Wavetek Meterman DM2 Operator's Manual

¤

TM

Digital Multimeter/Multi Tester

Operator’s Manual

Model DM2

Digital Multimeter

• Manual de Instrucciones

– 1 –

WARRANTY

The DM2 Multimeter is warranted against any defects of material or
workmanship within a period of one (1) year following the date of pur­chase of the multimeter by the original purchaser or original user.
Any multimeter claimed to be defective during the warranty period
should be returned with proof of purchase to an authorized Wavetek
Meterman Service Center or to the local Wavetek Meterman dealer or
distributor where your multimeter was purchased. See maintenance
section for details. Any implied warranties arising out of the sale of a
Wavetek Meterman multimeter, including but not limited to implied
warranties of merchantability and fitness for a particular purpose, are
limited in duration to the above stated on (1) year period. Wavetek
Meterman shall not be liable for loss of use of the multimeter or other
incidental or consequential damages, expenses, or economical loss
or for any claim or claims for such damage, expenses or economical
loss.

Some states do not allow limitations on how long implied warranties
last or the exclusion or limitation of incidental or consequential dam­ages, so the above limitations or exclusions may not apply to you.

This warranty gives you specific legal rights, and you may also have
other rights which vary from state to state.

CONTENTS

Warning and Precautions 2
Unpacking and Inspection 3
Operation 3
Specifications 7
Maintenance 8
Repair 9

SYMBOLS

Direct current
Alternating current
Ground connection
Attention! Refer to Operating Instructions

Dangerous voltage may be present at terminals

WARNING AND PRECAUTIONS

The DM2 is not recommended for high voltage industrial use appli­cations, but for use with low energy circuits to 500VAC or 1000VDC,
or high energy circuits only to 250 VAC or VDC. ■Do not exceed the
maximum overload limits per function (see specifications) nor the
limits marked on the instrument itself. ■ Exercise extreme caution
when: measuring voltage >20 V / / current >10mA / / AC power line
with inductive loads / / AC power line during electrical storms / / cur­rent, when the fuse blows in a circuit with open circuit voltage > 600
V / / servicing CRT equipment. ■ Inspect DMM, test leads and
accessories before every use. Do not use any damaged part. ■ Never
ground yourself when taking measurements. Do not touch exposed
circuit elements or probe tips. ■ Always measure current in series
with the load – NEVER ACROSS a voltage source. Check fuse first.

■ Never replace a fuse with one of a different rating. ■ Do not oper­ate instrument in an explosive atmosphere.

– 2 –

– 3 –

ACCESSORIES

VC12 Vinyl Carring Case
RTL25 Replacement Test Leads

UNPACKING AND INSPECTION

Upon removing your new digital multimeter (DM2) from its packag­ing, you should have the following items:

1. DM2 Digital Multimeter

2. Test Lead Set (1 black, 1 red)

3. 9 Volt Battery (in meter)

4. Warranty Card

5. Operator’s Manual

6. One Spare Fuse (0.8A/250V)

If any of the above items are missing or are received in a damaged
condition, please contact the distributor from whom you purchased
the unit.

Familiarization (Fig.1)

1. Function/Range Switch: Selects the Function and Range desired.

2. COM Input Terminal: Ground input connector. 500V (DC + AC
Peak) Maximum voltage between COM and earth ground.

3. V Ω Input Terminal: Positive input connector for voltage, resistance,
and diode test. Maximum input rating is 1000VDC, 500VAC.

4. 200mA Input Terminal: Positive input connector for up to 200mA
current. Fused.

5. Lo Bat: Indicates batter is low.

OPERATING INSTRUCTIONS

Range Selection

If magnitude to be measured is unknown, always start with the high­est range.

PRECAUTION!

Overload Condition: Range overload is indicated by a "1." Or by a "-

1." In the display with all other digits blanked. This is normal in the
ohms range when the leads are not connected to anything. In all other
situations, the user must take immediate steps to remove the cause of

– 4 –

the overload condition from the meter. Select the next higher range
until a value is displayed. If overload condition still exists in the
highest range, remove test leads from the measurement setup as it is
beyond the range of the meter.

