1. Introducció
The Proster T21D is a high-precision, high-performance 6000 counts digital multimeter designed for a wide range of electrical measurements. This versatile tool is suitable for both professional technicians and home users, offering reliable readings for various parameters. Its compact design, clear display, and robust construction make it an essential device for electrical testing and troubleshooting.
2. Informació de seguretat
Always read and understand all safety warnings and operating instructions before using this instrument. Failure to observe safety precautions can result in electric shock, fire, or injury.
- No supereu els valors d'entrada màxims especificats per a cada rang de mesura.
- Aneu amb extrema precaució quan treballeu amb voltages above 36V DC or 25V AC RMS, as these can pose a shock hazard.
- Ensure the test leads are in good condition, without any damage or exposed wiring.
- Desconnecteu sempre l'alimentació del circuit que s'està provant abans de connectar o desconnectar els cables de prova, especialment quan mesureu el corrent.
- Do not operate the multimeter if it appears damaged or if the protective casins'elimina g.
- Canvieu les piles immediatament quan aparegui l'indicador de bateria baixa per garantir lectures precises.
- This device is rated for CAT III 600V, meaning it is suitable for measurements in building installations (e.g., 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, e.g., stationary motors with permanent connection to the fixed installation).
3. Contingut del paquet
En obrir el paquet, comproveu que hi hagi tots els elements següents:
- Proster 6000 Counts Digital Multimeter (Model T21D)
- Pair of Test Probes (Red and Black)
- Sonda de temperatura
- Manual d'usuari
- Clip d'aligator
- Tornavís
- 3 piles AAA d'1.5 V (preinstal·lades o incloses per separat)
- 2 fusibles (de recanvi)

Image: Contents of the Proster Digital Multimeter package, including the multimeter, test leads, temperature probe, and other accessories.
4. Producte acabatview
The Proster T21D Digital Multimeter features a robust design with a clear, backlit LCD display for easy reading in various lighting conditions. It includes a kickstand for convenient tabletop use and a magnetic back for attachment to metal surfaces.

Imatge: Frontal view of the Proster Digital Multimeter, showing the display, rotary dial, function buttons, and input jacks, along with the included test leads.

Image: An illustration highlighting the key features of the multimeter, including AC/DC voltage, current, frequency, resistance, temperature, duty cycle, capacitance, diode, continuity, data hold, and NCV functions.

Image: Close-up of the multimeter's large, backlit LCD display, demonstrating its readability from various angles, especially in low-light conditions.

Imatge: Una explosió view of the multimeter, illustrating its internal intelligent protection circuit board with built-in double safety fuses, designed to prevent overload damage.
5. Configuració
5.1 Instal·lació de la bateria
The multimeter requires 3 AAA 1.5V batteries for operation. These are typically included in the package. To install or replace batteries:
- Assegureu-vos que el multímetre estigui APAGAT.
- Localitzeu el compartiment de la bateria a la part posterior de la unitat.
- Feu servir el tornavís inclòs per afluixar el cargol que fixa la tapa de la bateria.
- Traieu la tapa de la bateria.
- Introduïu les 3 piles AAA, observant la polaritat correcta (+/-) tal com s'indica a l'interior del compartiment.
- Col·loqueu la tapa de la bateria i premeu el cargol amb seguretat.
5.2 Connexió dels cables de prova
For most measurements, the test leads will be connected to the 'COM' (Common, black lead) and 'VΩmAHz' (red lead) input jacks. For high current measurements (up to 10A), the red lead should be connected to the '10A' input jack.
- Inseriu el cable de prova negre al connector 'COM' (comú).
- Insert the red test lead into the appropriate jack for your measurement:
- 'VΩmAHz' for Voltage, Resistance, Capacitance, Frequency, Diode, Continuity, and small Current measurements (mA).
- '10A' for high Current measurements (up to 10A).
6. Instruccions de funcionament
The Proster T21D offers a wide range of measurement functions. Use the rotary dial to select the desired measurement mode.
6.1 Mesures bàsiques
- VoltagMesura (CA/CC):
Gireu el selector rotatiu a la posició 'V~' (Volum ACtage) o 'V=' (Volum de CCtage) position. Connect the test leads in parallel to the circuit or component. The multimeter will automatically select the range. - Mesura de corrent (CA/CC):
Turn the rotary dial to the 'A~' (AC Current) or 'A=' (DC Current) position. For currents up to 600mA, connect the red lead to 'VΩmAHz'. For currents up to 10A, connect the red lead to '10A'. Connect the multimeter in series with the circuit. - Mesura de la resistència:
Turn the rotary dial to the 'Ω' (Resistance) position. Connect the test leads across the component. Ensure the circuit is de-energized before measuring resistance. - Mesura de la capacitat:
Turn the rotary dial to the '∔' (Capacitance) position. Connect the test leads across the capacitor. Ensure the capacitor is fully discharged before testing. - Mesura de freqüència:
Turn the rotary dial to the 'Hz' (Frequency) position. Connect the test leads to the signal source. - Mesura de la temperatura:
Turn the rotary dial to the '°C/°F' (Temperature) position. Connect the temperature probe to the appropriate input jacks (usually VΩmAHz and COM). Place the probe on or near the object whose temperature is to be measured. - Prova de díode:
Turn the rotary dial to the 'Diode' position. Connect the red lead to the anode and the black lead to the cathode of the diode. The display will show the forward voltagcaiguda electrònica. Invertiu els cables per comprovar si hi ha un circuit obert. - Prova de continuïtat:
Turn the rotary dial to the 'Continuity' position. Connect the test leads across the circuit or component. A continuous beep indicates continuity (low resistance).

