Extech Instruments MultiMaster MM560A User manual

User’s Guide
MultiMaster™ Digital MultiMeter Series
With PC Interface
Models:
MM560A
MM570A
A

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1) SAFETY
This manual contains information and warnings that must be followed for operating the instrument
safely and maintaining the instrument in a safe operating condition. If the instrument is used in a
manner not specified by the manufacturer, the protection provided by the instrument may be impaired.
The meter is intended only for indoor use.
The meter protection rating, against the users, is double insulation per IEC61010-1 2nd Ed.,
EN61010-1 2nd Ed., UL61010-1 2nd Ed. and CAN/CSA C22.2 No. 61010.1-0.92 to Category III 1000
Volts AC & DC and Category IV 600 Volts AC & DC.
MM560A Terminals (to COM) measurement category:
V : Category III 1000 Volts AC & DC, and Category IV 600 Volts AC & DC.
A / mAA : Category III and Category IV 600 Volts AC and 300 Volts DC.
MM570A Terminals (to COM) measurement category:
V / A / mAA : Category III 1000 Volts AC & DC, and Category IV 600 Volts AC & DC.
Per IEC61010-1 2nd Ed. (2001) Measurement Category
Measurement Category IV (CAT IV) is for measurements performed at the source of the low-voltage
installation. Examples are electricity meters and measurements on primary overcurrent protection
devices and ripple control units.
Measurement Category III (CAT III) is for measurements performed in the building installation.
Examples are measurements on distribution boards, circuit- breakers, wiring, including cables,
bus-bars, junction boxes, switches, socket-outlets in the fixed installation, and equipment for industrial
use and some other equipment, for example, stationary motors with permanent connection to the fixed
installation.
Measurement Category II (CAT II) is for measurements performed on circuits directly connected to
the low voltage installation. Examples are measurements on household appliances, portable tools and
similar equipment.
TERMS IN THIS MANUAL
WARNING identifies conditions and actions that could result in serious injury or even death
to the user.
CAUTION identifies conditions and actions that could cause damage or malfunction in the
instrument.

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WARNING
To reduce the risk of fire or electric shock, do not expose this product to rain or moisture. To avoid
electrical shock hazard, observe the proper safety precautions when working with voltages above 60
VDC or 30 VAC rms. These voltage levels pose a potential shock hazard to the user. Do not touch test
lead tips or the circuit being tested while power is applied to the circuit being measured. Keep your
fingers behind the finger guards of the test leads during measurement. Inspect test leads, connectors,
and probes for damaged insulation or exposed metal before using the instrument. If any defects are
found, replace them immediately. Do not measure any current that exceeds the current rating of the
protection fuse. Do not attempt a current measurement to any circuit where the open circuit voltage is
above the protection fuse voltage rating. Suspected open circuit voltage should be checked with
voltage functions. Never attempt a voltage measurement with the test lead inserted into the A/mA or
A input jack. Only replace the blown fuse with the proper rating as specified in this manual.
CAUTION
Disconnect the test leads from the test points before changing functions. Always set the instrument to
the highest range and work downward for an unknown value when using manual ranging mode.
INTERNATIONAL ELECTRICAL SYMBOLS
!Caution ! Refer to the explanation in this Manual
Caution ! Risk of electric shock
Earth (Ground)
Double Insulation or Reinforced insulation
Fuse
AC--Alternating Current
DC--Direct Current
2) CENELEC Directives
The instruments conform to CENELEC Low-voltage directive 2006/95/EC and Electromagnetic
compatibility directive 2004/108/EC

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3) PRODUCT DESCRIPTION
Panel Illustration
A
1
2
3
4
5
6
7
1) 5-4/5 digits 500000
counts LCD display
2) Push-buttons for special
functions & features
3) Selector to turn the Power
On or Off and Select a
function
4) Input Jack for 10A (+)
(20A for 30sec) current, and
for T2 (-) function
5) Input Jack (+) for all
functions EXCEPT current
(  A, mA, A) and T2
functions
6) Common (Ground
reference) Input Jack (-) for
all functions EXCEPT T2
function
7) Input Jack (+) for
milli-amp, micro-amp, and
T2 (+) functions

