ECG calibration
Also calledstandardization · calibration pulse · cal mark · standardization mark · calibration signal
Definition
The reference settings that make ECG amplitudes and intervals comparable between recordings. The standard gain is 10 mm/mV: a 1 mV signal moves the trace 10 mm (two large boxes), so each 1 mm small box equals 0.1 mV. The standard paper speed is 25 mm/s: each 1 mm small box equals 0.04 s and each 5 mm large box 0.20 s. A calibration signal on the tracing lets the reader confirm the gain; on analog machines the 1 mV (10 mm) pattern is checked on each tracing, while digital machines verify it automatically.
Sources
- Meek S, Morris F. ABC of clinical electrocardiography. Introduction. I: Leads, rate, rhythm, and cardiac axis. BMJ. 2002;324(7334):415-418. doi.org/10.1136/bmj.324.7334.415
- Kligfield P, Gettes LS, Bailey JJ, et al. Recommendations for the standardization and interpretation of the electrocardiogram: part I: the electrocardiogram and its technology. Circulation. 2007;115(10):1306-1324. doi.org/10.1161/CIRCULATIONAHA.106.180200
- Samesima N, God EG, Kruse JCL, et al. Brazilian Society of Cardiology guidelines on the analysis and issuance of electrocardiographic reports - 2022. Arq Bras Cardiol. 2022;119(4):638-680. doi.org/10.36660/abc.20220623
Last reviewed 2 October 2026. Every definition in the EKG Dictionary cites the guideline, consensus statement or original paper it comes from.