Triplett - MM350 User Manual - 2019

User Manual



M
M350


True RMS Auto Ranging
Digital
Multimeter


















Introduction



Congratulations on your purchase of the Triplett MM350 True RMS Auto
Ranging Digital
Multimeter.

This instrument performs AC/DC voltage, AC/DC Current, Resistance, Audible
Continuity, Diode, Temperature measurements and
Frequency

measurements,
it is a
3

3
/
4

digits,
3
999 counts Auto R
anging DMM.





Safety



•

Circuits under test must be de
-
ener
gized and isolated before
connections are made (except for voltage measurements).


•

Circuit connections must not be touched during a test. Use extreme
caution when working near bare conductors and bus bars. Accidental
contact with conductors could result in

electrical shock.


•

Use caution when working near voltages above 60VDC or 30VACrms.


•

After insulation tests, capacitors must be discharged.


•

Test leads (including alligator clips) must be in good working order,
clean and without broken or cracked insulatio
n.


•

When servicing, use only specified replacement parts.


International Safety Symbols



Caution, refer to this manual before using this meter


Dangerous Voltages



Meter is protected throughout by double or reinforced insulation




ELECTRICAL
SYMBOLS



DC (Direct Current)
.



AC (Alternating Current)
.


DC or AC


Important safety information.

Refer to the manual
.


Dangerous voltage maybe present
.


Earth ground
.


Low battery


Fuse
.



Diode


Continuity test

°C

Centigrade

°F

Fahrenheit


AUTO


Auto range


Conforms to European Union directive
.


Double insulated
.

APO

A
PO
auto power off


B
attery capacity

▲


R
elative test


Data

hold


Meter Description



1)

3
3
/
4

digit LCD, with a max. reading
of
3
999


2)

Range Button

The
meter defaults to the auto range
mode when you measure the
voltage, current, resistance

or
capacitance
. When the meter is in
the auto range mode, “AUTO” is
displayed.

To enter and exit the manual range
mode:

a. Press “ RANGE” button

The meter enters the ma
nual range
mode and the symbol “AUTO” turns
off.

b. To exit the manual range mode,
press and hold down the “RANGE”
button for 2 seconds, the meter returns to the auto range mode and the symbol
“AUTO” is displayed.


3)

“
Select
.” Button

When you measure the cur
rent, pressing this button will switch the meter
between DC function and AC function.


When you measure the diode or the continuity, pressing this button will switch
the meter between the diode and the continuity functions.



“
” Button

After pressing the b
utton, the present reading is held on the display, meanwhile
“
” is displayed on the LCD as an indicator. To exit the Hold Mode, press
the button again and the indicator “
” will disappear.

pressing the button

more then 2 second
，
Backlight turned on
，
pressin
g the
button

more then 2 second again
，
Backlight turned
off


4)

“
Max/Min
”

Button
:

After pressing the button Displays the maximum and minimum
values during the test. The maximum and minimum values are cleared after the
changes the test functio
n,or meter be off
.




5)

Relative

Button

This Meter will display relative measurements in all functions
,

except frequency.


6)


Hz%

bu
tton


When you measure the
Hz%
, pressing this button will switch the meter between
HZ

function and duty cycle

function.

When you measure the

ACV
,
pressing this button will switch the meter will show
the frequency of the AC voltage
.


7)

Function/Range Switch

This switch can be used to select desired function and range.


8)


“A” Jack

Plug
-
in connector for the red test lead for Current (200mA ~ 10A)
measurem
ents
.


9)


“COM” Jack

Plug
-
in connector for black(negative) test lead.


10)

“INPUT” Jack

Plug
-
in connector for the red test lead for all measurements

except
current(≥200mA) measurements.






Operation





Measuring Voltage

1)

Connect the
black

test lead to the “COM” jack and the
red

to the “INPUT” jack.

2)

Set the function switch to V

or V

range.

Select auto range or manual range with the “RANGE” button.

3)

In manual range, if the voltage magnitude to be measured is unknown
beforehand, select the h
ighest range.

