Matco Tools MD251 User manual

USER'S MANUAL
MD251 Basic Multimeter

1
1) SAFETY
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.
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 II
1000V, CAT III 600V and CAT IV 300V AC & DC.
Terminals (to COM) measurement category:
V : Category II 1000V, CAT III 600V and CAT IV 300V AC & DC.
mAA : Category III 500Vac and 300Vdc.
A : Category III 600Vac and 300Vdc.
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.

2
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. Only use the test lead provided with the equipment or UL
Listed Probe Assembly with rating or better.
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
3) PRODUCT DESCRIPTION
Note: Top of the line model is used as representative for illustration purposes. Please refer to your
respective model for function availability.
1) 3-5/6 digits 6000 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 milli-amp and
micro-amp current functions
5) Input Jack for all functions
EXCEPT current (A, mA, A)
functions
6) Common (Ground reference)
Input Jack for all functions
7) Input Jack for 8A (15A for 30sec)
current function
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.
JACK
JACK
!

4
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.
True RMS
True RMS is a term which identifies a DMM that responds accurately to the effective RMS value
regardless of the waveforms such as: square, sawtooth, triangle, pulse trains, spikes, as well as
distorted waveforms with the presence of harmonics. 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
Crest Factor
Crest Factor is the ratio of the Crest (instantaneous peak) value to the True RMS value, and is
commonly used to define the dynamic range of a True RMS DMM. A pure sinusoidal waveform has
a Crest Factor of 1.4. A badly distorted sinusoidal waveform normally has a much higher Crest
Factor.
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 means a good ability to reject the effect of AC noise
in 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 cause digit rolling or offset in voltage measurements. This series has a CMRR
specifications of >60dB at DC to 60Hz in ACV function; and >100dB at DC, 50 and 60Hz in DCV
function. If neither NMRR nor CMRR specification is specified, a DMM's performance will be
uncertain.
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.

5
DCV, ACV, & Line Frequency functions
Press the Hz push-button for one second or more to activate or to exit Hz.
!
DCV
JACK
JACK
ACV
!
JACK
JACK
!
JACK
JACK
Hz
Note:
*Input sensitivity varies automatically with function range selected before activating the Hz function.
6V function range has the highest and the 1000V range has the lowest. 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 set the most appropriate trigger level. You can also press the
RANGE button momentarily to select another trigger level manually. If the Hz reading becomes
unstable, select lower sensitivity to avoid electrical noise. If the reading shows zero, select higher
sensitivity.
*Number of Bar-graph pointer is used to indicate input range (sensitivity) selected. 1/2/3/4 pointers
indicate 6/60/600/1000V, 6/10/-/-A, 60/600/-/-mA or 600/6000/-/-uA is selected in corresponding V,
A, mA or uA function respectively. ( “-” means range not available)
*The Hz of mV function is designed specially for logic level (3V or 5V family) frequency
measurement.

6
Resistance, Continuity, Diode test functions
Press the SELECT button momentarily to select the subject functions in sequence. Last selection
will be saved as power up default for repeat measurement convenience.
CAUTION
Discharge capacitors before making any measurement. Large value capacitors should be
discharged through an appropriate resistance load.
CAUTION
Using resistance and continuity function in a live circuit will produce false results and may damage
the instrument. In many cases the suspected component must be disconnected from the circuit to
obtain an accurate reading
Continuity function is convenient for checking wiring connections and operation of switches. A
continuous beep tone indicates a complete wire.
Normal forward voltage drop (forward biased) for a good silicon diode is between 0.400V to
0.900V. A reading higher than that indicates a leaky diode (defective). A zero reading indicates a
shorted diode (defective). An OL indicates an open diode (defective). Reverse the test leads
connections (reverse biased) across the diode. The digital display shows OL if the diode is good.
Any other readings indicate the diode is resistive or shorted (defective).

7
DCmV, ACmV
Press the SELECT button momentarily to select the subject functions in sequence. Last selection
will be saved as power up default for repeat measurement convenience.
A, mA, and A Current functions
Press SELECT button momentarily to toggle between DC and AC.Last selection will be saved as
power up default for repeat measurement convenience.

