diff --git a/istsos/plugins/unit_con_post/retrievers/aiopg/observations.py b/istsos/plugins/unit_con_post/retrievers/aiopg/observations.py
index df76d92..57d8984 100644
--- a/istsos/plugins/unit_con_post/retrievers/aiopg/observations.py
+++ b/istsos/plugins/unit_con_post/retrievers/aiopg/observations.py
@@ -793,21 +793,25 @@ def __get_array(self, offerings, request):
                                         if qty=='':
                                             add=0
                                         convert_unit="""(%s::text||'%s')::unit + ('%s'::text||'%s')::unit@@'%s' """%(col, ConvertUnit, add, unit, To_unit)
+                                        conversion_uom=To_unit
                                     elif request.get_filter("operation")['type']=='sub':
                                         sub=qty
                                         if qty=='':
                                             sub=0
                                         convert_unit="""(%s::text||'%s')::unit - ('%s'::text||'%s')::unit@@'%s' """%(col, ConvertUnit, sub, unit, To_unit)
+                                        conversion_uom=To_unit
                                     elif request.get_filter("operation")['type']=='mul':
                                         mul=qty
                                         if qty=='':
                                             mul=1
                                         convert_unit="""(%s::text||'%s')::unit * '%s %s' ::unit@@'%s*%s' """%(col, ConvertUnit, mul, unit, To_unit, unit)
+                                        conversion_uom=""" %s*%s """%(To_unit,unit)
                                     elif request.get_filter("operation")['type']=='div':
                                         mul=qty
                                         if qty=='':
                                             mul=1
                                         convert_unit="""(%s::text||'%s')::unit / '%s %s' ::unit@@'%s/%s' """%(col, ConvertUnit, mul, unit, To_unit, unit)
+                                        conversion_uom=""" %s/%s """%(To_unit,unit)
                         else:
                             if 'qty' in request.get_filter("operation"):
                                 qty=request.get_filter("operation")['qty']
@@ -817,23 +821,28 @@ def __get_array(self, offerings, request):
                                         if qty=='':
                                             add=0
                                         convert_unit="""(%s::text||'%s')::unit + ('%s'::text||'%s')::unit@@'%s' """%(col, ConvertUnit, add, ConvertUnit, To_unit)
+                                        conversion_uom=To_unit
                                     elif request.get_filter("operation")['type']=='sub':
                                         sub=qty
                                         if qty=='':
                                             sub=0
                                         convert_unit="""(%s::text||'%s')::unit - ('%s'::text||'%s')::unit@@'%s' """%(col, ConvertUnit, sub, ConvertUnit, To_unit)
+                                        conversion_uom=To_unit
                                     elif request.get_filter("operation")['type']=='mul':
                                         mul=qty
                                         if qty=='':
                                             mul=1
                                         convert_unit="""(%s::text||'%s')::unit * '%s %s' ::unit@@'%s*%s' """%(col, ConvertUnit, mul, ConvertUnit, To_unit, To_unit)
+                                        conversion_uom=""" %s*%s """%(To_unit,To_unit)
                                     elif request.get_filter("operation")['type']=='div':
                                         mul=qty
                                         if qty=='':
                                             mul=1
                                         convert_unit="""(%s::text||'%s')::unit / '%s %s' ::unit@@'%s/%s' """%(col, ConvertUnit, mul, ConvertUnit, To_unit, To_unit)
+                                        conversion_uom=""" %s/%s """%(To_unit,To_unit)
                     else:
                         convert_unit="""(%s::text||'%s')::unit@@'%s' """%(col, ConvertUnit, To_unit)
+                        conversion_uom=To_unit
                     cols[
                         columns.index(col)
                     ] = unionColumns[columns.index(col)].replace(
@@ -851,21 +860,25 @@ def __get_array(self, offerings, request):
                                     if qty=='':
                                         add=0
                                     convert_unit="""(%s::text||'%s')::unit + ('%s'::text||'%s')::unit@@'%s' """%(col, ConvertUnit, add, unit, ConvertUnit)
+                                    conversion_uom=ConvertUnit
                                 elif request.get_filter("operation")['type']=='sub':
                                     sub=qty
                                     if qty=='':
                                         sub=0
                                     convert_unit="""(%s::text||'%s')::unit - ('%s'::text||'%s')::unit@@'%s' """%(col, ConvertUnit, sub, unit, ConvertUnit)
+                                    conversion_uom=ConvertUnit
                                 elif request.get_filter("operation")['type']=='mul':
                                     mul=qty
                                     if qty=='':
                                         mul=1
                                     convert_unit="""(%s::text||'%s')::unit * '%s %s' ::unit@@'%s*%s' """%(col, ConvertUnit, mul, unit, ConvertUnit, unit)
+                                    conversion_uom=""" %s*%s """%(ConvertUnit,unit)
                                 elif request.get_filter("operation")['type']=='div':
                                     mul=qty
                                     if qty=='':
                                         mul=1
                                     convert_unit="""(%s::text||'%s')::unit / '%s %s' ::unit@@'%s/%s' """%(col, ConvertUnit, mul, unit, ConvertUnit, unit)
+                                    conversion_uom=""" %s/%s """%(ConvertUnit,unit)
                     cols[
                         columns.index(col)
                     ] = unionColumns[columns.index(col)].replace(
@@ -880,6 +893,7 @@ def __get_array(self, offerings, request):
                         col
                     )
 
+
             # print('Print col in observations 1')
             # print(cols)
             # print(off_cols)