A vacuum gauge is a pressure gauge used to measure pressures decreased when compared to the ambient atmospheric pressure, which happens to be set as being the zero issue, in detrimental values (As an illustration, −15 psig or −760 mmHg equals full vacuum). Most gauges measure pressure relative to atmospheric http://pressuregauge59258.blogkoo.com/top-latest-five-pressure-gauge-urban-news-29917273