Allow the scale to hang freely from its support ring.
Fill the container with exactly 1000cc of clear water.
The slotted holes located near the top of each container are designed to initially retain slightly more than 1000 cc.
Using a file, carefully enlarge the bottom of the slotted holes until water begins to leak out. The container should now retain exactly 1000 cc.
Hang the container full of water on the scale hook.
Turn the zero adjustment screw located directly above the scale hook until the scale pointer is vertical, reading 1.000 on the dial outer ring.
The scale is now calibrated.