5

4

3

2

1

Model DM2

Fig.1

V

200
m

20

2

2000

k

200

200k

1000

20k

OFF

2k

FUSED 200mA

1000V

500V
MAX

500

200

DM2

20

V

COM

V

200
u

2m

20m

200
m

A

– 5 –

VOLTAGE MEASUREMENT

1.Turn off power to the device under test and discharge all capacitors.

2.Set the Function/Range switch to the desired voltage type (AC or DC)

range.

3.Plug the black test lead into the COM jack on the DMM and connect

the test lead point to a grounded point (the reference point for mea­surement of voltage).

4.Plug the red test lead into the V jack on the DMM and connect the test

lead point to the circuit where a voltage measurement is required.
Voltage is always measured in parallel across a test point.

5.Turn on power to the circuit/device to be measured and make the volt-

age measurement. Reduce the range setting if set too high until a sat­isfactory reading is obtained.

6.After completing the measurement, turn off power to the circuit /

device under test, discharge all capacitors and disconnect the DMM
test leads.

CURRENT MEASUREMENT

1.Turn off power to the device under test and discharge all capacitors.

2.Set the Function/Range switch to the desired current range.

3.Plug the black test lead into the COM jack on the DMM and connect

the test return branch for the current to be measured.

4.Plug the red test lead into the 200mA current jack of the DM2.

Current measurements are always made with the meter in series with
the test branch. The circuit must be broken and the meter put in series
by placing the red test lead point to the test node for current.

5.Turn on power to the circuit/device under test and make the current

measurement. Reduce the range setting if set too high until a satisfac­tory reading is obtained.

6.After completing the measurement, turn off power to the circuit/device

under test, discharge all capacitors, disconnect the DMM test leads
and re-connect the circuit branch.

Note: The current jack has a protective fuse installed to protect the

meter from damage and the user from harm if a current larger
than specified is applied at the input. If the quick acting fuse
blows, replace with a like fuse.

– 6 –

RESISTANCE MEASUREMENTS

1.Turn off any power to the resistance to be measured. Discharge any

capacitors. Any voltage present during a resistance measurement will
cause inaccurate readings and could damage the meter if exceeding
the overload protection of 500VDC or AC.

2.Set the Function/Range switch to the desired resistance range.

3.Plug the black test lead into the COM jack on the DMM and connect

the test lead point to one end of the resistor,

4.Plug the red test lead into the Ω jack on the DMM and connect the

test lead point to the other end of the resistor.

5.Adjust the Function/Range switch to the resistance range that gives the

most accurate measurement reading.

Note: Test lead resistance can interfere when making low resistance

measurements and should be subtracted from resistance readings
for accuracy. Select 200Ω range and make a firm contact
between the two test lead points (short them together). The dis­play value is the test lead resistance to be subtracted from resis­tance reading. Open circuits will be displayed as an overload
condition.

DIODE TEST

Diode Test checks the forward bias of diode function.

1.Turn off power to the device under test and discharge all capacitors.

2.Set the Function/Range switch to

3.Plug the black test into the COM jack on the DMM and connect the

test lead point to the cathode of the diode.

4.Plug the red test lead into the V Ω jack on the DMM and connect the

test lead point to the anode of the diode. The meter’s display indicates
the forward voltage drop (approximately 0.7V for silicone diode or

0.4V for germanium diode). Meter will display overload condition for
an open diode

5. Reverse the test lead connections to the diode to perform a reverse

bias test of the diode junction. A "1" (over-range) indicates a good
diode because a good diode junction has practically infinite resistance.

Notes: Overload conditions for both reverse and for ward bias tests indi-

cate an open diode. A low voltage reading for both bias tests indicates
a shorted diode. If the diode is shunted by a resistor of 1000 ohms or
less, it must be removed from the circuit before taking the measure­ment.