Introducere
The Metrel MD 9040 is a True RMS (TRMS) industrial digital multimeter designed for demanding applications in the industrial sector. It features a CAT IV / 1000 V overvoltage category rating, ensuring safety and reliability for measurements on power supply sources. This device offers high accuracy, a 2-line LCD display, and various measurement functions for versatile use.

Figura 1: The Metrel MD 9040 TRMS Industrial Digital Multimeter, showcasing its robust design and clear display.
Caracteristici cheie
The MD 9040 incorporates several features designed for precision and user convenience:
- TRMS: Provides accurate readings for both sinusoidal and non-sinusoidal AC signals.
- Lead Alert: An audible and visual warning system for incorrect test lead connections, enhancing safety.
- Auto-range: Automatically selects the appropriate measurement range, with an option to switch to manual ranging.
- Relative Zero Mode: Allows for comparison of signal differences or removal of background noise by setting a reference point.
- Păstrarea datelor: Freezes the current measurement on the display for convenient recording.
- Link PC: Enables connection to a personal computer for data logging and analysis using optional software and interface.
- Siguranţă: Rated CAT IV / 1000 V for high-level overvoltage protection, suitable for industrial environments.
- Afişa: Features a large, bright 4-digit, 9999 counts dual LCD display for clear readability.

Figura 2: Un pesteview highlighting the key features, measuring functions, and typical applications of the MD 9040 multimeter.
Înființat
Instalarea bateriei
The MD 9040 is powered by a 9V battery. To install or replace the battery, locate the battery compartment on the rear of the device. Open the compartment, insert the 9V battery ensuring correct polarity, and then securely close the cover. Always replace the battery when the low battery indicator appears on the display to maintain measurement accuracy.
Conexiune cablu de testare
Connect the test leads to the appropriate input jacks on the multimeter's front panel. The device features a lead alert system to indicate incorrect connections, enhancing user safety. Refer to the following guidelines:
- Pentru voltage, resistance, capacitance, diode, and continuity measurements, connect the red test lead to the VΩHz mufa și cablul negru de testare la COM jack.
- Pentru current measurements (mA µA), connect the red test lead to the mA pA mufa și cablul negru de testare la COM jack.
- Pentru high current measurements (up to 10A), connect the red test lead to the 10A mufa și cablul negru de testare la COM jack.

