Pintek PA-677, Instruction Manual

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5. Adjust the probe channel and oscilloscope’s time base as necessary to
get a clear and stable view of the signal. Set the oscilloscope input to DC
volts to see both the AC and DC currents; set the channel to AC to see
the AC current only.
The current drawn by different devices look much different than that of
others. While the RMS current can only be used in low frequency current,
the momentary peaks may be quite high. Figure 3 shows the difference
between the line current drawn by a resistive load and a motor controller.
Figure 3: Typical current waveforms
Congratulations on your purchase of the PA-677, a multifunctional current
probe. When connecting to a digital meter, use the recommended
MT-246N (BNC-to-banana adapter). Connect the black lead to the meter
COM (black letters on the meter), and the red lead to the V
Ω input (red
letters on the meter).
To measure only AC current, set the meter to measure AC volts.
To measure DC current, set the meter to measure DC volts. Note the
current convention arrow on the probe to get the proper polarity reading.
To increase the measurement sensitivity of the PA-677 current probe, loop
additional turns of the wire under test through the jaws. See Figure 4. The
sensitivity of the PA-677 current probe is multiplied times the number of
loops in the jaws. For example: 500 mV/A X 4 turns = 2000 mV/A.