Vernier height gauges

The above principles apply to the vernier height gauge, Fig. 6.9. In this case the beam, carrying the fixed scale, is attached to a heavy base. The vernier scale carries a jaw upon which various attachments can be clamped. It is most widely used with a chisel-pointed scribing blade for accurate marking out, as well as for checking... 

Vernier height gauge Large range on one instrument. Resolution of LCD model 0.01 mm... 

The barometer is perhaps the simplest pressure gauge and it is stili commonly found in laboratories to assess barometric pressure. It is one of the few instruments that measures absolute pressure. Before Toricelli, water columns of 10.3 m were necessary to study pressure. Toricelli invented the mercury barometer with a density 13.6 times that of water thus the column height is never much more than 0.9 m. The barometer is composed of a tube, a pool of mercury as well as a scale to measure distance and a vernier used to assess the exact position on the scale to a precision of 0.1 mm. 

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