Measurement accuracy of an ECG machine to the voltage reading generated by the electrode attaching body and was arrested later in describing the ECG strip.
Calibration is commonly used calibration 10mm/mV.
This means every little box 10mm (2 large boxes) vertical grid / voltage (Y axis) representing 1mV. Meaning:
1 large box = 1 / 2 = 0.5 mV
1 small box = 1 / 10 = 0.1 mV
Calibration 20mm/mV
This means that each small box 20mm (4 large boxes) vertical grid / voltage (Y axis) representing 1mV. Meaning:
1 large box = 1 / 4 = 0.25 mV
1 small box = 1 / 20 = 0.05 mV
Usually used when the results of the ECG recordings obtained was too small so illegible or difficult to read.
Occur in people who are very obese.
Calibration 5mm / mV
This means every 5mm small box (1 large box) vertical grid / voltage (Y axis) representing 1mV. Meaning:
1 large box = 1 / 1 = 1 mV
1 small box = 1 / 5 = 0.2 mV
Usually used when the results of the ECG recordings obtained too large so illegible or difficult to read because the images overlap on 12 leads recording. Recordings of the most overlap is R or S wave in precordial leads.
Occur in people with abnormal atrial or ventricular hypertrophy