Image: A user demonstrating how to measure AC voltage from a power outlet using the Proster Digital Multimeter and its test leads.

Image: A user measuring the resistance of a component on a circuit board using the Proster Digital Multimeter.
6.2 Funcions avançades
- NCV (vol sense contacte).tage) Detecció:
Move the rotary dial to the 'NCV' position. Hold the top of the multimeter near an AC voltage source. The NCV indicator and audible alarm will activate if voltage is detected, providing a non-contact method to identify live wires. - Conservació de dades:
Press the 'HOLD' button to freeze the current reading on the display. Press it again to release. - Retroiluminació/Llanterna:
Press the backlight button (often marked with a light bulb icon) to turn on the display backlight for improved visibility in dim conditions. Some models also integrate a flashlight function activated by the same button or a dedicated one. - RMS veritable:
This multimeter features True RMS measurement, which provides accurate readings for both sinusoidal and non-sinusoidal AC waveforms, unlike average-responding meters.

Imatge: Un cop mésview of the Proster Multimeter's functions and a detailed table of its measurement ranges and precision for various electrical parameters.
7. Manteniment
7.1 Neteja
To clean the multimeter, use a soft cloth dampened with mild detergent. Do not use abrasives or solvents. Ensure the device is completely dry before use.
7.2 Substitució de la bateria
When the low battery indicator appears on the display, replace the batteries as described in Section 5.1. Always use 3 new 1.5V AAA batteries.
7.3 Canvi de fusibles
If the current measurement function stops working, the fuse may be blown. The multimeter includes spare fuses. To replace a fuse:
- Ensure the multimeter is turned OFF and all test leads are disconnected.
- Open the battery compartment cover as described in Section 5.1.
- Carefully remove the old fuse(s). Note the rating of the fuse being replaced.
- Insert a new fuse of the correct type and rating (e.g., F600mA/250V for mA range, F10A/250V for 10A range).
- Torneu a col·locar la tapa de la bateria i premeu el cargol.
8. Solució De Problemes
| Problema | Causa possible | Solució |
|---|---|---|
| Sense pantalla o pantalla tènue | Piles baixes o sense piles instal·lades. | Replace or install new AAA batteries. |
| Lectures incorrectes | Incorrect function selected, poor test lead connection, or out of range. | Verify function selection, ensure secure lead connection, check if measurement is within specified range. |
| La mesura de corrent no funciona | Fusible cremat. | Replace the appropriate fuse (refer to Section 7.3). |
| NCV no detecta el volumtage | Voltage too low, or not an AC voltage. | Assegureu-vos que el voltage source is AC and strong enough for detection. |
9. Especificacions
| Paràmetre | Valor |
|---|---|
| Número de model | T21D |
| Mostra | 6000 recomptes, LCD retroil·luminada |
| DC Voltage Rang | 600mV/6V/60V/600V (Precision: ±(0.5%+5)) |
| Vol. ACtage Rang | 600mV/6V/60V/600V (Precision: ±(1.0%+4)) |
| Interval de corrent DC | 60mA/600mA/10A (Precision: ±(1.2%+5)) |
| Interval de corrent de CA | 60mA/600mA/10A (Precision: ±(1.5%+5)) |
| Interval de resistència | 600Ω/6KΩ/60KΩ/600KΩ/6MΩ/60MΩ (Precision: ±(0.8%+5)) |
| Interval de freqüència | 9.999Hz/99.99Hz/999.9Hz/9.999kHz/99.99kHz/999.9kHz/9.999MHz (Precision: ±(1.5%+5)) |
| Interval de capacitat | 60nF/600nF/6uF/60uF/600uF/6mF/100mF (Precision: ±(4.0%+5)) |
| Interval de temperatura | -20~1000°C / -4~1832°F (Precision: ±(1.0%+3)) |
| RMS veritable | Sí |
| Detecció de NCV | Sí |
| Retenció de dades | Sí |
| Font d'alimentació | 3 piles AAA de 1.5 V |
| Dimensions | 14.7 x 7.1 x 4.5 cm |
| Pes | 220 grams |
| Color | Vermell |
| Classificació de seguretat | CAT III 600V |
| País d'origen | Xina |
10. Garantia i Suport
Proster products are designed for reliability and performance. For any questions, technical assistance, or warranty claims, please contact Proster customer support through the retailer's platform or the official Proster weblloc web. Si us plau, conserveu el comprovant de compra per a finalitats de garantia.
