NJTY T21L

NJTY T21L Digital Multimeter User Manual

Model: T21L

1. Introducció

The NJTY T21L is an advanced auto-range digital multimeter designed for precise electrical measurements. It features a 6000-count display and can measure a wide array of parameters including AC/DC voltage, AC/DC current, resistance, capacitance, frequency, inductance, and temperature. Equipped with Non-Contact Voltage (NCV) detection, automatic shutdown, data retention, and a backlit screen, it is suitable for various applications from circuit board repair to line maintenance and equipment repair.

NJTY T21L High Precision Multimeter with key features
Figure 1: NJTY T21L High Precision Multimeter highlighting key features.

2. Configuració

2.1 Desembalatge i inspecció inicial

Carefully remove the multimeter and all accessories from the packaging. Inspect the device for any signs of damage. Ensure all components listed in the package contents are present.

2.2 Instal·lació de la bateria

The NJTY T21L multimeter requires three (3) 1.5V AAA batteries (not included). To install the batteries:

  1. Localitzeu la tapa del compartiment de la bateria a la part posterior del multímetre.
  2. Utilitzeu un tornavís per obrir el compartiment de la bateria.
  3. Insert three 1.5V AAA batteries, ensuring correct polarity (+ and -).
  4. Substituïu la tapa del compartiment de la bateria i fixeu-la amb el cargol.

2.3 Back Support Bracket

The multimeter features a back support bracket for convenient hands-free operation. Extend the bracket to tilt the multimeter on a flat surface, allowing for easy viewing de mesures.

Multimeter showing back support bracket design for tilted viewing
Figure 2: Multimeter with extended back support bracket.

3. Instruccions de funcionament

3.1 Dispositiu acabatview

Familiarize yourself with the various parts of your multimeter:

Labeled diagram of the multimeter's front panel
Figure 3: Front panel diagram with labeled components.
  • Pantalla: Pantalla digital per a lectures de mesura.
  • Non-contact sensor head/torch: Used for NCV detection and as a flashlight.
  • Non-contact indicator: Lights up during NCV detection.
  • Botó HOLD: Freezes the current reading on the display (Data retention).
  • FUNC/Hz button: Selects functions within a rotary dial setting or switches to frequency measurement.
  • Backlight/Flashlight button: Activates the screen backlight or flashlight.
  • Marcador rotatiu: Selects the measurement function (e.g., DC V, AC V, Resistance, Capacitance, NCV, OFF).
  • Current Jack (MAX 10A FUSED): Input for high current measurements.
  • Common Jack (COM): Common ground connection for all measurements.
  • Function Jack (FUSED 600mA): Entrada per al voltage, resistance, capacitance, frequency, and low current measurements.

3.2 Mesures bàsiques

The T21L features an auto-range function, simplifying operation by automatically selecting the appropriate measurement range.

Multimeter displaying 'Auto range multimeter' feature
Figure 4: Auto-range feature for simplified measurements.

3.2.1 voltage Measurement (DC/AC)

  1. Turn the rotary dial to the 'V' (DC Voltage) or '~V' (AC Voltage) posició.
  2. Connect the red test lead to the 'Function Jack' and the black test lead to the 'Common Jack'.
  3. Place the test probes across the component or circuit to be measured.
  4. Llegeix el voltage valor a la pantalla.

3.2.2 Current Measurement (DC/AC)

  1. Turn the rotary dial to the 'μA', 'mA', or 'A' position (DC or AC current).
  2. For currents up to 600mA, connect the red test lead to the 'Function Jack'. For currents up to 10A, connect the red test lead to the 'Current Jack'. Connect the black test lead to the 'Common Jack'.
  3. Break the circuit and connect the multimeter in series with the component.
  4. Read the current value on the screen.

3.2.3 Mesura de la Resistència

  1. Turn the rotary dial to the 'Ω' (Resistance) position.
  2. Connect the red test lead to the 'Function Jack' and the black test lead to the 'Common Jack'.
  3. Place the test probes across the component to be measured (ensure the circuit is de-energized).
  4. Read the resistance value on the screen.

3.2.4 Mesura de la capacitat

  1. Turn the rotary dial to the 'F' (Capacitance) position.
  2. Connect the red test lead to the 'Function Jack' and the black test lead to the 'Common Jack'.
  3. Place the test probes across the capacitor (ensure the capacitor is discharged before testing).
  4. Read the capacitance value on the screen.

