Change after_initialize to after_find.

lib/measurement.rb

@@ -6,8 +6,8 @@ def self.included(base)
   def measurement_convert(name, from, to)
     from  = from.call if from.is_a?(Proc)
     to    = to.call   if to.is_a?(Proc)
-    
-    self[name] = self[name].from(from).to(to).to_f.round(3) if !self[name].nil? && from != to
+
+    self[name] = self[name].from(from).to(to).to_f.round(3) if from != to
   end
 
   module ClassMethods
@@ -24,7 +24,7 @@ def measurement(*args, &block)
           measurement_convert(name, options[:database_unit], options[:model_unit])
         end
 
-        after_initialize do |record|
+        after_find do |record|
           measurement_convert(name, options[:database_unit], options[:model_unit])
         end
       end

measurement.gemspec

@@ -6,7 +6,7 @@ Gem::Specification.new do |s|
 
   s.required_rubygems_version = Gem::Requirement.new(">= 1.2") if s.respond_to? :required_rubygems_version=
   s.authors = ["Ronni Steen Rasmussen"]
-  s.date = "2012-03-13"
+  s.date = "2012-03-21"
   s.description = "Automaticly convert measurements units."
   s.email = "ronni.rasmussen@gmail.com"
   s.extra_rdoc_files = ["README.md", "lib/measurement.rb"]