Over the last decade or so it has become popular to utilize a “relief header” in the ammonia refrigeration process. And in more recent years, the practice of installing an ammonia detector in this relief header has become very popular. Here are some random thoughts about these detectors that employers need to think through when considering their installation. Bottom line: The installation of the lone detector entails a bit more than just doing the MOC “paperwork” and installing the detector. Here is a breakdown of what we should have in place if we have a detector in our relief header: