diff --git a/apps/inm/serializers.py b/apps/inm/serializers.py
index 760fe0b0..3d97cacc 100644
--- a/apps/inm/serializers.py
+++ b/apps/inm/serializers.py
@@ -284,14 +284,17 @@ class MIOItemPurInTestSerializer(CustomModelSerializer):
     class Meta:
         model = MIOItem
         fields = ['id', 'test_date', 'test_user',
-                  'count_bag', 'weight_kgs', 'is_testok', 'test_note']
+                  'count_bag', 'count_sampling' 'weight_kgs', 'is_testok', 'test_note']
         extra_kwargs = {
             'test_date': {'required': True},
             'test_user': {'required': True}
         }
 
     def validate(self, attrs):
-        weight_kgs = attrs['weight_kgs']
-        attrs['weight_kgs'] = [float(i) for i in weight_kgs]
-        attrs['count_sampling'] = len(attrs['weight_kgs'])
+        if 'count_sampling' in attrs and attrs['count_sampling']:
+            pass
+        else:
+            weight_kgs = attrs['weight_kgs']
+            attrs['weight_kgs'] = [float(i) for i in weight_kgs]
+            attrs['count_sampling'] = len(attrs['weight_kgs'])
         return super().validate(attrs)