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Average sensing RMS calibrated
RMS (Root-Mean-Square) is the term used to describe the effective or equivalent DC value of an AC
signal. Most digital multimeters use average sensing RMS calibrated technique to measure RMS
values of AC signals. This technique is to obtain the average value by rectifying and filtering the AC
signal. The average value is then scaled upward (calibrated) to read the RMS value of a sine wave. In
measuring pure sinusoidal waveform, this technique is fast, accurate, and cost effective. In measuring
non-sinusoidal waveforms, however, significant errors can be introduced because of different scaling
factors relating average to RMS values.
AC True RMS
AC True RMS, normally refers as True RMS, identifies a DMM function that is AC coupled, and
responds accurately only to the effective RMS AC component value regardless of the waveforms.
However, DC component plays an important role in the distorted non-symmetrical waveforms, and will
also be of interest sometimes. A full wave rectified sine waveform is a good example, and the AC true
RMS function will only give the AC component reading which is at 43.6% of the total effective DC+AC
RMS reading.
DC+AC True RMS
DC+AC True RMS calculates both of the AC and DC components given by the expression
when making measurement, and can responds accurately to the
total effective RMS value regardless of the waveform. Distorted waveforms with the presence of DC
components and harmonics may cause:
1) Overheated transformers, generators and motors to burn out faster than normal
2) Circuit breakers to trip prematurely
3) Fuses to blow
4) Neutrals to overheat due to the triplen harmonics present on the neutral
5) Bus bars and electrical panels to vibrate
AC Bandwidth
AC bandwidth of a DMM is the range of frequencies over which AC measurements can be made within
the specified accuracy. It is not the frequency measurement function, and is the frequency response of
the AC functions. A DMM cannot accurately measure the AC value with frequency spectrums beyond
the AC bandwidth of the DMM. Therefore, wide AC bandwidth plays an important role in high
performance DMMs. In reality, complex waveforms, noise and distorted waveforms contain much
higher frequency spectrum than its fundamental.
NMRR (Normal Mode Rejection Ratio)
NMRR is the DMM's ability to reject unwanted AC noise effect that can cause inaccurate DC
measurements. NMRR is typically specified in terms of dB (decibel). This series has a NMRR
specification of > 60dB at 50 and 60Hz, which is a good and definite ability to reject the effect of AC
noise when making DC measurements.
CMRR (Common Mode Rejection Ratio)
Common mode voltage is voltage present on both the COM and VOLTAGE input terminals of a DMM,
with respect to ground. CMRR is the DMM's ability to reject common mode voltage effect that can

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cause digit rolling or offset in voltage measurements. This series has a CMRR specifications of > 80dB
at DC to 60Hz in ACV function; and > 120dB at DC, 50 and 60Hz in DCV function. If neither NMRR nor
CMRR specification is specified, a DMM's performance will be uncertain.
Analog bar-graph
The analog bar graph provides a visual indication of measurement like a traditional analog meter
needle. It is excellent in detecting faulty contacts, identifying potentiometer clicks, and indicating signal
spikes during adjustments. Analog bar-graph is not available in AC+DC True RMS Voltage & Current
modes.
4) OPERATION
CAUTION
Before and after hazardous voltage measurements, test the voltage function on a known source such
as line voltage to determine proper meter functioning.
AC Voltage, DC Voltage, DC+AC Voltage, & Hz Line Level Frequency
In AC Voltage, press SELECT button momentarily to toggle between AC and dBm. In DC Voltage,
press SELECT button momentarily to toggle between DC, and DC+AC. In mV Voltage, press SELECT
button momentarily to select DC, AC, or DC+AC. The new settings will be saved automatically to the
non-volatile memory as power up default. In DCV and DCmV, press 500000 button momentarily to
toggle between 4-4/5 digits and 5-4/5 digits readings. In voltage or current functions, press the
Hz push button momentarily to activate or to exit Line Level Frequency measuring function. Line
Level Frequency measuring function is designed especially for noisy electrical high voltage signals.
Note: In dBm function, power up default reference impedance will be displayed for 1 second before
displaying the dBm readings. Press dBm-(RANGE) button momentary to select different reference
impedance of 4, 8, 16, 32, 50, 75, 93, 110, 125, 135, 150, 200, 250, 300, 500, 600, 800, 900, 1000, up
to 1200. The new impedance value will be saved automatically to the non-volatile memory as power
up default.
A A A
dBm dBm-Ω dBm

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A A A
DCV ACV Hz
Note: Line Level Frequency measuring function input sensitivity varies automatically with voltage (or
current) function range selected. The lower the measuring range the higher the sensitivity. That is, mV
function has the highest and the 1000V range has the lowest as in voltage function ranges. It is
recommended to first measure the signal voltage (or current) level then activate the Hz function in that
voltage (or current) range to automatically get the most appropriate trigger level. When activated from
voltage function, you can also press the RANGE button momentarily to select another trigger level
range manually. The analog bargraph pointer will point at the selected trigger level range scale 1, 2, 3,
or 4. If the Hz reading is unstable, select lower sensitivity to avoid electrical noise. If the reading shows
zero, select higher sensitivity.

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Hz Logic Level Frequency and % Duty Cycle functions
Press SELECT button momentarily to toggle between Hz and % (duty cycle) readings. The new
setting will be saved automatically to the non-volatile memory as power up default. Press 500000
button momentarily to toggle between 5 full digits and 6 full digits Hz readings.
A A A
Note: Unlike the Line Level Frequency measuring function as previously stated, this Logic Level
Frequency function is set only at the highest input sensitivity for measuring digital type electronic
signals.

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T1-T2 Dual Channels Temperature function (MM570A only)
Press SELECT button momentarily to toggle between C and F readings, and the new setting will be
saved automatically in the non-volatile memory as power up default. Press T1-T2 (RANGE) button
momentarily to select T1, T2, or T1-T2 readings.
Note: Insert the banana plug K-type temperature bead probe with correct polarities. Dual
channels T1-T2 readings require 2 probes.
A A A
CF
T
2
T-T
2
1

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Resistance, Continuity functions
Press SELECT button momentarily to toggle between and Continuity functions. The new
setting will be saved automatically to the non-volatile memory as power up default. Continuity function
is convenient for checking wiring connections and operation of switches. A continuous beep tone
indicates a complete wire.
A A
CAUTION
Using resistance or continuity function in a live circuit will produce false results and may damage the
meter. In many cases the suspected component must be disconnected from the circuit to obtain an
accurate reading.