Hyetometrograph is a specialized instrument used to measure rainfall over a specific area. However, in case you need some synonyms for the word, here are a few options. Pluviograph or "rain gauge" are other instruments that measure the amount of precipitation. Another synonym is the "rain gauge recorder," which records the amount of rainfall over a certain time period. Hyetograph, or "rainfall intensity recorder," charts the amount of rainfall over a given time, providing a more detailed view of rainfall activity. The term "precipitation recorder" can also be used to describe any device that records rainfall or other forms of precipitation. Regardless of the term used, they all contribute to a better understanding of climate and environmental changes.