겨울철 수도계량기 동파 방지.

- http://blog.naver.com/PostView.nhn?blogId=boinsystem&logNo=220776806339

- http://blog.naver.com/PostView.nhn?blogId=yelimcc09&logNo=220855290484

- http://cafe.daum.net/ejutaek/Mhrl/5190?q=%B0%DC%BF%EF%C3%B6%20%BC%F6%B5%B5%B0%E8%B7%AE%B1%E2%BA%B8%BF%C2%B9%E6%B9%FD

- http://cafe.daum.net/noosuin/EccY/11?q=%B0%DC%BF%EF%C3%B6%20%BC%F6%B5%B5%B0%E8%B7%AE%B1%E2%BA%B8%BF%C2%B9%E6%B9%FD

- http://www.sudokwon.com/read.php3?aid=1480234278333696011