Hello,

Unit of Procurement OR Unit of Purchase??
if it is Unit of Purchase and Unit than You Can find one Module from Odoo Community (Odoo Apps)
Install it and then Go to Setting>Mass Editing>Mass Editing

Crate and add to select object(product.template) and field (uom_id, uom_po_id) and Click On Add Sidebar Button.

and save.

After Go to Product Tree-view select all and go to  Action>MassEditing(Product) and then one Wizard is open

then You can set as Unit.

Your all Product UOM and POM is Change as Unit from Foot.

Thank You.