwards and insert, then screw
the cover back in.
When inserting, do not confuse the 0 0.
In case of reverse insertion, the meter will
not function properly.
* For mercury battery, the National M-IP