Extech MM560A, MM570A Operating Manual

User’s Guide

MultiMaster™ Digital MultiMeter Series
With PC Interface

Models:
MM560A
MM570A

A

2

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 / mAμA : Category III and Category IV 600 Volts AC and 300 Volts DC.

MM570A Terminals (to COM) measurement category:

V / A / mAμA : 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

CAUTION

death to the user.
identifies conditions and actions that could cause damage or malfunction

in the instrument.

WARNING

3

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

μA/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

3) PRODUCT DESCRIPTION
Panel Illustration

4

1) 5-4/5 digits 500000
counts LCD display

2) Push-buttons for special

1

functions & features

3) Selector to turn the

2

Power On or Off and
Select a function

A

4) Input Jack for 10A (+)

3

(20A for 30sec) current,
and for T2 (-) function

5) Input Jack (+) for all
functions EXCEPT current

4

μ

A, mA, A) and T2

(
functions

5

6) Common (Ground
reference) Input Jack (-)
for all functions EXCEPT
T2 function

6

7) Input Jack (+) for
milli-amp, micro-amp, and
T2 (+) functions

7

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

5

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.

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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 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, &

In AC Voltage, press
DC Voltage, press
mV Voltage, press

SELECT
SELECT

SELECT

button momentarily to toggle between AC and dBm. In
button momentarily to toggle between DC, and DC+AC. In
button momentarily to select DC, AC, or DC+AC. The new

Hz Line Level Frequency

settings will be saved automatically to the non-volatile memory as power up default. In
DCV and DCmV, press

500000

5-4/5 digits readings. In voltage or current functions, press the

button momentarily to toggle between 4-4/5 digits and

push button

Hz

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-

Ω (

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 1200Ω. The new

impedance value will be saved automatically to the non-volatile memory as power up
default.

dBm

A A A

dBm-Ω

dBm

7

DCV

A A A

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.