diff --git a/product.py b/product.py
index 787b5de..330f39a 100644
--- a/product.py
+++ b/product.py
@@ -227,11 +227,23 @@ class Template(metaclass=PoolMeta):
     @fields.depends('temperature')
     def default_temperature_uom(self):
         pool = Pool()
+        measurement = None
         Measurements = pool.get('product.uom')
-        measurement = Measurements.search(['name', '=', 'Celsius'])[0].id
+        if Measurements.search(['name', '=', 'Celsius']) != []:
+            measurement = Measurements.search(['name', '=', 'Celsius'])[0].id
 
         return measurement
 
+    @staticmethod
+    def default_frequency_uom():
+        pool = Pool()
+        measurement = None
+        Measurements = pool.get('product.uom')
+        if Measurements.search(['name', '=', 'Hertz']) != []:
+            measurement = Measurements.search(['name', '=', 'Hertz'])[0].id
+        
+        return measurement
+
     @staticmethod
     def default_frequency():
         return 0
@@ -253,10 +265,12 @@ class Template(metaclass=PoolMeta):
         return 0
 
     @staticmethod
-    def default_moisture_uom():
+    def default_voltageAC_uom():
         pool = Pool()
+        measurement = None
         Measurements = pool.get('product.uom')
-        measurement = Measurements.search(['name', '=', 'Relative Humedity'])[0].id
+        if Measurements.search(['name', '=', 'Volt']) != []:
+            measurement = Measurements.search(['name', '=', 'Volt'])[0].id
         
         return measurement
 
diff --git a/sale.py b/sale.py
index 808a382..e3b7ee6 100644
--- a/sale.py
+++ b/sale.py
@@ -184,11 +184,7 @@ class SaleLine(metaclass=PoolMeta):
             If(Eval('_parent_sale.sale_type') == 'maintenance',
                [('type', '=', 'service'),
                 ('maintenance_activity', '=', True)], []))
-        cls.product.domain.append(If(Eval('_parent_sale.sale_type') == 'equipments',
-               [('equipment', '=', True)], []))
-        cls.product.domain.append(If(Eval('_parent_sale.sale_type') == 'replaces',
-               [('replacement', '=', True)], []))
-        cls.quantity.states['readonly'] = Eval('_parent_sale.sale_type') == 'equipments'
+    
         
     def on_change_with_unit_digits(self, name=None):
         if self.unit:
diff --git a/view/maintenance_form.xml b/view/maintenance_form.xml
index 632d7e4..6148d94 100644
--- a/view/maintenance_form.xml
+++ b/view/maintenance_form.xml
@@ -16,7 +16,7 @@
     <field name="equipment"/>
     <label name="service_maintenance"/>
     <field name="service_maintenance"/>
-    <label name="equipment_calibrate" invisible="1"/>
+    <label name="equipment_calibrate"/>
     <field name="equipment_calibrate" invisible="1"/>    
     <newline/>
     <label name="description_activity"/>
diff --git a/view/maintenance_sample_form.xml b/view/maintenance_sample_form.xml
index d621da1..6c82658 100644
--- a/view/maintenance_sample_form.xml
+++ b/view/maintenance_sample_form.xml
@@ -13,7 +13,7 @@
     <field name="mistake"/>
     <label name="mistake_rate"/>
     <field name="mistake_rate"/>
-    <label name="product" invisible="1"/>
+    <label name="product"/>
     <field name="product" invisible="1"/>
     <label name="maintenance" />
     <field name="maintenance"/>