1. Introducció
The PeakTech P 4090 is a high-precision True RMS Bench Multimeter designed for accurate electrical measurements in various applications. This versatile device offers a comprehensive range of functions, including True RMS measurement, diode and continuity testing, and relative value measurement. Featuring a clear 21mm LCD display, it ensures quick and easy reading of measured values. The integrated USB interface and accompanying PC software enable convenient data logging, analysis, and remote control, making it suitable for both laboratory and mobile service use.

Figura 1: Frontal view of the PeakTech P 4090 True RMS Bench Multimeter.
2. Informació de seguretat
Always read this manual thoroughly before operating the PeakTech P 4090 Multimeter. Failure to follow safety instructions can result in electric shock, fire, or damage to the device. Keep this manual for future reference.
- The device complies with safety standard EN 61010-1 and is rated CAT I 600V.
- To prevent electrical shock, always remove test leads and the power cord before opening the battery cover or the device casing.
- Do not operate the multimeter with the battery cover open.
- To prevent fire, install only fuses with the specified ampera i voltage ratings (F 200mA/250V and 10A/MAX).
- Ensure the operating environment is dry and free from excessive dust or corrosive gases.
- Do not use the device if it appears damaged or if the insulation of the test leads is compromised.

Figure 2: Rear panel of the multimeter showing power input, USB port, and safety warnings.
3. Contingut del paquet
Upon unpacking your PeakTech P 4090 Multimeter, please verify that all the following items are present and in good condition:
- PeakTech P 4090 True RMS Bench Multimeter
- Maleta de transport
- Cable d'alimentació
- Cable d'interfície USB
- Programari per a Windows
- Test leads (red and black)
- Manual d'instruccions
4. Producte acabatview
4.1 Tauler frontal

Figura 3: Detall frontal view showing the LCD display, rotary switch, input jacks, and function buttons.
The front panel features the large 21mm LCD display, a central rotary switch for function selection, input jacks for test leads, and various push-buttons for additional functions.
- Pantalla LCD: Shows measurement values, units, and function indicators.
- Preses d'entrada: Dedicated terminals for voltage (V), current (10A, µA mA), and common (COM) connections.
- Interruptor rotatiu: Used to select the desired measurement function (e.g., DC Voltage, AC Voltage, Resistance, Current, Frequency, Temperature).
- Botons de funció: Include RANGE, HOLD, REL (Relative), MAX/MIN, Hz/Duty, USB, MODE, and Backlight control.
4.2 Panell posterior

Figure 4: Rear panel with power input, battery compartment, and USB interface.
The rear panel provides connections for power and data communication.
- Entrada d'alimentació: AC power socket (220V 50Hz) and DC battery compartment (6 x 1.5V R14C UM2).
- Port USB: For connecting the multimeter to a computer for data transfer and software control.
- Interruptor d'alimentació: Interruptor principal d'alimentació del dispositiu.
4.3 Suport inclinable

Figura 5: lateral view illustrating the adjustable tilt stand for optimal viewangle de ing.
An integrated tilt stand on the underside of the multimeter allows for adjusting the viewing angle for improved ergonomics and readability.
5. Configuració
5.1 Powering the Multimeter
The PeakTech P 4090 can be powered by either AC mains or batteries for mobile use.
5.1.1 Instal·lació de la bateria
- Ensure the multimeter is turned off and disconnected from any power source and test leads.
- Locate the battery compartment on the rear panel (refer to Figure 4).
- Desenrosqueu la tapa del compartiment de la bateria i traieu-la.
- Insert six (6) 1.5V R14C (UM2) batteries, observing the correct polarity (+/-).
- Replace the battery compartment cover and secure it with screws.
5.1.2 Connexió d'alimentació CA
- Assegureu-vos que el multímetre estigui apagat.
- Connect the provided power cord to the AC power input socket on the rear panel (refer to Figure 4).
- Plug the other end of the power cord into a suitable 220V 50Hz AC outlet.
5.2 Connexió dels cables de prova
Always connect the test leads to the appropriate input jacks based on the measurement you intend to perform. Incorrect connection can lead to damage or inaccurate readings.
- Per a la majoria de volumstage, resistance, continuity, and diode measurements, connect the red test lead to the 'V Ω Temp' jack and the black test lead to the 'COM' jack.
- For current measurements up to 250mA, connect the red test lead to the 'µA mA' jack and the black test lead to the 'COM' jack.
- For high current measurements up to 10A, connect the red test lead to the '10A' jack and the black test lead to the 'COM' jack.
5.3 Software Installation (for Windows)
The PeakTech P 4090 includes PC software for data logging and analysis. Follow these steps to install:
- Insert the provided software CD into your computer's CD/DVD drive.
- Follow the on-screen instructions to install the software. If the installer does not launch automatically, browse the CD and run the setup file.
- After installation, connect the multimeter to your computer using the supplied USB interface cable (refer to Figure 4 for USB port location).
- Launch the PeakTech DMM Tool software to begin data communication.

