EZ DM-311 User manual

WARNING
Before using the meter, you must read the following safety information of
Maximum input specification carefully.
V measurements: Below 1000VDC, 750VAC RMS
measurements: Below 200 (Fuse rating 250V)
10A measurements: Below 10A(Fuse rating 250V)
measurements: Below 600VAC/DC(1 minute)
measurements: Below 600VAC/DC(1 minute)
Hz measurements: Below 250VAC/DC
BAT : Don't input the any voltage, current but battery voltage.
If you don't follow the safety information, DMM SET may be damaged.
And, it can cause a roaring noise or a fire.

DECLARATION OF CONFORMITY
according to ISO/IEC Guide 22 and EN 45014
Manufacturer's Name : EZ Digital Co., Ltd.
Manufacturer's Address : #222-28, Nae-dong, Ojeong-gu,
Bucheon-si, Gyeonggi-do,
KOREA, 421-160
Declares that the product :
Product Name : DIGITAL MULTIMETER
Model Numbers : DM-311, DM-312
Date : Sep. 27. 1995.
Conforms to the following product specification :
Certified by TUV Rheinland
Safety : EN61010-1:1993
(IEC 1010-1:1990+A1:1992, modified)
EMC : EN50081-1:1992
EN50082-1:1992
Supplementary Information :
The product herewith complies with the requirements of the Low Voltage
Directive 73/23/EEC and the EMC Directive 89/336/EEC.
Bucheon, Gyeonggi
Location Cheol Young Kim
Quality Assurance Manager
..

WARRANTY
This instruments is warranted against defects in material and
workmanship for a period of one year from the data of sale.
During the warranty period, EZD will repair or replace it which
Prove to be defective. But warranty shall not apply to defects
resulting from improper or inadequate maintenance by buyer,
In this case, the repair will be billed at a nominal cost.
For warranty service or repair, this instrument must be returned
to a service facility designated by EZD.
Buyer shall prepay shipping charges to EZD and EZD shall pay
Shipping charges to return it to buyer.

INTRODUCTION -- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 1
MULTIMETER SAFETY- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 2
FEATURES - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 4
HOW TO USE THE METER - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 5
Input Terminals - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 5
Function Selector Rotary Switch- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 5
Pushbuttons - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 8
Digital display - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 9
APPLICATIONS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -10
Measuring Voltage (AC/DC) - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -10
Measuring Current (AC/DC) - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -11
(continued on page ii)
CONTENTS
TITLE PAGE

Measuring Resistance - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 12
Tra ns is to r hF E Test - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 1 3
Di od e Test - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 14
Co nt in ui ty Tes t - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -1 5
Battery Test - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -16
Measuring Frequency - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -17
Me as ur in g Ca pa ci ta nc e- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 18
MAINTENANCE - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 19
Ba tt er y Re pl ce me nt - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 20
Fuse Replcement - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 21
SPECIFICATIONS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 22
Specifications (DM-311, 312) - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 22
Spec if ic at io ns ( DM -3 13 ) - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 25
Spec if ic at io ns ( DM -3 41 ) - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 26
CONTENTS, continued
TITLE PAGE

INTRODUCTION
NOTE
All material in this manual applies to the
DM-310SRS AND DM-341 unless otherwise indicated.
This meter has been designed and tested according
to EN 61010-1, Safety Requirements for Electronic
Measuring Apparaturs.
This manual contains information and warnings which
must be followed to ensure safe operation and retain
the meter in safe operation and retain the meter in
safe condition.
HOLSTER (Option)
The meter comes with a snap-on holster that absorbs
shocks and protects the meter from rough handling.
you can also hang the meter on your belt for easy
viewing while probing.
The test leads may be snapped into the holster that
allows you to hold both the meter and probe tip with
one hand.
WARNING
READ"MELTIMETER SAFETY" BEFORE USING THE METER.
Your EZD Digital Multimeter (also referred to as the meter )
is a handheld instrument that is designed for use in the field,
laboratory and at home.
The meter combines the precision of a digital meter with the
speed and versatility of a high resolution.
The meter is powered by a 9V battery and has a rugged
case sealed against dirt, dust and moisture.
A snap-on holster protects the meter from rough handling.
After unpacking the meter, if you notice that the meter is
damaged or something is missing, contact the place of
purchase immediately. Save the shipping container and
packing material in case you have to reship the meter.
The higher input voltage than the maximum one can cause
the roaring noise by the spark gap included for protection.
INTRODUCTION
1