4)

Connect the test leads across the source or load to be measured.

5)

Read LCD display. The polarity of the
red

lead connection will be indicated when
making a DC measurement.

Note:

a.

In small range, the meter may display an unstable reading when th
e test
leads have not been connected to the load to be measured. It is normal and
will not affect the measurements.

b.

In manual range mode, when the meter shows the over range symbol “OL”,
a higher range must to be selected.

c.

To avoid damage to the meter, don
’t measure a voltage which exceeds
6
00Vdc (for DC voltage measurement) or
60
0Vac (for AC voltage
measurement).


Measuring Current

1)

Connect the
black

test lead to the “COM” jack. If the current to be measured is
less than 200mA, connect the red test lead to
the “INPUT” jack. If the current is
between 200mA and 10A, connect the red test lead to the “10A” jack instead.

2)

Set
the range switch to desired μA
, mA

or A

range.

If the current magnitude to be measured is not known beforehand, set the ranges
switch to
the highest range position and then reduce it range by range until
satisfactory resolution is obtained.

3)

Select DC current measurement or AC current measurement with the “
Select
”
Button.

4)

Select auto range or manual range with the “R
ange
” button. In manual r
ange, if
the current magnitude to be measured is not known beforehand, select the
highest range.

5)

Connect test leads in series with the circuit to be measured.

6)

Read the reading on the display. For DC current measurement, the polarity of the
red test lead co
nnection will be indicated as well.


Note:

When the display shows the over range symbol “OL”, a higher range must be
selected.


Measure Resistance

1)

Connect the
black

test lead to the “COM” jack and the
red

to the “INPUT” jack
(Note: The polarity of the red t
est lead is positive “+”).

2)

Set the range switch to “
”
position

3)

Set the “
Select
”
button

to“

”range

4)

Select auto range or manual range with the “R
ange
” button. In manual range, if
the current magnitude to be measured is not known beforehand, select the
highest range.

5)

Connect the test leads across the load to be measured.

6)

Read the reading on the display.






Note:

a.

For resistance measurements >1M
Ω, the meter may take a few seconds to
stabilize reading. This is normal for high
-
resistance measurement.

b.

When
the input is not connected, i.e. at open circuit, the symbol “OL” will
be displayed as an over range indicator.

c.

Before measuring in
-
circuit resistance, be sure that the circuit under test
has all power removed and all capacitors are fully discharged.


Continuity Test

1)

Connect the
black

test lead to the “COM” jack and the
red

to the “INPUT” jack
(Note: The polarity of the red test lead is positive “+”).

2)

Set the range switch to “
”

position

3)

Press the “
Select
” Button to select continuity measurement mode,
and the symbol
“
” will appear as an indicator.

4)

Connect the test leads across the load to be measured.

5)

If the circuit resistance is lower than about
3
0
Ω, the built
-
in buzzer will sound.



Diode Test

1)

Connect the
black

test lead to the “COM” jack and the
red

to the “INPUT” jack
(Note: The polarity of the red test lead is positive “+”).

2)

Set the range switch to “
”

position.

3)

Press the “
Select
” Button to select continuity measurement mode, and the symbol

“
” will appear as an indicator.

4)

Connect the red test lea
d to the anode of the diode to be tested and the black test
lead to the cathode.

5)

The meter will show the approximate forward voltage of the diode. If the
connections are reversed, “OL” will be shown on the display.



Capacitance

Measuring

1)

Connect the
black

test lead to the COM jack and the
red

to the “INPUT” jack.

2)

Set the range switch to “
”
position

3)

Press the “
Select
” Button to select continuity measurement mode, and the symbol
“
mF
” will appear as an indicator.

4)

Connect test leads across the capacitor under
measure and be sure the polarity of
connection is observed.

Note:
When the capacitance under measure is above 100uF, it needs at least
10

second
s

to make readings stable.



Measuring Temperature

1)

Set the range switch to

“
°C
”
or
“
°F

”range.