8
*Note: When measuring a 3-phase system, special attention should be taken to the phase-to-
phase voltage which is significantly higher than the phase-to-earth voltage. To avoid exceeding the
voltage rating of the protection fuse(s) accidentally, always consider the phase-to-phase voltage as
the working voltage for the protection fuse(s).
Electric Field EF-Detection
At Volt or Current function, press the EF button for one second or more and release to toggle to
EF-Detection feature. The meter displays “E.F.” when it is ready. Signal strength is indicated as a
series of bar-graph segments on the display plus variable beep tones.
• Non-Contact EF-Detection: An antenna is located along the top-right end of the meter, which
detects electric field surrounds current-carrying conductors. It is ideal for tracing live wiring
connections, locating wiring breakage and to distinguish between live or earth connections.
• Probe-Contact EF-Detection: For more precise indication of live wires, such as distinguishing
between live and ground connections, use the Red (+) test probe for direct contact measurements.
Hold
The hold feature freezes the display for later view. Press the HOLD button momentarily to toggle
the hold feature.
Relative Zero ( ) mode
Relative zero allows the user to offset the meter consecutive measurements with the displaying
reading as the reference value. Practically all displaying readings can be set as relative reference
value including MAX/MIN feature readings. Press the REL button momentarily to toggle relative
zero mode.
Manual or Auto-ranging
Press the RANGE button momentarily to select manual-ranging, and the meter will remain in the
range it was in, the LCD turns off. Press the button momentarily again to step through the
ranges. Press and hold the button for 1 second or more to resume auto-ranging.
Note: Manual ranging feature is not available in Hz and functions.

9
Set Beeper Off
Press the RANGE button while turning the meter on to temporarily disable the Beeper feature.
Turn the rotary switch OFF and then back on to resume.
Beep-Jack™ Input Warning
The meter beeps as well as displays “InEr” to warn the user against possible damage to the meter
due to improper connections to the A, mA, or A input jacks when other function (like voltage
function) is selected.
Auto-Power-Off (APO)
The Auto-Power-Off (APO) mode turns the meter off automatically to extend battery life after
approximately 34 minutes of no rotary switch or push button operations. To wake up the meter
from APO, press the SELECT, CREST or REC button momentarily or turn the rotary switch OFF
and then back on. Always turn the rotary switch to the OFF position when the meter is not in use
Disabling Auto-Power-Off
Press the SELECT button while turning the meter on to temporarily disable the Auto-Power-Off
(APO) feature. Turn the rotary switch OFF and then back on to resume.
5) MAINTENANCE
WARNING
To avoid electrical shock, disconnect the meter from any circuit, remove the test leads from the
input jacks and turn OFF the meter before opening the case. Do not operate with open case. Install
only the same type of fuse or equivalent
Cleaning and Storage
Periodically wipe the case with a damp cloth and mild detergent; do not use abrasives or solvents.
If the meter is not to be used for periods of longer than 60 days, remove the battery and store it
separately
Trouble Shooting
If the instrument fails to operate, check battery, fuses, leads, etc., and replace as necessary.
Double check operating procedure as described in this user’s manual
If the instrument voltage-resistance input terminal has subjected to high voltage transient (caused
by lightning or switching surge to the system) by accident or abnormal conditions of operation, the
series fusible resistors will be blown off (become high impedance) like fuses to protect the user and
the instrument. Most measuring functions through this terminal will then be open circuit. The series
fusible resistors and the spark gaps should then be replaced by qualified technician.

10
Battery and Fuse replacement
Battery use: 1.5V AAA Size battery x 2
Fuses use:
Fuse (FS1) for AmA current input:
0.63A/500Vac, IR 50kA, F fuse
Fuse (FS2) for A current input:
10A/600Vac, IR 100kA, F fuse
Battery and Fuse replacement:
Loosen the screw from the access
cover of the case bottom. Lift the
access cover. Replace the batteries or
fuse. Re-fasten the screw.