MULTIMETER SAFETY
Before using the meter, read the following safety
information carefully. In the manual the word
"WARNING" is used for conditions and actions that
pose hazards to the user, the word "CAUTION" is
used for conditions and actions that may damage
your meter.
The symbols shown in Figure 1 are used
internationally to denote the electrical functions
and conditions indicated.
Figure 1. international Electrical Symbols
SAFETY DESIGNED
This meter has the feature that warns the dangerous
mismatching between rotary switch's mode selection
position and jack terminal used, Buzzer sound if rotary
switch is not set to Amp mode (10A DC/AC) during
10A terminal which a detector is built in, pluged in by
test lead(only DM-313). To avoid accidentally
applying voltage to 10A terminal, verify that red test
lead is connected to V input terminal before making
voltage measurement. This restriction ensures
protection against burns in the event that voltage is
accidentally applied between 10A and COM terminals.
v/ terminal is colored in red, COM terminal in black
and 10A terminal in Red to be recognized with easy
(refer to Fig.2).
Avoid working alone.
Inspect the test leads for damaged insulation
or exposed.
Select the proper function and range for your
measurement.
MULTIMETER SAFETY
2

1.0001.000 1.0001.000 1.0001.000
Figure 2
* Using Effect (A):No plug in 10A JACK terminal.(Range selector : except 10A position)
(B):Performance good Measurement.
(C): Buzzer sound.
(mismatching) (mismatching)(Good)
MULTIMETER SAFETY
3

Disconnect the live test lead (Red) before
disconnecting the common test lead (Black).
Follow all safety procedures for equipment being
tested. Disconnect the input power and discharge
all high voltage capacitors through a protective
impedance beforetesting in the and functions.
When making a current measurement, turn the
power off before connection the meter in the circuit.
Check the meter fused before measuring current
transformer secondary or motor winding current.
An open fuse may allow high voltage build-up, which
is potentially hazardous.
To take a measurement, use the test lead probes to
make the proper contacts. Remember, insert the meter
in the circuit in parallel for voltage and in series for
current measurements.
WARNING
TO AVOID ELECTRICAL SHOCK OR DAMAGE
TO THE METER, DO NOT APPLY MORE THAN
1000V BETWEEN COMTERMINAL AND EARTH
GROUND.
TO AVOID ELECTRICAL SHOCK, USE CAUTION
WHEN WORKING ABOVE 60V DC OR 30V AC
RMS, SUCH VOLTAGES POSE A SHOCK HAZARD.
FEATURES
3 Digit 2000 count LCD(DM-310SRS)
4 Digit 20000 count LCD(DM-341)
Measurement rate : 2 times/sec
Different colors of input terminals
Low battery indication
Protection for input overload
Dual-slop integration A/D converter system.
Over range indication : Most-significant digit flickered
(DM-313), 1 displayed
Battery life : Typical 200HRS with a regular battery
Temperatures
Operation : 0 ~ 40 (below 80% RH)
Storage : -10 ~ 60 (below 70% RH)
Guaranteed accuracy : 23 5
Accessories : Operating Manual
9V Battery
Test leads(Red&Black 1pair)
Spare fuse(0.25A)
SAFETY
Certified by TUV Rheinland.
- EMC EMI : EN50081-1
EMS : EN50082-1
- Safety : EN61010-1
- Over voltage cat.
- pollution deg.
FEATURES
4

