Introduction
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.
Figure 1: The Metrel MD 9040 TRMS Industrial Digital Multimeter, showcasing its robust design and clear display.
Key Features
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-ranging: 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.
- Data Hold: Freezes the current measurement on the display for convenient recording.
- PC Link: Enables connection to a personal computer for data logging and analysis using optional software and interface.
- Safety: Rated CAT IV / 1000 V for high-level overvoltage protection, suitable for industrial environments.
- Display: Features a large, bright 4-digit, 9999 counts dual LCD display for clear readability.
Figure 2: An overview highlighting the key features, measuring functions, and typical applications of the MD 9040 multimeter.
Setup
Battery Installation
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.
Test Lead Connection
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:
- For voltage, resistance, capacitance, diode, and continuity measurements, connect the red test lead to the VΩHz jack and the black test lead to the COM jack.
- For current measurements (mA µA), connect the red test lead to the mA µA 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.
Figure 3: Close-up view of the MD 9040's front panel, showing the rotary switch, display, and input jacks for test lead connections.
Operating Instructions
Power On/Off
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 position.
Measurement Functions
The MD 9040 offers a comprehensive range of measurement capabilities:
- Voltage (AC/DC): Select V~ for AC voltage or V- for DC voltage measurements.
- Current (AC/DC): Select A~ for AC current or A- for DC current measurements. Ensure the test leads are connected to the appropriate current input jacks (mA µA or 10A).
- Resistance (Ω): Select the Ω position for resistance measurements.
- Capacitance (F): Select the F position for capacitance measurements.
- Diode Test: Select the diode symbol for testing diodes.
- Continuity Test: Select the continuity symbol for checking circuit continuity, indicated by an audible tone.
- Frequency (Hz): Select the 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 RANGE button. In manual ranging, press RANGE repeatedly to cycle through available ranges. To return to auto-ranging, press and hold the RANGE button.
Relative Zero Mode
Press the 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 again to exit this mode.
Data Hold
Press the HOLD button to freeze the current reading on the display. This allows for convenient recording of measurements. Press HOLD again to release the display and resume live readings.
Maintenance
Battery Replacement
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.
Cleaning
To clean the multimeter casing, use a soft, damp 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.
Storage
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.
Troubleshooting
This section addresses common issues you might encounter with your MD 9040 multimeter.
- No Display/Power: Check the battery charge level and ensure the 9V battery is correctly installed with proper polarity.
- Inaccurate Readings: 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.
- Display Shows "OL" (Overload): 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.
Technical Specifications
The Metrel MD 9040 TRMS Industrial Digital Multimeter adheres to the following technical specifications:
| Function | Range | Accuracy |
|---|---|---|
| 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) |
| DC Current | 600.0 µA - 10.00 A | ±(0.2% of reading + 4 digits) |
| TRMS AC Current | 600.0 µA - 10.00 A | from ±(0.6% of reading + 3 digits) to ±(1.0% of reading + 3 digits) |
| Diode Test | 2.000 V | ±(1.0% of reading + 1 digit) |
| Resistance | 600.0 Ω - 60.00 MΩ | from ±(0.1% of reading + 3 digits) to ±(1.0% of reading + 5 digits) |
| Mains Frequency | 15.00 Hz - 50.00 Hz | ±(0.04% of reading + 4 digits) |
| Frequency of digital equipment | 5.00 Hz - 1.000 MHz | ±(0.004% of reading + 4 digits) |
| Capacitance | 60.00 nF - 29.99 mF | from ±(1.0% of reading + 5 digits) to ±(5.0% of reading + 5 digits) |
- Power Source: 9V Battery (NEDA1604C, JIS006P, or IEC6F22)
- Overvoltage Category: CAT IV / 1000V
- Dimensions: 207 x 96 x 55 mm
- Weight: 635 g
Figure 4: Detailed technical specifications table for the Metrel MD 9040, including functions, ranges, and accuracy.
Warranty and Support
Warranty Information
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.
Customer Support
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.