2)

Insert the black (or “
-
“) plug of the K type thermocouple to the “COM” jack, and
the red( or “+”) plug to the “INPUT” jack.

3)

Carefully touch the end of the thermocouple to the object to be measured.

4)

Wait a while, read the reading on the display.



Frequency

/ Duty cycle measure

1)

Connect the
black

test lead to the COM jack and the
red

to the

“INPUT” jack.

2)

Set the range switch to “
Hz %
” range.

3)

Press

the “
Select
” Button to select

“Hz”
or
“
duty cycle
”

mode

4)

C
onnect test leads across the source or load under
measurement.

NOTE:

The input voltage should be between 200mV and 10V rms AC. If the voltage
is more than 10V rms, reading may be out of the accuracy range.



Auto Power Off

If you don’t operate the meter for about 15 minutes, it will turn off automatically
. To
turn on it again, just rotate the range switch or press a button.

In the
power off

state, press and “
Select
” button

to
Rotary
range

switch, you can
cancel the
auto power off

function
,

“APO” symbol disappear from the

LCD
.







Specifications




Accuracy is guarant
e
ed for 1 year 23°C
±
5°C less than 80%RH

5
-
1. DC VOLTAGE (Auto ranging)

Range

Resolution

Accuracy

4
00mV

0.1mV

±
(0.8% of rdg + 5dgts)

4
V

1mV

±
(0.
8
% of rdg +
3
dgts)

4
0V

10mV

4
00V

100mV

6
00V

1V

±
(1.0% of rdg + 5dgts)


Input
Impedance: 10MΩ

Overload Protection:

6
00V DC

or 600
AC rms





(200mV range: 250V DC/AC rms)

Max. Input voltage:
6
00V DC

5
-
2. AC VOLTAGE (Auto ranging)

Range

Resolution

Accuracy

400m
V

1mV

±
(1.2% of rdg +
5
dgts)

4
V

1mV

±
(1
.0
% of rdg +
8
dgts)

4
0V

10mV

4
00V

100mV

60
0V

1V

±
(1.2% of rdg + 8dgts)

Input Impedance: 10M
Ω

Frequency Range: 40Hz ~ 400Hz

Overload Protection:
6
00V DC

or 600
AC rms

Response: Average, calibrated in rms of sine wave

Max. Input voltage:
60
0V AC rms


5
-
3. TEMPERATURE

Rang
e

Resolution

Accuracy

-
40 ~

1370°
C

1°C

-
40
°C~150°C:
±
(2
.5
% +
4
)

150
°C~1370°C:
±
(2
.5
% +
4
)

-
40 ~

1°F

-
40
°F~302°F:
±
(
2.5
% +
4
)


2000°
F

3
02
°F~2000°F:
±
(2
.5
% +
4
)

NOTE:

Different temperature sensors are configured in different temperature test
ranges, and normal
temperature sensors are provided for standard configuration

5
-
4. DC CURRENT

Range

Resolution

Accuracy

4
00μA

0.1μA

±
(
1.2
% of rdg +
8
dgts)

4
000μA

1μA

4
0mA

10μA

4
00mA

100μA

4
A

1mA

10
A

10mA

Overload Protection:


μA

and mA

ranges: F0.5A/
60
0V fuse


4
A and
1
0A ranges: F
10
A/
60
0V fuse

Max. Input Current:


“INPUT” jack: 200mA


“A” jack: 10A


(For measurements>5A: duration <10 seconds, interval >15 minutes)

Voltage Drop:

4
00μA,
4
0mA and
4
A ranges:
4
0mV




4
000μA,
4
00mA and 10A ranges:
4
00mV




5
-
5. AC
CURRENT

Range

Resolution

Accuracy

4
00μA

0.1μA

±
(1.
5
% of rdg +
8
dgts)

4
000μA

1μA

4
0mA

10μA

4
00mA

100μA

4
A

1mA

±
(
2.0
% of rdg +
10
dgts)

10A

10mA

Overload Protection:


