UOM for companies with inventory in liquid form

Summary: Currently, WMS has all the items which are stored in Units UOM as Primary UOM. My question is what if company has to store items in liquid form or if vendors sends items in different UOM. How to make sure that all kind of UOM are stored in WMS and not just units?

Content (please ensure you mask any confidential information): What can be done to achieve this? Currently WMS takes all items as units only but how to bifurcate liquid and solid uom i.e. differentiate area and volume uom? We have UOM and UOM class defined in the system but how to ensure that wms takes all the uom other than cases,packs, units.