1. . 
A device used to measure pressure. Many different types of pressure gauges have been developed for use in well testing over the years. For bottomhole pressure measurements, these include helical bourdon tube gauges, strain gauges, quartz crystal gauges and surface readout gauges. All have their roles, and are still in use. Digital memory gauges are popular at the moment, since the data can be printed out or input directly into a computer for immediate use. Proper use of the data often requires specific knowledge of the possible idiosyncrasies of the particular gauge used in a test.