11
GENERAL SPECIFICATION
Display: 3-5/6 digits 6,000 counts
Update Rate: 5 per second nominal
24 Segments Bar graph: 40 per second max
Operating Temperature: 0oC to 40oC
Relative Humidity: Maximum relative humidity 80% for temperature up to 31oC decreasing
linearly to 50% relative humidity at 40oC
Altitude: Operating below 2000m
Storage Temperature: -20oC ~ 60oC, < 80% R.H. (with battery removed)
Temperature Coefficient: Nominal 0.15 x (specified accuracy)/ oC @ (0oC ~ 18oC or 28oC ~
40oC), or otherwise specified
Sensing: Average sensing
Pollution Degree: 2
Safety: Double insulation per IEC61010-1 2nd Ed., EN61010-1 2nd Ed., UL61010-1 2nd Ed. &
CAN/CSA C22.2 No. 61010.1-0.92 to Category II 1000V, CAT III 600V and CAT IV 300V AC & DC
Transient Protection: 6.5kV (1.2/50s surge)
Terminals (to COM) Measurement Category:
V : Category II 1000V, CAT III 600V and CAT IV 300V AC & DC.
mAA : Category III 500Vac and 300Vdc.
A : Category III 600Vac and 300Vdc.
E.M.C. : Meets EN61326-1:2006 (EN55022, EN61000-3-2, EN61000-3-3, EN61000-4-2,
EN61000-4-3, EN61000-4-4, , EN61000-4-5, EN61000-4-6, EN61000-4-8, EN61000-4-11)
In an RF field of 3V/m:
Capacitance function is not specified
Other function ranges:
Total Accuracy = Specified Accuracy + 100 digits
Performance above 3V/m is not specified
Overload Protection:
uA & mA: 0.63A/500Vac, IR @500Vac
A: 10A/600Vac IR 100kA @600Vac
V: 1050 Vrms, 1450 Vpeak
AutoCheckTM, mV, Ohm & others: 600 Vrms
Low Battery: Below approx. 2.3V
Power Supply: 1.5V AAA Size battery X 2
Power Consumption (typical): 3.5mA
APO Consumption (typical): 10A
APO Timing: Idle for 34 minutes
Dimension: 161*80*50mm L*W*H (With Holster)
Weight: Approx. 340 gm (With Holster)
Auto-ranging Relative Zero mode; Display Hold; EF-Detection (NCV)
Input warning detection

12
Accessories: Test lead pair; batteries installed; user’s manual; BKP60 banana plug type-K
Electrical Specification
Accuracy is given as +/- (% of reading digits + number of digits) or otherwise specified @ 23oC +/-
5oC and less than 75% R.H.
AC Voltage
RANGE
Accuracy
50Hz ~ 400Hz
60.00mV, 600.0mV
1.0% + 5d
6.000V, 60.00V, 600.0V,
1000V
CMRR: >60dB @ DC to 60Hz, Rs=1k
Input Impedance: 10M, 50 pF nominal
Ohm
RANGE
Accuracy
600.0, 6.000K, 60.00K,
600.0K
0.5%+4d
6.000M
0.7%+4d
60.00M
1.2%+4d
Open Circuit Voltage: 0.45VDC typical
DC Voltage
RANGE
Accuracy
60.00mV
0.4%+5d
600.0mV
0.2%+3d
6.000V, 60.00V, 600.0V,
1000V
NMRR: > 60dB @ 50Hz/60Hz
CMRR: > 100dB @ DC, 50Hz/60Hz; Rs=1k
Input Impedance: 10M, 50 pF nominal