Figura 6: Example screenshot of the PeakTech DMM Tool software interface.
6. Instruccions de funcionament
6.1 Encès/Apagat
To turn the multimeter on, flip the power switch on the rear panel to the 'ON' position. To turn it off, flip the switch to 'OFF'.
6.2 Selecció de la funció
Rotate the central rotary switch on the front panel to select the desired measurement function. The selected function will be indicated on the LCD display.
- V (DC/AC Voltage): For measuring direct or alternating current voltage.
- 10A (DC/AC Current): For measuring high direct or alternating current.
- mV Hz Ω Temp (Millivolt, Frequency, Resistance, Temperature): A multi-function setting. Use the MODE button to cycle through these functions.
- µA mA (DC/AC Current): For measuring low direct or alternating current.
- Hz/Duty (°C/°F): For measuring frequency/duty cycle or temperature in Celsius/Fahrenheit. Use the MODE button to switch.
6.3 Funcions dels botons
- GAMMA: Manually selects the measurement range. Press repeatedly to cycle through available ranges. Hold to return to auto-ranging.
- MANTENIR: Congela la lectura actual de la pantalla. Premeu de nou per alliberar-la.
- REL (Relatiu): Stores the current reading as a reference and displays subsequent measurements as a deviation from this reference.
- MÀXIM / MÍN: Records and displays the maximum and minimum values measured since activation.
- Hz/Funció: In relevant functions, toggles between frequency and duty cycle measurement.
- USB: Activates or deactivates the USB communication interface.
- Mode: Cycles through sub-functions within a rotary switch setting (e.g., DC/AC, Resistance/Continuity/Diode, Hz/Temp).
- Botó de retroil·luminació: Activa o desactiva la retroiluminació de la pantalla.
6.4 Basic Measurement Procedures
Always ensure the multimeter is set to the correct function and range, and test leads are connected properly before making any measurements.
- Voltage Measurement (DC/AC):
a. Connect the red lead to 'V Ω Temp' and the black lead to 'COM'.
b. Set the rotary switch to 'V' (for DC or AC voltage). Use the MODE button to select DC or AC.
c. Connect the test leads in parallel to the circuit or component to be measured. - Current Measurement (DC/AC):
a. Connect the red lead to 'µA mA' or '10A' (depending on expected current) and the black lead to 'COM'.
b. Set the rotary switch to 'µA mA' or '10A'. Use the MODE button to select DC or AC.
c. Connect the multimeter in series with the circuit to be measured. - Mesura de la resistència:
a. Connect the red lead to 'V Ω Temp' and the black lead to 'COM'.
b. Set the rotary switch to 'mV Hz Ω Temp'. Press MODE until 'Ω' is displayed.
c. Connect the test leads across the component to be measured (ensure power is off for passive components). - Prova de continuïtat:
a. Connect the red lead to 'V Ω Temp' and the black lead to 'COM'.
b. Set the rotary switch to 'mV Hz Ω Temp'. Press MODE until the continuity symbol (speaker icon) is displayed.
c. Touch the test leads to the points to be tested. A beep indicates continuity. - Prova de díode:
a. Connect the red lead to 'V Ω Temp' and the black lead to 'COM'.
b. Set the rotary switch to 'mV Hz Ω Temp'. Press MODE until the diode symbol is displayed.
c. Connect the test leads across the diode. The display will show the forward voltage gota.
7. Manteniment
7.1 Neteja
Per netejar el multímetre, netegeu la carcassa amb aiguaamp cloth and a mild detergent. Do not use abrasives or solvents. Ensure the device is powered off and disconnected from all circuits and power sources before cleaning.
7.2 Substitució de la bateria
When the low battery indicator appears on the display, replace the batteries promptly to ensure accurate measurements. Follow the steps outlined in Section 5.1.1 for battery installation.
7.3 Canvi de fusibles
If the current measurement function fails, the fuse may need replacement. Always replace fuses with the correct type and rating to prevent damage and ensure safety.
- Ensure the multimeter is turned off and disconnected from all power sources and test leads.
- Locate the fuse compartment, typically accessible by opening the main casing (refer to safety warnings in Section 2). This procedure should only be performed by qualified personnel.
- Replace the blown fuse with a new one of the identical type and rating:
- For µA/mA input: F 200mA/250V, Ø 5x20mm
- For 10A input: F 10A/MAX, 10 sec MAX EACH 15min (specific fuse type may vary, refer to device markings)
- Tanqueu bé la casing before resuming operation.
8. Solució De Problemes
If you encounter issues with your PeakTech P 4090 Multimeter, refer to the following common troubleshooting steps:
- Sense pantalla/alimentació: Check if the power switch is ON. If using batteries, check battery charge and polarity. If using AC, ensure the power cord is securely connected and the outlet is functional.
- Lectures incorrectes: Ensure test leads are correctly connected to the appropriate input jacks for the selected function. Verify the rotary switch is set to the correct measurement type and range. Check if the REL function is active.
- La mesura actual no funciona: The fuse for the current input may be blown. Refer to Section 7.3 for fuse replacement instructions.
- No USB Communication: Ensure the USB button on the multimeter is activated. Check USB cable connection and PC software installation. Restart the software and/or computer.
- Lectures intermitents: Check for loose connections at the test leads or input jacks. Ensure the test leads are not damaged.
Si el problema persisteix després d'intentar aquests passos, poseu-vos en contacte amb l'atenció al client o amb un tècnic de servei qualificat.
9. Especificacions
| Característica | Especificació |
|---|---|
| Model | P 4090 |
| Mostra | 21mm LCD, 22,000 counts |
| Tipus de mesura | RMS veritable |
| Classificació de seguretat | EN 61010-1; CAT I 600V |
| Entrada d’alimentació de CA. | 200 ~ 240V AC / 50Hz |
| Entrada d'alimentació de CC | 6 x 1.5V R14C (UM2) batteries |
| Temperatura de funcionament | -20 °C a +100 °C |
| Interval de freqüència | 20Hz - 220MHz |
| Dimensions (L x A x A) | 32 x 27 x 10 cm |
| Pes | 2.8 kg |
| Connectivitat | Interfície USB |
| Fabricant | PeakTech |
| UPC | 042505694025 |
10. Garantia i Suport
For warranty information, technical support, or service inquiries, please contact PeakTech directly. Refer to the official PeakTech weblloc web per obtenir les dades de contacte i els termes de garantia més actualitzats.
Fabricant: PeakTech
Weblloc: www.peaktech.de