HOW TO USE THE METER
This section describes your meter and how to use it,
For ease of reference, each
description is numbered and keyed the illustration in
page 27, 28 of this manual.
Input terminals
Item ~ describe the input terminals and the different
colors of input terminal allow you to have easy operation.
(See Table 1 for overload limits.)
10A Amperes Input Terminal
For current measurements (AC or DC) up to 10A
continuous when the function
selector switch is in the 10A position.
COM Common Terminal (Black color)
Return terminal for all measurements.
Do not apply more than 1000V between The COM
terminal and Earth ground.
v/ Volts, Ohms, Continuity, BAT, Frequency,
Diode test input Terminal (Red color)
Input Terminal
SOCKET Transistor hFE input terminal
SOCKET capacitance input terminal
Function Selector Rotary Switch
item describes functions that are selected by setting
the rotary switch. The meter is ready for normal operations
and will respond to the rotary switch and pushbuttons.
Volts AC Volts DC
Amperes AC Amperes DC
Resistance Battery Test
Diode Test TR hFE Test
Beeper Sound Continuity Test
Capacitance
Test
Frequency
Test
HOW TO USE THE METER
INPUT TERMINALS
5

Table 1. Input Terminals and Limits(DM-310SRS)
INPUT TERMINALS MIN DISPLAY READING MAX DISPLAY READINGFUNC
TION
RED BLACK DM-311.312 DM-313 DM-311. 312 DM-313
MAXIMUM INPUT
VV/ COM 0.1 0.1 1000V 1000V 1000VDC,750VAC
10A 10A COM 0.01A 0.01A 10.00A 10.00A 10A/250V
V/ COM 10 199.9
COM 1199.9
200 /250V
V/ COM 0.1 0.1 19.99 19.99 600VAC/DC(1min)
Hz V/ COM
10Hz
(DM-312)
-
199.9
(DM-312)
-250VAC/DC
BATV/ COM
1
(DM-311)
-
19.99V
(DM-311)
-
Do not Apply any Voltage
or Current(only Battery)
V/ COM 600VAC/DC(1min)
HOW TO USE THE METER
INPUT TERMINALS AND LIMITS
6

INPUT TERMINALS
FUNCTION
RED BLACK
MIN DISPLAY
READING
MAX DISPLAY
READING
MAXIMUM INPUT
VV/ COM 0.01 1000V 1000VDC,750VAC
10A 10A COM 0.001A 10.000A 10A/250V
COM 1199.99 200 /250V
V/ COM 0.01 19.999 600VAC/DC(1min)
Hz V/ COM 1199.99 250VAC/DC
V/ COM 600VAC/DC(1min)
Table 1. Input Terminals and Limits(DM-341)
HOW TO USE THE METER
INPUT TERMINALS AND LIMITS
7

Pushbuttons(DM-313)
Items ~ describe how to use the pushbuttons.
Press the power button to turn on the meter.
MANUAL RANGING
Press RANGE to select the manual range mode, then
the AUTO annunciator is
disappear (the meter remains in the range it was in
when manual ranging was selected).
In the manual range mode, each time for press range
button, the range increments, and a new value is
displayed. To exit the manual range mode and turn to
the auto ranging, press and hold down range mode
and turn to the auto ranging, press and hold down
range switch for 2 seconds the AUTO annunciator
turns back on.
- MEM
Press MEM button to enter -MEM store mode. The
MEM annunciator is displayed as the last two significant
digits are stored and then subtracted from all the
following inputs. Press the MEM switch again to cancel.
The MEM mode is also canceled whenever the
measurement mode or range is
changed. The MEM operation mode can be very useful
in resistance measurement
errors. It can also be used to measure deviations of
voltage or current measurements.
HOLD(display hold)
Press hold switch to toggle in and out of the touch hold
mode. In the touch hold Mode, the HOLD annunciator is
displayed and the last reading is hold on the display(Except
10A Range).
DC/AC ( /Lo )
Press this switch to measure AC voltage or AC current
in the voltage or current
mode, or to measure low- power ohm in the resistance mode.
Press it again to cancel.
HOW TO USE THE METER
PUSHBUTTONS
8

