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.

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:
- Localitzeu la tapa del compartiment de la bateria a la part posterior del multímetre.
- Utilitzeu un tornavís per obrir el compartiment de la bateria.
- Insert three 1.5V AAA batteries, ensuring correct polarity (+ and -).
- 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.

3. Instruccions de funcionament
3.1 Dispositiu acabatview
Familiarize yourself with the various parts of your multimeter:

- 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.

3.2.1 voltage Measurement (DC/AC)
- Turn the rotary dial to the 'V' (DC Voltage) or '~V' (AC Voltage) posició.
- Connect the red test lead to the 'Function Jack' and the black test lead to the 'Common Jack'.
- Place the test probes across the component or circuit to be measured.
- Llegeix el voltage valor a la pantalla.
3.2.2 Current Measurement (DC/AC)
- Turn the rotary dial to the 'μA', 'mA', or 'A' position (DC or AC current).
- 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'.
- Break the circuit and connect the multimeter in series with the component.
- Read the current value on the screen.
3.2.3 Mesura de la Resistència
- Turn the rotary dial to the 'Ω' (Resistance) position.
- Connect the red test lead to the 'Function Jack' and the black test lead to the 'Common Jack'.
- Place the test probes across the component to be measured (ensure the circuit is de-energized).
- Read the resistance value on the screen.
3.2.4 Mesura de la capacitat
- Turn the rotary dial to the 'F' (Capacitance) position.
- Connect the red test lead to the 'Function Jack' and the black test lead to the 'Common Jack'.
- Place the test probes across the capacitor (ensure the capacitor is discharged before testing).
- Read the capacitance value on the screen.
3.2.5 Mesura d'inductància
- Turn the rotary dial to the 'H' (Inductance) position.
- Connect the red test lead to the 'Function Jack' and the black test lead to the 'Common Jack'.
- Place the test probes across the inductor.
- Read the inductance value on the screen.

3.2.6 Vol. sense contactetage (NCV) Detecció
- Turn the rotary dial to the 'NCV' position.
- Move the non-contact sensor head close to the AC voltage source (e.g., a live wire).
- The multimeter will indicate the presence of AC voltage through an audible beep and/or visual indicator on the screen.

3.2.7 Continuity Test (On-off buzzer)
- Turn the rotary dial to the 'Ω' position and press the FUNC button until the buzzer symbol appears.
- Connect the red test lead to the 'Function Jack' and the black test lead to the 'Common Jack'.
- Place the test probes across the circuit or component.
- Si hi ha continuïtat (baixa resistència), sonarà el brunzidor.
3.2.8 Diode/Thyristor Test
- Turn the rotary dial to the 'Ω' position and press the FUNC button until the diode symbol appears.
- Connect the red test lead to the 'Function Jack' and the black test lead to the 'Common Jack'.
- Place the test probes across the diode or thyristor.
- La pantalla mostrarà el volum d'avançtage drop. Reverse the probes to check for open circuit.

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.

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.

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:

| Funció | Interval | Resolució | Precisió |
|---|---|---|---|
| DC Voltage | 60mV/600V/6V/60V/600V | 0.1 V | ± 0.5% ± 5 |
| Vol. ACtage | 60mV/600V/6V/60V/600V | 0.1 V | ± 0.4% ± 5 |
| Corrent continu | 600uA/6000uA/60mA/600mA/6A/10A | 0.1 mA | ±1.2%±5 / ±3%±5 |
| Corrent alterna | 600uA/6000uA/60mA/600mA/6A/10A | 0.1 mA | ±1.2%±5 / ±3%±5 |
| Resistent | 600Ω/6kΩ/60kΩ/6MΩ/60MΩ | 0.01 MΩ | ± 0.8% ± 5 |
| Freqüència | 9Hz/99Hz/999Hz/9KHz/99KHz/999KHz/9MHz | 0.001 MHz | ± 1.5% ± 5 |
| Condensadors | 600pF/60nF/600nF/60uF/600uF/60mF/600mF | 0.1 mF | ± 4.0% ± 5 |
| Inductors | 600uH/6mH/60mH/60mH/6H/60H | 10 KΩ | ± 1.0% ± 5 |
| Temp | -55~1000°C | ||
| Tiristor | Sí | ||
| On-off buzzer | Sí | ||
| Retenció de dades | Sí | ||
| Il·luminació de la pantalla | Sí | ||
| NCV | Sí | ||
| Volum baixtage Visualització | Sí | ||
| Apagat automàtic | Sí | ||
| Mode de visualització | 6000 Pantalla | ||
| Dimensions generals | 147 * 71 * 45 mm | ||
| Font d'alimentació | 3x 1.5V AAA battery | ||
| Temperatura de funcionament | -55~1000°C | ||
| Certificació | CE, 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.





