<field name="category_id" ref="product_uom_categ_kgm"/>
<field name="name">kg</field>
<field name="factor" eval="1"/>
+ <field name="rounding" eval="0.001"/>
</record>
<record id="product_uom_gram" model="product.uom">
<field name="category_id" ref="product_uom_categ_kgm"/>