Digital display
1) DIGITAL DISPLAY
The digital display has a 2000 count (DM-310SRS) or 20000 count (DM-341) display with polarity indication.
2) AUTO AUTO-RANGE (DM-313)
The meter is the auto-range mode and will automatically select range with the best resolution.
The meter powers on in auto-range mode.
3) NEGATIVE POLARITY
Automatically indicates negative inputs.
4) BEEPER
continuity test is enabled.
5) -MEM MODE (DM-313)
When MEM is enabled, indicates as the last two significant digits are stored.
HOW TO USE THE METER
INPUT TERMINALS AND LIMITS
9

CC
KK
AA
LL
BB
CC
KK
AA
LL
BB
DD
RR
EE
DD
RR
EE
1.0001.000
1.0001.000
APPLICATIONS
This section discusses some common applications for your
meter, and alerts you to some considerations to keep in
mind when taking measurements.
Measuring Voltage (AC/DC)
To measure voltage, connect the black lead to common
terminal and red one to v/ terminal, and turn the rotary
switch to DCV or ACV range as Figure 5-1.
Connect the meter in parallel with the load or circuit under
test.
Each of AC/DC voltage ranges presents an input impedance
of approximately 10 in parallel with less than 50 . AC
voltage is AC-Coupled to the 10 input, and frequency
range is 50 to 400
Over range is being indicated by flickered figure 1 in display
(DM-313) and by figure 1 (DM-311, 312, 341)
Figure 5-1. Measuring Voltage
APPLICATIONS
MEASURING VOLTAGE (AC/DC)
10

CC
KK
AA
LL
BB
CC
KK
AA
LL
BB
DD
RR
EE
DD
RR
EE
1.0001.000
1.0001.000
Figure 5-2. Measuring Current
Measuring Current (AC/DC)
If you do not know approximately what the current is, connect
the black lead to common terminal and red one to 10A input
terminal first to see if you have a safe level for the input
(max. 200 ) terminal and turn the rotary switch to DCA or
ACA range as Figure 5-2.
Connect the meter in series with the load or circuit under
test, and note that the frequency range for AC current
measurement is 50 to 400
When measuring current, the meter's internal shunt resistors
develop a voltage across the meter's terminals called "burden
voltage". This voltage drop is very low in your meter, but it may
affect precision circuits or measurements.
Over range is being indicated by flickered figure "1" in display.
(DM-313) and by digit "1" (DM-311, 312, 341)
WARNING
DO NOT APPLY THE VOLTAGE OF MORE THAN
60V DC OR 30V AC RMS.
APPLICATIONS
MEASURING CURRENT (AC/DC)
11

CC
KK
AA
LL
BB
CC
KK
AA
LL
BB
DD
RR
EE
DD
RR
EE
1.0001.000
1.0001.000
Figure 5-3. Measuring Resistance
Measuring Resistance
To measure resistance, connect the black lead to common
terminal and red one to v/ terminal, and turn the rotary
switch to range as Figure 5-3. Connect the test leads
across the resistance under measurement.
CAUTION
Turn off power on the test circuit and discharge all capacitors
before attempting in-circuit resistance measurements, If an
external voltage is present across a component, it will be
impossible to take an accurate measurement of the
resistance of that component.
To measure in-circuit resistance shunted by a semiconductor
junction, Press the /Lo function and make sure the Lo
annunciator is displayed of the LCD(DM-313)
Due to the sensitive nature of the 200 range, a residual
resistance is present. This resistance will display itself, if the
probes are shorted. This residual resistance is due to the
lead, track and switch resistance. To obtain measurement
within the stated accuracy when using the 200 range
subtract from your value the residual resistance reading.
APPLICATIONS
MEASURING RESISTANCE
12

CC
KK
AA
LL
BB
DD
RR
EE
1.0001.000
Transistor hFE Test (DM-312, 341)
Set rotary function switch to hFE range as Figure 5-4. insert
the leads (Emitter, Base, Collector) into the proper holes of
the socket on the front panel, according to transistor type
NPN or PNP.
The display reads approximate eFE value at the test condition
of Base current 2.4 and VCE 3V.
Figure 5-4.hFE Test
NOT USED
APPLICATIONS
TRANSISTOR hFE TEST
13