Interactive precision measurement trainer — 0–120 mm — LC = 0.02 mm (50 divisions)
A Vernier height gauge is a precision measuring instrument used to measure the height of a workpiece from a reference surface (usually a surface plate or granite table). With a 0.02 mm least count and a 50-division vernier scale, this instrument is widely used in quality control, toolroom work, and precision engineering training.
Step 1 — Place on surface plate: The height gauge base sits on a precision surface plate, providing the reference plane. Step 2 — Main Scale Reading (MSR): Read the last whole millimetre mark below the vernier zero line on the main scale. Step 3 — Vernier Scale Reading (VSR): Find which vernier graduation coincides with a main scale line. Count that division number. Step 4 — Total Reading (TR): Apply TR = MSR + (VSR × LC) where LC = 0.02 mm.
If the main scale shows 47 mm (MSR = 47) and the 18th vernier division aligns with a main scale line (VSR = 18), then: TR = 47 + (18 × 0.02) = 47 + 0.36 = 47.36 mm.
Key parts: base (sits on surface plate), vertical beam/column (carries the main scale), sliding carriage (carries the vernier scale and scriber arm), scriber/measuring jaw (the actual measuring tip), locking screw (clamps carriage at reading), and fine adjustment knob (for precise positioning).
The vernier scale has 50 divisions that span 49 main scale divisions. One vernier division = 49/50 mm = 0.98 mm. The difference between 1 main scale division (1 mm) and 1 vernier division (0.98 mm) = 0.02 mm — this is the least count. When the nth vernier division coincides with a main scale line, the measurement is MSR + n × 0.02 mm.
This tool is ideal for TVET and engineering diploma students, toolroom apprentices, quality control technicians, and anyone preparing for metrology assessments or practical competency tests in precision measurement.