Mcleod Gauge with High Purity Mercury is a scientific vacuum measuring instrument used to measure very low pressures, down to 10-3 Torr or 0.001 mm.Hg. The design of a McLeod gauge is somewhat similar to a that of a mercury column manometer. Typically it is filled with mercury & the standard model measures vacuum from 10 mm.Hg. down to 10-3 mmHg. The Mcleod Gauge is the highest accuracy vacuum gauges available for measuring high vacuum. The Mcleod Gauge can be manually operated and the scale read visually. The Mcleod Gauge finds extensive use in applications like vacuum pumps, vacuum systems, vacuum evaporators, vacuum booster systems, pharma process, high vacuum furnaces, etc.