μA

and mA

ranges: F0.5A/
60
0V fuse


4
A and 10A ranges: F
10
A/
60
0V fuse

Max. Input

Current:


“INPUT” jack: 200mA


“A” jack: 10A


(For measurements>5A: duration <10 seconds, interval >15 minutes)

Voltage Drop:

4
00μA,
4
0mA and
4
A ranges:
4
0mV




4
000μA,
4
00mA and 10A ranges:
4
00mV


Frequency Range: 40Hz ~ 400Hz

Response: Average, calibrat
ed in rms of sine wave


5
-
6
. RESISTANCE (Auto Ranging)

Range

Resolution

Accuracy

4
00
Ω

0.1
Ω

±
(1.
5
% of rdg +
3
dgts)

4
K
Ω

1
Ω

4
0K
Ω

10
Ω

4
00K
Ω

100
Ω

4
M
Ω

1K
Ω

4
0M
Ω

10K
Ω

Open Circuit Voltage: about 0.25V

Overload Protection: 250V DC/AC rms

5
-
7
. Diode and
Continuity

Range

Introduction

Remark


The approximate forward
voltage drop will be
displayed

Open circuit
voltage: about
1.5V


The built
-
in buzzer will
sound if the resistance is
less than about
3
0
Ω.

Open circuit
voltage: about
0.5V

Overload Protection: 250V DC/AC rms

For continuity test: When the resistance is between
5
0
Ω and 100Ω, the buzzer may
sound or may not sound. When the resistance is more than 100Ω, the buzzer won’t
sound.


5
-
8
. Capacitance

Range

Resolution

Accuracy

4
0nF

10pF

±
(8% of rdg + 10dgts)

4
00nF

100pF

±
(5% of rdg + 5dgts)

4
uF

1nF

4
0uF

10nF

1
00uF
-
2mF

100nF


5
-
10
.
FREQUENC
Y

Range

Accuracy

5/50/500/5K

50K/500K/5MHz

±
(
1.0
%
of rdg
+ 3
dgts
)





General specifications

Display



: LCD,
3
999 counts updates
2/sec

LCD Size



: 55 x 31mm

Polarity Indication


: “
-
” displayed automatically

Over
-
range Indication

: “OL” displayed

Low Battery Indication

: “
” displayed

Range select


: auto or manual

Operation Temperature

: 0°C to 40°C, less than
80
%RH

Storage
Temperature

:

-
10°C to 50°C, less than 85%RH

Battery Type


: 1.5V x
3
, AAA size

Dimension

(H×W×D)


:
5.7 x 2.8 x 1.4" (145 x 70 x 35mm)

Weight



:
5.5oz. (157g)




Approvals



8
. BATTERY REPLACEMENT

If the sign “
” appear on the display, it indicates
battery should be replaced.
Remove screws and open the back case, replace the exhausted battery with new
batteries (Size AAA, 1.5V x
3

or equivalent).


9
. ACCESSORIES

User Manual,

Test leads, Type K Thermocouple with Banana Connectors


10
. FUSE REPLACEMENT

Fuse rarely needs replacement and is blown almost always as a result of operator’s
error. This meter uses a fuse: F
1:
500mA/
60
0V

and F2: 10A/600V

fast action. To
replace the fuses, open the
meter back

cover, replace the damaged fuse with a new
fuse of the s
pecified ratings.

Reinstall the battery cover and lock this cover.


Warranty Information

Triplett / Jewell Instruments extends the following warranty to the original purchaser of
these goods for use. Triplett warrants to the original purchaser for use that

the products sold
by it will be free from defects in workmanship and material for a period of (1) one year from
the date of purchase. This warranty does not apply to any of our products which have been
repaired or altered by unauthorized persons in any wa
y or purchased from unauthorized
distributors so as, in our sole judgment, to injure their stability or reliability, or which have
been subject to misuse, abuse, misapplication, negligence, accident or which have had the
serial numbers altered, defaced, or

removed. Accessories, including batteries are not
covered by this warranty

Copyright
©

2019 Triplett