1-机床移动 26-07-06 17-11-19.txt CH2 W=1.0ms

A = FFT amplitude converted to dB for visualization; it is not instantaneous voltage.
图中虚线为 125kHz、200kHz、250kHz 判断边界，用于评估 500kSPS 原型卡的覆盖风险。

Decision Summary / 决策摘要

分类 / ClassCH2-北京物声 / B_transition_or_mixed
<=125 kHz58.73%
<=200 kHz79.96%
>250 kHz4.89%
400 kHz-1 MHz0.98%
说明 / Note多通道代表图；比例来自完整文件 1ms FFT 汇总。

Metadata

{
  "file": "1-机床移动 26-07-06 17-11-19.txt",
  "channel_index": 2,
  "label": "CH 2-北京物声",
  "sample_rate_hz": 2000000.0,
  "window_ms": 1.0,
  "hop_ms": 1.0,
  "start_s": 0.0,
  "duration_s": 1.2,
  "frames": 1200,
  "freq_bins": 1001,
  "amplitude_unit": "FFT amplitude derived from mV waveform, not instantaneous voltage",
  "report_note": "multi-channel representative t-f-A"
}