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Slide CaliperS 

HoW to reAd A stArrett 50-dIvIsIon vernIer cAlIper GAGe

GRADUATED IN INCHES AND MILLIMETERS (DIRECT READING) MIllIMeter reAdInG

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

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