13
Audible Continuity Tester
Audible Threshold: Between 10and 80
Response time: 32ms
Diode Tester
RANGE
Accuracy
1.000V
1.0% + 3d
Test Current: 0.56mA typically
Open Circuit Voltage: < 1.8VDC typically
DC Current
RANGE
Accuracy
Burden
Voltage
600.0A
0.5%+5d
0.10 mV/uA
6000A
0.5%+3d
60.00mA
0.5%+5d
1.7 mV/mA
600.0mA
0.5%+3d
6.000A
1.2%+6d
0.03V/A
8.00A1)
1.8%+6d
1) 8A continuous, >8A to 15A for 30 sec. max
with 5 minutes cool down interval
AC Current
RANGE
Accuracy
Burden
Voltage
50HZ ~400HZ
600.0A, 6000A
1.0%+3d
0.10 mV/uA
60.00mA, 600.0mA
1.7 mV/mA
6.000A
1.2%+6d
0.03V/A
8.00A1)
1.8%+6d
1) 8A continuous, >8A to 15A for 30 sec. max
with 5 minutes cool down interval
Logic Level Hz (mV Function)
RANGE
Sensitivity
(square wave)
5.00 Hz ~ 500.0 kHz
3 Vpeak
5.00 Hz ~ 1.000 MHz
5 Vpeak
Accuracy: 0.03%+2d
Hz (Line) @ ACV, DCV, Current &
Function
Sensitivity
(Sine RMS)
Range
6V
0.4V
10Hz - 10kHz
60V
4V
10Hz - 50kHz
600V
40V
10Hz - 50kHz
1000V
400V
45Hz - 1kHz
600A
40A
10Hz - 10kHz
6000A
400A
10Hz - 10kHz
60mA
4mA
10Hz - 10kHz
600mA
40mA
10Hz - 10kHz
6A
1A
10Hz - 1kHz
10A
6A
10Hz - 1kHz
Accuracy: 0.03%+3d
Non-Contact EF-Detection
Typical Voltage
Bar-Graph
Indication
20V (tolerance: 10V ~ 36V)
-
55V (tolerance: 23V ~ 83V)
- -
110V (tolerance: 59V ~ 165V)
- - -
220V (tolerance:124V ~ 330V)
- - - -
440V (tolerance:250V & 1000V)
- - - - -
Indication: Bar-graph segments & audible beep
tones proportional to the field strength
Detection Frequency: 50/60Hz
Detection Antenna: Top-right end of the meter
Probe-Contact EF-Detection: For more precise
indication of live wires, such as distinguishing
between live and ground connections, use
the Red (+) test probe for direct contact
measurements

14

LIMITED WARRANTY
Matco Tools warrants to the original product purchaser that each product it manufactures will be
free from defects in material and workmanship under normal use and service within a period of
Three years from the date of purchase. Matco Tools warranty does not apply to accessories, fuses,
fusible resistors, spark gaps, batteries or any product which, in Matco Tools’opinion, has been
misused, altered, neglected, or damaged by accident or abnormal conditions of operation or
handling.
THIS WARRANTY IS EXCLUSIVE AND IS IN LIEU OF ALL OTHER WARRANTIES,
EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY IMPLIED WARRANTY OR
MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE OR USE. MATCO TOOLS
WILL NOT BE LIABLE FOR ANY SPECIAL, INDIRECT, INCIDENTAL OR CONSEQUENTIAL
DAMAGES.
www.matcotools.com
PRINTED ON RECYCLABLE PAPER, PLEASE RECYCLE
COPYRIGHT © MMXIV BTC, ALL RIGHTS RESERVED
P/N: 7M1C-1011-0010 PRINTED IN TAIWAN

MANUAL DEL
USUARIO
Multímetro básico MD251

1
1) SEGURIDAD
Términos de este manual
ADVERTENCIA identifica condiciones y acciones que podrían causar lesiones o hasta la
muerte del usuario como resultado.
PRECAUCIÓN identifica condiciones y acciones que podrían causar daños o un mal
funcionamiento del instrumento.
Este manual contiene información y advertencias que deben seguirse para la operación segura del
instrumento y para mantener el instrumento en condiciones de operación seguras. Si el
instrumento se utiliza de manera diferente a la especificada por el fabricante, la protección provista
por el instrumento puede ser afectada. Este medidor está diseñado sólo para uso en interiores.
La clasificación de protección del multímetro, para el usuario, es de doble aislamiento según las
normas IEC61010-1 2da Ed., EN61010-1 2da Ed., UL61010-1 2da Ed. y CAN/CSA C22.2
No. 61010.1-0.92 hasta la Categoría II 1000 V, CAT III 600 V y CAT IV 300 V CA y CD.
Categorías de medidas de los terminales (al COM):
V : Categoría II 1000 V, CAT III 600 V y CAT IV 300 V CA y CD.
mAA : Categoría III 500 VCA y 300 VCD.
A : Categoría III 600 VCA y 300 VCD.
Según IEC61010-1 2da Ed. (2001) en las categorías de medición
Categoría de medición IV (CAT IV) es para las mediciones realizadas en la fuente de la
instalación de bajo voltaje. Los ejemplos son: medidores de electricidad y mediciones en
dispositivos primarios de exceso de corriente y unidades de control de voltaje de cresta.
Categoría de medición III (CAT III) es para mediciones realizadas en la instalación del edificio.
Los ejemplos son: mediciones en tarjetas de distribución, circuitos magnéticos, cableado en que
se incluyen cables, barras de conducción, cajas de conexiones, interruptores, salidas de enchufe
en la instalación fija y equipos para uso industrial y algunos otros equipos, como por ejemplo,
motores estacionarios con conexión permanente a la instalación fija.
Categoría de medición II (CAT II) es para las mediciones realizadas en circuitos que están
conectados directamente con la instalación de bajo voltaje. Ejemplos son: mediciones en
electrodomésticos, herramientas portátiles y equipos similares.

