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Appendix B Product Performance
B.1 External Output
1.1 Sensitivity 1V/mV,Tolerance:±5% or 0.5V/mV.
1.2 Impedance of External Output ≤100Ω.
1.3 Output short circuit shall not damage the ECG machine.
B.2 External DC signal Input
2.1 Sensitivity 10mm/V. Tolerance:±5%
2.2 Input Impedance ≥100kΩ
2.3 Input Impedance Attenuation. By Paralleling impedance of 4700PF capacitor and 620KΩ is
connected to each lead electrode. When achieving the specified value, the impedance should be near
to 2.5MΩ, each uniform resistance should be no less than 600 kΩ.
2.4 Input circuit current: all input circuit currency should be less than 0.1uA
2.5 Calibration Voltage:1mV, tolerance±5%
2.6 Sensitivity
2.6.1 Sensitivity control: At least three grade: 5, 10, 20mm/mV. Tolerance±5% by shifting
2.6.2 Anti-polarization Voltage : Applying ±300mV DC polarization Voltage, the tolerance of
sensitivity is ±5%
2.6.3 Minimum testing signal: Testing the energy of deviated sine signal of 10Hz、20μV (summit)
2.7 Noise Level
By paralleling impedance of 0.047μF capacitor and 51kΩ resistance which is connected between
input terminal and neutral electrode. Within the frequency range of regulation 4.2.10. The noise
level should be no more than 15μV(peak to peak value)
2.8 Anti-interference
2.8.1 The CMRR of each lead should be no less than 89db
2.8.2 ECG represents 10V rejection of common mode signal on patient, according to picture 5
simulation test , each lead is connected with simulation electrode --- Skin none-balance
impedance( paralleling impedance of 51kΩ resistance and 0.047μF capacitor) . The recording