3.2.5 Mesura d'inductància

  1. Turn the rotary dial to the 'H' (Inductance) position.
  2. Connect the red test lead to the 'Function Jack' and the black test lead to the 'Common Jack'.
  3. Place the test probes across the inductor.
  4. Read the inductance value on the screen.
Examples of functional measurements: DC Voltage, AC Voltage, Resistance, and Capacitance
Figura 5: Exemple visualamples of various functional measurements.

3.2.6 Vol. sense contactetage (NCV) Detecció

  1. Turn the rotary dial to the 'NCV' position.
  2. Move the non-contact sensor head close to the AC voltage source (e.g., a live wire).
  3. The multimeter will indicate the presence of AC voltage through an audible beep and/or visual indicator on the screen.
Multímetre que realitza NCV (Volum sense contacte)tage) measurement
Figure 6: Performing NCV non-contact measurement.

3.2.7 Continuity Test (On-off buzzer)

  1. Turn the rotary dial to the 'Ω' position and press the FUNC button until the buzzer symbol appears.
  2. Connect the red test lead to the 'Function Jack' and the black test lead to the 'Common Jack'.
  3. Place the test probes across the circuit or component.
  4. Si hi ha continuïtat (baixa resistència), sonarà el brunzidor.

3.2.8 Diode/Thyristor Test

  1. Turn the rotary dial to the 'Ω' position and press the FUNC button until the diode symbol appears.
  2. Connect the red test lead to the 'Function Jack' and the black test lead to the 'Common Jack'.
  3. Place the test probes across the diode or thyristor.
  4. La pantalla mostrarà el volum d'avançtage drop. Reverse the probes to check for open circuit.
Examples of functional measurements: on-off buzzer, Diode Measurement, and NCV non-contact measurement
Figura 7: Examples of continuity (buzzer), diode, and NCV measurements.

3.3 característiques addicionals

  • Retenció de dades (HOLD): Premeu el botó «HOLD» per congelar la lectura actual a la pantalla. Torneu a prémer-lo per alliberar-lo.
  • Retroiluminació/Llanterna: Press the backlight/flashlight button to turn on the screen backlight or activate the flashlight.
  • Apagat automàtic: The multimeter will automatically power off after approximately 10 minutes of inactivity to conserve battery life.
Multimeter illustrating the automatic shutdown feature
Figure 8: Automatic shutdown feature for power saving.

4. Manteniment

4.1 Neteja

Per netejar el multímetre, netegeu la carcassa amb aiguaamp drap i un detergent suau. No utilitzeu abrasius ni dissolvents. Assegureu-vos que el dispositiu estigui completament sec abans d'utilitzar-lo.

4.2 Substitució de la bateria

When the low battery indicator appears on the screen, replace the three 1.5V AAA batteries as described in Section 2.2.

4.3 Canvi de fusibles

The multimeter is protected by internal fuses. If the current measurement function stops working, the fuse may need replacement. Refer to a qualified technician for fuse replacement to ensure proper type and rating (MAX 10A FUSED and FUSED 600mA).

4.4 Protecció contra caigudes

The multimeter is designed with rubber drop protection to enhance durability and security against accidental drops.

Multimeter with rubber drop protection case
Figure 9: Multimeter featuring rubber drop protection.

5. Solució De Problemes

  • Sense pantalla o pantalla tènue: Check battery levels and replace if necessary. Ensure batteries are installed with correct polarity.
  • Lectures incorrectes: Verify that the correct function is selected on the rotary dial. Ensure test leads are properly connected to the correct jacks and making good contact with the circuit. For resistance/capacitance, ensure the circuit is de-energized.
  • Sense mesura de corrent: Check if the fuse for the current range is blown. Consult a qualified technician for fuse replacement.
  • NCV not detecting: Ensure the NCV sensor is close enough to the AC voltage font.

