GW Instek GDM-356 - Manual (Page 15)

15
The AC voltage measurement has 4 measurement
positions on the rotary switch: 2V, 20V, 200V and 750V
To measure AC Voltage, connect the Meter as follows:
Measurement Operation(3)
1. Insert the red test lead into the V
Ω
terminal and
the black test lead into the COM terminal.
2. Set the rotary switch to an appropriate measurement
position in V range.
3. Connect the test leads across with the object being
measured. The measured value shows on the display,
which is effective value of sine wave (mean value
response).
Note
l If the value of voltage to be measured is unknown,
use the maximum measurement position (750V) and
reduce the range step by step until a satisfactory
reading is obtained.
l The LCD displays "
1 "indicating the existing selected
range is overloaded, it is required to select a higher
range in order to obtain a correct reading.
l In each range, the Meter has an input impedance of
approx. 10M
Ω
This loading effect can cause
measurement errors in high impedance circuits. If
the circuit impedance is less than or equal to 10k
Ω
,
the error is negligible (0.1% or less).
l When AC voltage measurement has been completed,
disconnect the connection between the testing leads
and the circuit under test.
GDM-356