GW Instek GDM-452, Operating Manual

1.  Set to the maximum range and reduce it gradually if the measured 

     current is unknown.

2.  If "1" displays on LCD, it indicates over-range, please select a higher 

     range for your measurement.
3.  “        ” indicates the maximum input current. mA input is protected by

   200mA/250V fuse; 10A/250V fuse is used to protect 10A range.

1. Set to the maximum range and reduce it gradually if the measured 

    voltage is unknown.

2. If "1" displays on LCD, it indicates over-range, please select a higher 

    range for your measurement.
3. “        ” indicates not to input voltage higher than 1000V, which may 

 cause damage to the Multimeter or personal injury although the reading

    may be obtained.

4. Extreme care should be taken to avoid electric shock when measuring 

    high voltage.

P/N:82DM-45200M01

Ⅴ．

Making Measurements

Ⅵ．

Maintenance

Ⅶ．

Replacing the Battery

Ⅷ．

Accessories

DC Current

Measuring AC Current

Data Hold

Auto Power Off

Measuring Resistance

Measuring Capacitance

Measuring Frequency

Testing Diodes and Continuity

 Measuring AC Voltage

Measuring DC Current

(1) Power on the Multimeter and inspect 9V battery. Replace the battery 

     if “        ” displays. If not, proceed into next step.

(2) Pay attention to rated voltage or current value next to “        ” near 

     input terminals, any input that go beyond the rating may damage the 

     Multimeter.

LCD display
POWER button

AC+DC button
HOLD button

CANCEL AUTO POWER OFF button

Input jack

1. Insert test leads into input jacks(Red to V and black to COM).

2. Set the function switch to V      range; Connect test leads to the wire 

    under test in parallel, and the positive polarity of the test end will indicate.

Notice

1. Insert black test lead into COM jack and insert red one into V jack;

2. Place function switch at V~ range scope and then connect test leads

    to measurement wires in parallel.

may cause damage to internal wires

1. Insert black test lead into COM jack and insert

not more than 200mA. Insert the red test lead into 

10A jack if measured current is between 200mA and 10A.

2. Place function switch at A       range and then connect testing leads

    to measurement loop in series. It will dispaly current and polarity of 

    red test lead at the same time.

1. Insert black test lead into COM jack and insert red one into mA jack if

    measured current is not more than 200mA. insert red test lead into 

    10A jack if measured current is between 200mA and 10A.

2.  Place function switch at A~ range and connect testing leads to

     measurement loop in series.

1. Please refer to “Notice” for DC current measurement.

1. Insert black test lead into COM jack and insert
2. Place function switch

leads to

1.  Insert the tested capacitor directly into capacitance jacks(without need 

     of test leads).

2.  The floating reading exists every time you switch to another 

     capacitance range and reset to zero before connecting to a tested 

     capacitor, which however will have no impact on the accuracy.

1. Discharge the tested capacitor before measurement, although the 

    capacitance ranges are protected internally, it may also cause damage 

    to the multimeter.

1. Insert red test leads into HZ jack and insert black one into COM jack;

2. Place function switch at kHZ range and connect test leads to frequency

The accuracy cannot be ensured if input signal voltage is higher than 

30Vrms, and please take extreme care.

Insert black test lead 

test leads

Connect test leads

1. Press HOLD button to realize such function;

2. Whether the test leads are disconnected or not will not influence Data 

    Hold function.

1. The Multimeter is designed with automatic power-off circuit to power 

    off after instrument operates for about 15 minutes and enter into 

    sleeping status;

2. Press POWER button twice to wake up the Multimeter from the sleep 

    mode. 

This kind of Multimeter belongs

1000VDC or 750Vrms AC.

“current ranges”

removing test leads

1 pc

Test Leads

This manual contains proprietary information, which is protected by copyright. All 
rights are reserved. No part of this manual may be photocopied, reproduced or 
translated to another language without prior written consent of Good Will company.
The information in this manual was correct at the time of printing. However, Good Will 
continues to improve products and reserves the rights to change specification, 
equipment, and maintenance procedures at any time without notice.

Good Will Instrument Co., Ltd.
No. 7-1, Jhongsing Rd., Tucheng Dist., New Taipei City 236, Taiwan