1) Dynamic input range: For a differential mode voltage with an
amplitude of 10mV (peak-to-valley) (when the gain is set to
5mm/mV) that is superimposed with a 300mV DC bias voltage
and changes at a rate of 125mV/s, the digital recorder should
have the ability to respond and display. The amplitude of the
time-varying output signal equivalent to the input should not
exceed 10% or 50uV, whichever is the maximum.
2) Input impedance Under the specified test signal (10Hz, 5mV
sinusoidal signal), the input impedance should be higher than
10M. This requirement shall also be met when a DC bias
voltage of ±300mVim is superimposed. (The steady-state output
amplitude must not be reduced by more than 6%).
3) Common mode rejection: For sinusoidal signals at the mains
frequency, the common mode rejection is at least 60dB, and for
signals twice the mains frequency, at least 45dB.
4) Gain accuracy: The output signal is equivalent to the input test
signal, and the maximum amplitude error is ±10%.
5) System noise: When all the input terminals are connected in
series to each patient electrode through a resistance-capaci
tance parallel network of 51kQ capacitor and 47nF capacitor,
the internal noise equivalent to the input cannot exceed 0uV
(peak-valley value) within any 10s.
6) Frequency response For sinusoidal signals with frequencies
between 0.67 Hz and 40 H, the response amplitude should be
between 140% and 70% (+3dB-3dB) of the response amplitude
at 5H.
7) Minimum detection signal: for a 10HZ, 50V (peak-valley)
sinusoidal signal, it should be able to produce a clearly visible
deflection.
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6. Product performance indicators
