GRADUATED IN INCHES AND MILLIMETERS (DIRECT READING) Inch Reading • Refer to the lower bar graduations and the inch vernier plate. Inches are numbered in sequence over the full range of the bar. Every second graduation between the inch lines is numbered and equals .100". Each bar graduation is .050" • The vernier plate is divided into 50 parts, each representing .001". Every fifth line is numbered – 5, 10, 15, 20 … 45, 50 – for easy counting • To read the gage, first count how many inches and how many .050" lines lie between the zero line on the bar and the zero line on the vernier plate and add them • Then count the number of graduations on the vernier plate from its zero line to the line that coincides with a line on the bar. Multiply the number of vernier plate graduations you counted by .001" and add this figure to the number of inches and .050" lines you counted on the bar. This is your total reading Example In the photo, the vernier plate zero line is one inch (1.000") plus .100" beyond the zero line on the bar, or 1.100". The 9th graduation on the vernier plate coincides with a line on the bar (as indicated by stars). 9 x .001" (.009") is therefore added to the 1.100" bar reading, and the total reading is 1.109" Millimeter Reading • Refer to the upper bar graduations and millimeter vernier plate. Each bar graduation is 1.00mm. Every tenth graduation is numbered in sequence – 10mm, 20mm, 30mm, 40mm, etc. – over the full range of the bar. This provides for direct reading in millimeters • The vernier plate is divided into 50 parts, each representing 0.02mm. Every fifth line is numbered in sequence – 0.10mm, 0.20mm, 0.30mm … 0.80mm, 0.90mm – providing for direct reading in hundredths of a millimeter • To read the gage, first count how many millimeters lie between the zero line on the bar and the zero line on the vernier plate • Then find the graduation on the vernier plate that coincides with a line on the bar and note its value in hundredths of a millimeter.Add the vernier plate reading in hundredths of a millimeter to the number of millimeters you counted on the bar.This is your total reading Example In the photo, the vernier plate zero line is 28 millimeters beyond the zero line on the bar, and the 0.18mm graduation on the vernier plate coincides with a line on the bar (as indicated by stars). 0.18 millimeters is therefore added to the 28mm bar reading, and the total reading is 28.18 millimeters How to Read a St arrett 50-Division Vernier Caliper Gage 102 S lide C alipers