LECTURE: EKG Graph Paper
Overview
ECG paper: grid system
- 1 big box/square = 25 small boxes/squares
- 1 small box = 1 mm => 1 big box = 5 mm x 5 mm
Horizontal = time (s, ms)
- 1 mm (1 small box) = 0.04 s (40 ms)
- 5 mm (1 big box) = 0.2 s (200 ms)
- 5 big boxes = (0.2 s) x 5 = 1 s
Vertical = voltage (mm, mV)
- 1 mm (1 small box) = 0.1 mV
- 10 mm (2 big boxes) = 1 mV
Calibration:
- Standard: 10 mm (1 mV) high x 5 mm (0.2 s) wide; typical speed = 25 mm/s
- Half-standard: “stair-like” structure; ↓ voltage