2
ADVERTENCIA
Para reducir el riesgo de incendio o electrocución, no exponga este producto a la lluvia o
humedad. Para evitar peligro de electrocución, observe las precauciones de seguridad adecuadas
cuando esté trabajando con voltajes de más de 60 VCD o 30 VCA rms. Estos niveles de voltaje
presentan peligro de electrocución al usuario. No toque con las manos las puntas de las sondas
de prueba o el circuito que está probando mientras se le aplica energía al circuito que se está
midiendo. Mantenga sus dedos detrás de los protectores para dedos en las sondas de prueba
durante la medición. Inspeccione las sondas de prueba, conectores y sondas de medición en
cuanto a cualquier aislamiento dañado o metal expuesto antes de utilizar el instrumento. Si se
encuentra cualquier defecto, reemplácelos inmediatamente. No mida ninguna corriente que
exceda la clasificación de corriente del fusible de protección. No intente realizar una medición de
corriente en un circuito en donde el voltaje de circuito abierto está por encima de la clasificación
de voltaje del fusible de protección. Cualquier voltaje sospechoso de circuito abierto debe ser
verificado con las funciones de voltaje. Nunca intente realizar una medición de voltaje con la
sonda de prueba insertada en el enchufe de entrada A/mA o A. Reemplace el fusible quemado
solamente con otro de la clasificación adecuada según lo especifica este manual. Solo use la
sonda de prueba provista con el equipo o un conjunto de sonda de prueba listado por UL con su
clasificación actual o mejor.
PRECAUCIÓN
Desconecte las sondas de prueba de los puntos de prueba antes de realizar cambios en las
funciones. Siempre programe el instrumento para el mayor rango y vaya disminuyendo en caso de
que el valor sea desconocido cuando está en el modo de rango manual.
SÍMBOLOS ELÉCTRICOS INTERNACIONALES
!
¡Precaución! Refiérase a la explicación en este manual
¡Precaución! Riesgo de electrocución
Tierra
Aislamiento doble o reforzado
Fusible
CA--Corriente alterna
CD--Corriente directa
2) DIRECTRICES CENELEC
Estos instrumentos se conforman con la directriz CENELEC de bajo voltaje 2006/95/EC y con la
directriz de compatibilidad electromagnética 2004/108/EC.

3
3) DESCRIPCIÓN DEL PRODUCTO
Nota: Se utiliza el modelo más avanzado como representativo para fines de ilustración. Por favor
refiérase a su modelo respectivo para la disponibilidad de las funciones.
1) Pantalla LCD de 6000 conteos y
3-5/6 dígitos
2) Botones de pulsación para
funciones y características
especiales
3) Selector rotativo para encender y
apagar (ON/OFF) y seleccionar las
funciones
4) Enchufe de entrada para las
funciones de corriente de
miliamperios y microamperios
5) Enchufe de entrada para todas
las funciones EXCEPTO las
funciones de corriente (A, mA, A)
6) Enchufe de entrada Común
(referencia a Tierra) para todas las
funciones
7) Enchufe de entrada para las
funciones de corriente de 8 A (15 A
durante 30 seg.)
Gráfico de barras analógico
El gráfico de barras analógico ofrece una indicación visual de las mediciones similar a una aguja
de medidor tradicional analógico. Es excelente para la detección de contactos defectuosos,
identificar clics de potenciómetro e indicar picos de la señal durante los ajustes.
JACK
JACK
!