6. Especificacions

The following table details the specifications for the NJTY T21L Digital Multimeter:

Specifications table for Model T21L
Figure 10: Detailed specifications for NJTY T21L.
FuncióIntervalResolucióPrecisió
DC Voltage60mV/600V/6V/60V/600V0.1 V± 0.5% ± 5
Vol. ACtage60mV/600V/6V/60V/600V0.1 V± 0.4% ± 5
Corrent continu600uA/6000uA/60mA/600mA/6A/10A0.1 mA±1.2%±5 / ±3%±5
Corrent alterna600uA/6000uA/60mA/600mA/6A/10A0.1 mA±1.2%±5 / ±3%±5
Resistent600Ω/6kΩ/60kΩ/6MΩ/60MΩ0.01 MΩ± 0.8% ± 5
Freqüència9Hz/99Hz/999Hz/9KHz/99KHz/999KHz/9MHz0.001 MHz± 1.5% ± 5
Condensadors600pF/60nF/600nF/60uF/600uF/60mF/600mF0.1 mF± 4.0% ± 5
Inductors600uH/6mH/60mH/60mH/6H/60H10 KΩ± 1.0% ± 5
Temp-55~1000°C
Tiristor
On-off buzzer
Retenció de dades
Il·luminació de la pantalla
NCV
Volum baixtage Visualització
Apagat automàtic
Mode de visualització6000 Pantalla
Dimensions generals147 * 71 * 45 mm
Font d'alimentació3x 1.5V AAA battery
Temperatura de funcionament-55~1000°C
CertificacióCE, FCC, RoHS

7. Consells d'usuari

  • Always ensure the circuit is de-energized before measuring resistance or capacitance to prevent damage to the multimeter and ensure safety.
  • When measuring current, always connect the multimeter in series with the load and ensure the correct current jack (mA or 10A) is used to avoid blowing the fuse.
  • Utilize the NCV function for a quick and safe check for live wires before making contact measurements.
  • The auto-range feature is convenient, but for critical measurements, it's good practice to start with a higher range and work your way down if manual range selection were available (though this model is auto-range).
  • Keep the test leads clean and in good condition for accurate readings.

8. Garantia i assistència

Per obtenir informació sobre la garantia, assistència tècnica o consultes sobre el servei, poseu-vos en contacte directament amb el venedor o el fabricant. Conserveu el rebut de compra com a comprovant de compra.

The NJTY T21L Digital Multimeter is certified with CE, FCC, and RoHS standards, indicating compliance with health, safety, and environmental protection standards.


Multímetre digital NJTY T21L: demostració completa de funcions i mésview

Multímetre digital NJTY T21L: demostració completa de funcions i mésview

0:50 • 1280×720 • feature_demo
Multímetre digital NJTY T21L: guia completa de funcions i mesurament

Multímetre digital NJTY T21L: guia completa de funcions i mesurament

2:00 • 720×960 • demostració

Documents relacionats - T21L

Preview Multímetre LCR NJTY T21L: Multímetre digital de rang automàtic amb TRUE RMS - Manual d'usuari
Manual d'usuari complet per al multímetre LCR NJTY T21L, un multímetre digital de rang automàtic amb TRUE RMS. Cobreix les especificacions, la seguretat, el funcionament i les funcions de mesura de vol.tage, corrent, resistència, capacitança, inductància, freqüència i temperatura.
Preview Multímetre LCR NJTY T21L: Multímetre digital de rang automàtic amb TRUE RMS - Manual d'usuari
User manual for the NJTY T21L LCR Meter, an auto-ranging digital multimeter with TRUE RMS. Covers features, safety, technical specifications, and operation for accurate electrical measurements.
Preview NJTY S18D Digital Multimeter User Manual
User manual for the NJTY S18D Digital Multimeter, detailing safety instructions, panel indications, operational guidelines, and technical specifications for accurate electrical measurements. Features include IEC-61010 compliance, backlit LCD, True RMS, and auto-ranging.
Preview Guia de l'usuari del multímetre punter NJTY: característiques, especificacions i instruccions
Guia d'usuari completa per al multímetre punter NJTY, que detalla el seu aspecte, especificacions i funcions de mesura (volts CC/CA).tage, corrent, resistència, capacitança, etc.), i recordatoris importants de seguretat.
Preview Manual d'instruccions del provador de resistència d'aïllament NJTY sèrie T60
Manual d'instruccions detallat per als provadors de resistència d'aïllament analògics NJTY T6005, T6010 i T6015, que cobreix les característiques, el funcionament, la seguretat, les especificacions tècniques i el contingut del paquet.
Preview Multímetre analògic NJTY sèrie 88: manual d'usuari i guia tècnica
Manual d'usuari complet per als multímetres analògics de la sèrie NJTY 88, que cobreix les característiques, les especificacions, les precaucions de seguretat i les instruccions de mesura per a voltatges de CC/CA.tage i corrent, resistència, capacitança, freqüència i més.