Lever-type dial indicator (dial test indicator)Dial test indicator (lever type)

≡Standards, measuring range and accuracy

Standard

• JIS B 7533:2015 Lever-type dial gauges
• ISO 9493:2010 Dial test indicators (lever type)

^[1][2][3][4]

Measuring range

• byMaker
  • Mitutoyo TI-113HX (513-404-10H) 0.8 mm (graduation 0.01 mm)

^[6][9]1 source, for reference

Resolution / graduation

• General 0.01 / 0.002 / 0.001 mm (metric)
• Guide to stylus ball diameter 1 mm: very small features, 2 mm: general use, 3 mm: when you want stable readings on a rough surface

^[5][3]1 source, for reference

Accuracy (instrument error / maximum permissible error)

• Approach JIS B 7533:2015 specifies the forward-direction indication error over the full measuring range, the 10-division indication error, the 1-revolution indication error, return error, repeatability, and measuring force. The forward direction is the direction against the measuring force
• byMaker
  • Mitutoyo 513-404-10H (0.01 mm, 0.8 mm) 10 divisions 5 µm, full range 9 µm, return error 4 µm, repeatability 3 µm, measuring force 0.3 N or less

^[3][6]1 source, for reference

▦Types

◎Part names and functions

◷How to read the scale

1. Cosine correction: when the angle θ between the stylus and the measuring direction is large, multiply the reading by a correction factor (cos θ)Example: reading 0.002 mm, θ = 30° → 0.002 × 0.87 = 0.00174 mm (example from Mitutoyo E11003)^[3][10]
2. Correction factor table (Mitutoyo): 10° 0.98, 20° 0.94, 30° 0.86–0.87, 40° 0.76, 50° 0.64, 60° 0.50^[10][3]
3. Comparison reading from the zero point with graduation 0.01 mm and measuring range 0.8 mm (Mitutoyo's explanation has an example diagram)^[9]

✋Usage steps

1. Operation check: lightly move the stylus with a finger and check that the pointer follows smoothly and the return is not slow. Check that the stylus is securely fixed to the bearing^[9][4]
2. Check that the stem and the dovetail-groove stem are not loose (Teclock gives the stylus screw tightening torque as 1.5–2 kg·cm)^[9][4]
3. Mounting: secure it in a rigid holder, square to the front so it does not tilt^[9][10][5]
4. Contact point angle: set the contact point at a right angle to the measuring direction (the direction of displacement), i.e. parallel to the measured surface^[9][4][8][3]
5. Zero point: setting zero at the middle of the measuring range lets you read unexpected dimensions within range^[9]
6. Uses: runout of rotating parts, parallelism against a precision surface plate, comparison with a reference, centering on a lathe, setup on a milling machine, etc.^[9][5]

!Common measurement mistakes and countermeasures

✓Care, storage, inspection and calibration

Care and storage

• Wipe dirt off the contact point with a dry cloth or a cloth with a little alcohol. Do not oil it^[9][4]
• Clean the cover with a dry cloth or mild detergent only^[9][4]
• Do not disassemble or modify^[10][4]

Inspection and calibration

• JIS B 7533 method: hold it, set zero near the starting point, read the indication error every 10 divisions in the forward direction, move past the end point, then read in the return direction as well^[3]
• Mitutoyo inspects vertical, inclined and right-angle types with the dial face up, and horizontal types with the dial face upright^[3]

Cosine error lends itself to a diagram of angle versus correction factor. Sources disagree on the factor at 30°: 0.86 (E12024) and 0.87 (E11003) (a difference in how cos 30° ≈ 0.866 is rounded).

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