Figura 3: A închide view of the MD 9040's front panel, showing the rotary switch, display, and input jacks for test lead connections.
Instrucțiuni de operare
Pornire/Oprire
To power on the MD 9040, rotate the central function switch from the OFF position to the desired measurement function. To power off the device, rotate the switch back to the OFF poziţie.
Funcții de măsurare
The MD 9040 offers a comprehensive range of measurement capabilities:
- Voltage (AC/DC): Selecta V~ pentru AC voltage sau V- pentru DC voltage măsurători.
- Curent (AC/DC): Selecta A~ pentru curent alternativ sau A- for DC current measurements. Ensure the test leads are connected to the appropriate current input jacks (mA µA or 10A).
- Rezistență (Ω): Selectați Ω position for resistance measurements.
- Capacitate (F): Selectați F position for capacitance measurements.
- Test de diodă: Select the diode symbol for testing diodes.
- Test de continuitate: Select the continuity symbol for checking circuit continuity, indicated by an audible tone.
- Frecvența (Hz): Selectați Hz position for frequency measurements.
Auto-Ranging and Manual Ranging
The multimeter defaults to auto-ranging, which automatically selects the most suitable measurement range. To switch to manual ranging, press the GAMA button. In manual ranging, press GAMA repeatedly to cycle through available ranges. To return to auto-ranging, press and hold the GAMA buton.
Mod relativ zero
Apăsați tasta REL button to activate relative zero mode. This function subtracts the current displayed reading from all subsequent measurements, which is useful for comparing values or nulling out background noise. Press REL din nou pentru a ieși din acest mod.
Reținere de date
Apăsați tasta ȚINE button to freeze the current reading on the display. This allows for convenient recording of measurements. Press ȚINE again to release the display and resume live readings.
Întreţinere
Înlocuirea bateriei
When the low battery indicator appears on the display, replace the 9V battery promptly to ensure continued accurate operation. Refer to the 'Setup' section for detailed battery installation instructions.
Curatenie
To clean the multimeter casing, folosește un d moaleamp cloth. Avoid using abrasive cleaners, solvents, or harsh chemicals, as these can damage the device. Ensure the multimeter is powered off and disconnected from any electrical circuits before cleaning.
Depozitare
Store the MD 9040 in a dry, cool environment, away from direct sunlight, extreme temperatures, and high humidity. If the device will not be used for an extended period, it is recommended to remove the battery to prevent potential leakage and damage.
Depanare
This section addresses common issues you might encounter with your MD 9040 multimeter.
- Fără afișaj/alimentare: Check the battery charge level and ensure the 9V battery is correctly installed with proper polarity.
- Citiri inexacte: Verify that the correct measurement function is selected on the rotary switch. Ensure test leads are properly connected to the correct input jacks and that the battery is not low.
- Lead Alert Warning: If the lead alert activates, recheck all test lead connections to ensure they are inserted into the appropriate input jacks for the selected measurement function.
- Afișajul arată „OL” (Suprasarcină): This indicates that the measured value exceeds the currently selected range. Switch to a higher measurement range or ensure the input signal is within the device's specified limits.
Specificatii tehnice
The Metrel MD 9040 TRMS Industrial Digital Multimeter adheres to the following technical specifications:
| Funcţie | Gamă | Precizie |
|---|---|---|
| AC Voltage (40 Hz - 20 kHz) | 60.00 mV - 999.9 V | ±(0.5% of reading + 3 digits) to ±(3.0% of reading + 4 digits) |
| DC Voltage | 60.00 mV - 999.9 V | ±(0.06% of reading + 2 digits) to ±(0.1% of reading + 2 digits) |
| Curent DC | 600.0 µA - 10.00 A | ±(0.2% din citire + 4 cifre) |
| Curent AC TRMS | 600.0 µA - 10.00 A | from ±(0.6% of reading + 3 digits) to ±(1.0% of reading + 3 digits) |
| Testul diodei | 2.000 V | ±(1.0% of reading + 1 digit) |
| Rezistenţă | 600.0 Ω - 60.00 MΩ | from ±(0.1% of reading + 3 digits) to ±(1.0% of reading + 5 digits) |
| Frecvența rețelei | 15.00 Hz - 50.00 Hz | ±(0.04% din citire + 4 cifre) |
| Frequency of digital equipment | 5.00 Hz - 1.000 MHz | ±(0.004% din citire + 4 cifre) |
| Capacitate | 60.00 nF - 29.99 mF | from ±(1.0% of reading + 5 digits) to ±(5.0% of reading + 5 digits) |
- Sursa de alimentare: 9V Battery (NEDA1604C, JIS006P, or IEC6F22)
- Overvoltage Categorie: CAT IV / 1000V
- Dimensiuni: 207 x 96 x 55 mm
- Greutate: 635 g

Figura 4: Detailed technical specifications table for the Metrel MD 9040, including functions, ranges, and accuracy.
Garanție și suport
Informații despre garanție
The Metrel MD 9040 TRMS Industrial Digital Multimeter is covered by a 2-year (24-month) manufacturer's warranty from the date of purchase. Please retain your original purchase receipt as proof of purchase for any warranty claims. The warranty covers defects in materials and workmanship under normal use.
Asistență pentru clienți
For technical assistance, service, or further information regarding your MD 9040 multimeter, please contact Metrel customer support. You can find contact details and additional resources on the official Metrel website. When contacting support, please have your product model and serial number available.





