Interactive Vernier Callipers & Screw Gauge Simulator

APEX CLASS • IITJEE Experimental Physics Lab

Vernier Callipers & Screw Gauge Interactive Simulator

Master Least Count, Positive/Negative Zero Error, and Coincidence Readings with one tap!

🔍 Tap a Vernier Calliper Position to Inspect Scale Alignment:

1. No Zero Error (0.0 mm) 2. Positive Error (+0.3 mm) 3. Negative Error (-0.4 mm) 4. Measure Sphere (12.6 mm)

Least Count (LC) Formula

1 MSD – 1 VSD = 0.1 mm

1 mm – (9/10) mm = 0.01 cm

Main Scale Reading (MSR)

0.0 mm 0.0 mm (Jaws Closed) 0.0 mm (Jaws Closed) 12.0 mm (Mark before 0)

Read just left of Vernier Zero

Vernier Coincidence (VSR)

0 × 0.1 = 0.0 mm 3rd line → +0.3 mm 6th line → -(10-6)×0.1 = -0.4 mm 6th line → 6 × 0.1 = 0.6 mm

VSR = n × Least Count

Final Formula Result

Zero Error = 0.0 mm Correction = -0.3 mm Correction = +0.4 mm 12.0 + 0.6 = 12.6 mm

True = Observed – (±Zero Error)

🔩 Tap a Screw Gauge State to Inspect Circular Thimble Scale:

1. No Zero Error (0.00 mm) 2. Positive Error (+0.04 mm) 3. Negative Error (-0.03 mm) 4. Measure Wire (3.28 mm)

Least Count (LC)

Pitch / N = 0.01 mm

1.0 mm / 100 Divs = 0.001 cm

Linear / Pitch Scale (PSR)

0.0 mm 0.0 mm (Studs Touching) 0.0 mm (Studs Touching) 3.0 mm (Visible on Sleeve)

Last uncovered mark on sleeve

Circular Scale (CSR)

0 × 0.01 = 0.00 mm 4 × 0.01 = +0.04 mm -(100-97)×0.01 = -0.03 mm 28 × 0.01 = 0.28 mm

Line matching Reference Baseline

Final Screw Gauge Output

Zero Error = 0.00 mm Subtract 0.04 mm Add 0.03 mm 3.00 + 0.28 = 3.28 mm

True = PSR + CSR – (±Zero Error)