Triplett MM300 User manual

User Manual
MM300
True RMS Manual Ranging Digital Multimeter
Introduction
Congratulations on your purchase of the Triplett MM300 True RMS Manual 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, 3999 counts
Safety
•Circuits under test must be de-energized 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 insulation.
•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
APO auto power off
Battery capacity
▲
Relative test
Data hold
Meter Description
1) Protective Holster
2) LCD Display
3) “Select.” Button
When you measure the current, 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.
4) “ ” Button
After pressing the button, 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.
Press the button for 2 seconds to turn the Backlight ON.
Press again for 2 seconds to turn OFF.
5) Function/Range Rotary Switch
This switch can be used to select desired function and
range.
6) “A” Jack
Plug-in connector for the red test lead for Current
(200mA ~ 10A) measurements.
7) “COM” Jack
Plug-in connector for black (negative) test lead.
8) “INPUT” Jack
Plug-in connector for the red test lead for all measurements except current (≥200mA) measurements

Operation
DC & AC VOLTAGE MEASUREMENT
1. Connect red test lead to “INPUT” jack, Black lead to “COM” jack.
2. Set RANGE switch to desired VOLTAGE range, if the voltage to be measured
is not known beforehand, set switch to the highest range and reduce it until
satisfactory reading is obtained.
3. Connect test leads to device or circuit being measured.
4. Turn on power of the device or circuit being measured voltage value will
appear on Digital Display along with the voltage polarity.
DC/AC CURRENT MEASUREMENT
1. Red lead to “INPUT”. Black lead to “COM” (for measurements between 200mA
and 10A connect red lead to “10A” jack with fully depressed.)
2. Range switch to desired range.The default function of the meter is the
measurement of DCA.
3. Press “select” button to switch to ACA measurement mode.
4. Open the circuit to be measured, and connect test leads in series with the load
in with current is to measure.
5. Read current value on Digital Display.
6. Additionally, “A” function is designed for intermittent use only. Maximum
contact time of the test leads with the circuit is 15 seconds, with a minimum
intermission time of seconds between tests.
RESISTANCE MEASUREMENT
1. Red lead to “INPUT”. Black lead to “COM”.
2. Range switch to desired Ωrange.
3. If the resistance being measured is connected to a circuit, turn off power and
discharge all capacitors before measurement.

4. Connect test leads to circuit being measured.
5. Read resistance value on Digital Display.
DIODE MEASUREMENT
1. Red lead to “INPUT”, Black lead to “COM”.
2. RANGE switch to “ ” range.
3. Connect the red test lead to the anode of the diode to be measured and black
test lead to cathode.
4. The forward voltage drop in mV will be displayed. If the diode is reversed,
figure “OL” will be shown.
TEMPERATURE MEASUREMENT
1. Range switch to ºC or ºF range, it will display room temperature in ºC or ºF
value.
2. Connect the K-type thermoelectric couple to “INPUT” and “COM” jacks.
3. The display will read Temperature value ºC or ºF.
4. Press “select” button, can switch the unit of measurement of temperature. The
default is temperature measurement in Celsius.
NOTE: The K-type thermocouple Max. Operating temperature of Probe:
250˚C/482˚F (300˚C/572˚F short-term). The sensor supplied with the instrument
is an ultra- fast response naked bead thermocouple suitable for many general
purpose applications.
AUDIBLE CONTINUITY TEST
1. Red lead to “INPUT”, Black lead to “COM”.
2. RANGE switch to “ ” range.
3. Connect test leads to two points of circuit to be tested. If the resistance is lower
than 30Ω±20Ω, the buzzer will sound.
BATTERY TEST
1. Connect the black test lead to the "COM" jack and the red test lead to the
"INPUT" jack (Note: The polarity of the red test lead is positive "+").
2. According to the different type of the battery (1.5V, 9V,) to be tested, set the
range switch to the desired BATT range.
3. Connect the test leads to the battery to be tested.
4. Read the reading on the display. The polarity of the red test lead connection
will be indicated.

“ ” FUNCTION
5. After pressingthe button, thepresent 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.
6. Pressing the button more than 2 seconds will turn the Backlight ON and
OFF.
Auto Power Off
If you don’t operate the meter for about 15 minutes, it will 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
Accuracies are guaranteed for 1 year, 23ºC±5ºC, less than 80%RH
DC VOLTAGE
RANGE
RESOLUTION
ACCURACY
2V
1mV
±（0.8%of rdg+5D）
20V
10mV
200V
100mV
600V
1V
±（1.0% of rdg+5D）
OVERLOAD PROTECTION: 220V rms AC for 200mV range and 600V DC or
600V rms for all ranges.
AC VOLTAGE
RANGE
RESOLUTION
ACCURACY
200V
100mV
±（1.0% of rdg+5D）
600V
1V

RESPONSE: Average responding, calibrated in rms of a sine wave.
FREQUENCY RANGE: 45Hz ~ 450Hz
OVERLOAD PROTECTION: 600V DC or 600V rms for all ranges.
AUDIBLE CONTINUITY
OVERLOAD PROTECTION: 15 second maxi- mum 220 V rms.
DC CURRENT
RANGE
RESOLUTION
ACCURACY
200mA
100µA
±（1.5% of rdg+4D）
10A
10mA
±（2.0% of
rdg+10D）
OVERLOAD PROTECTION: 500mA/600V fuse or 10A/600V fuse
MEASURING VOLTAGE DROP: 200mV
AC CURRENT
Range
Resolution
Accuracy
200mA
100µA
±(1.5% of rdg + 4D)
10A
10mA
±(2.0% of rdg + 4D)
Overload Protection:
µA and mA ranges: F0.5A/600V fuse
10A ranges: F10A/600V fuse
Max. Input Current:
“INPUT” jack: 200mA
“A” jack: 10A
(For measurements>5A: duration <10 seconds, interval >15 minutes)
Voltage Drop: 200mA 10A ranges: 200mV
Frequency Range: 40Hz ~ 400Hz
Response: Average, calibrated in rms of sine wave
RANGE DESCRIPTION
Built-in buzzer sounds if resistance is
less then 30±20Ω

RESISTANCE
RANGE
RESOLUTION
ACCURACY
200Ω
0.1Ω
±（1.0% of rdg+10D）
2KΩ
1Ω
20KΩ
10Ω
200KΩ
100Ω
2MΩ
1KΩ
OVERLOAD PROTECTION: 15 seconds maxi- mum 220Vrms.
TEMPERATURE (with K-TYPE PROBE)
RANGE
RESOLUTION
ACCURACY
-40℃~150℃
1℃
±
（1.0%+4D）
150℃~1370℃
±
（1.5%+15D
）
-40℃~302℃
1℃
±
（1.0%+4D）
302℃~1999℃
±
（1.5%+15D
）
BATTERY TEST
BATTERY AND FUSE REPLACEMENT
Fuse rarely need replacement and blow almost always as a result of operator
error.
If “ ” appears in display, it indicates that the battery should be replaced.
To replace battery & Fuse (500mA/600V or 10A/600V) remove the 1 screws in
the bottom of the battery case, simply remove the old, and replace with a new
one. Be careful to observe polarity .Remove the hostel and remove the bottom
cover of the meter to replace the fuse. Please replace the appropriate fuse
according to operation manual.
Range
Resol.
Internal Resistance
9V
10mV
910Ω
1.5V
1mV
150Ω

ACCESSORIES
Operator’s instruction manual
Set of test leads
Gift box
K-type thermoelectric couple
1.5V 3, AAA s
General specifications
Display : LCD, 1999 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) : 145×70×35mm
Weight : Approx 157g
Approvals
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 way 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