1. Introduction
This manual provides instructions for the safe and effective operation of your BLACK+DECKER BDMU040 Ultrasonic Range Meter. Please read these instructions carefully before use and retain them for future reference.
The BDMU040 is designed for measuring distances up to 12 meters, and calculating surface areas and volumes. It is an ideal tool for various household and professional tasks, such as estimating material quantities for painting or flooring.
2. Safety Instructions
- Battery Safety: The device requires a 9V battery (not included). Ensure correct polarity when inserting. Remove the battery if the device will not be used for an extended period.
- Ultrasonic Emissions: This device emits ultrasonic waves. While generally safe, avoid directing the sensor directly at eyes or ears for prolonged periods.
- Environmental Conditions: Do not expose the device to extreme temperatures, humidity, or direct sunlight. The device has an IP54 rating, indicating protection against dust and splashing water, but it is not fully waterproof.
- Cleaning: Clean the device with a soft, dry cloth. Do not use abrasive cleaners or solvents.
- Repairs: Do not attempt to open or repair the device yourself. Refer all servicing to qualified personnel.
3. Product Components
Familiarize yourself with the main parts of your ultrasonic range meter:

Image 1: Front view of the BLACK+DECKER BDMU040 Ultrasonic Range Meter. The image displays the LCD screen at the top, showing measurement readings. Below the screen are several buttons: two function selection buttons (for length/width and volume/area), a 'READ' button with a power symbol, a '+/=' button, a 'UNITS' button, and a 'CLEAR' button. The lower part of the device features the 'BLACK+DECKER' logo on an orange panel.
- LCD Display: Shows measurements, units, and mode indicators.
- Ultrasonic Sensor: Located at the top of the device, emits and receives ultrasonic waves.
- Function Buttons: Select measurement modes (length, area, volume).
- READ / Power Button: Activates measurement and turns the device on/off.
- UNITS Button: Changes measurement units (e.g., meters, feet).
- CLEAR Button: Clears current measurements or selections.
- Add/Subtract Button (+/=): Used for adding or subtracting measurements.
- Battery Compartment: Located on the back (not visible in image), holds the 9V battery.
4. Setup
4.1. Installing the Battery
- Locate the battery compartment cover on the back of the device.
- Slide or unclip the cover to open it.
- Insert one 9V alkaline battery, ensuring the correct polarity (+ and - terminals match the markings inside the compartment).
- Replace the battery compartment cover securely.
Note: A 9V battery is not included with the device and must be purchased separately.
5. Operating Instructions
5.1. Powering On/Off
- To turn on the device, press the READ button. The LCD display will illuminate.
- The device will automatically power off after approximately 30 seconds of inactivity to conserve battery life. To manually turn off, press and hold the READ button for a few seconds.
5.2. Changing Measurement Units
- With the device powered on, press the UNITS button to cycle through available measurement units (e.g., meters, feet, inches). The selected unit will be displayed on the LCD.
5.3. Measuring Distance
- Ensure the device is in single distance measurement mode (indicated by a single line on the display). If not, press the appropriate function button to select it.
- Hold the device firmly, ensuring the ultrasonic sensor at the top is pointed directly at the target surface. Avoid obstacles between the device and the target.
- Press the READ button. The device will emit an ultrasonic pulse.
- The measured distance will be displayed on the LCD screen.
Tip: For best accuracy, hold the device perpendicular to the target surface and ensure the path is clear.
5.4. Measuring Area
- Press the function button that displays the area icon (typically a rectangle). The display will prompt for length (L) and width (W).
- Measure the length of the area by pointing the device and pressing READ. The length value will be stored.
- Measure the width of the area by pointing the device and pressing READ again. The width value will be stored.
- The device will automatically calculate and display the area (L x W) on the LCD.
5.5. Measuring Volume
- Press the function button that displays the volume icon (typically a cube). The display will prompt for length (L), width (W), and height (H).
- Measure the length by pointing the device and pressing READ.
- Measure the width by pointing the device and pressing READ.
- Measure the height by pointing the device and pressing READ.
- The device will automatically calculate and display the volume (L x W x H) on the LCD.
5.6. Adding/Subtracting Measurements
- After taking a measurement, press the +/= button. The current measurement will be added to a running total.
- To subtract, some models may require pressing the +/= button twice or holding it. Refer to the display for specific indicators.
- To view the total, press the +/= button again after all desired measurements are entered.
- Press CLEAR to reset the total.
5.7. Clearing Measurements
- Press the CLEAR button to clear the last measurement or calculation result from the display.
- Pressing CLEAR multiple times may clear previous entries or reset the device to default measurement mode.
6. Maintenance
6.1. Cleaning
Wipe the device with a soft, dry, or slightly damp cloth. Do not use harsh chemicals, cleaning solvents, or strong detergents. Ensure the ultrasonic sensor is free from dust and debris for accurate readings.
6.2. Storage
When not in use, store the device in a cool, dry place, away from direct sunlight and extreme temperatures. If storing for an extended period, remove the 9V battery to prevent leakage.
6.3. Battery Replacement
Replace the 9V battery when the low battery indicator appears on the LCD display or if the device fails to power on. Follow the battery installation steps in Section 4.1.
7. Troubleshooting
| Problem | Possible Cause | Solution |
|---|---|---|
| Device does not turn on. | Battery is dead or incorrectly inserted. | Check battery polarity. Replace with a new 9V battery. |
| Inaccurate measurements. |
|
|
| Display shows "Error" or "Out of Range". | Target is too close, too far, or signal is obstructed. | Ensure target is within the 0.6m to 12m range. Clear obstructions. |
8. Specifications
| Model: | BDMU040 |
| Brand: | BLACK+DECKER |
| Measurement Technology: | Ultrasonic |
| Measuring Range: | Approximately 0.6 m to 12 m (2 ft to 39 ft) |
| Accuracy: | Typically ±0.5% (depending on conditions) |
| Functions: | Distance, Area, Volume, Addition/Subtraction |
| Units: | Meters (m), Feet (ft), Inches (in) |
| Battery Type: | 1 x 9V (Alkaline recommended, not included) |
| Automatic Shut-off: | Approx. 30 seconds of inactivity |
| Ingress Protection (IP) Rating: | IP54 (Dust protected, splash proof) |
| Dimensions (approx.): | 24.4 x 13.6 x 4 cm |
| Weight (approx.): | 180 g (without battery) |
9. Warranty and Support
For warranty information, technical support, or service inquiries, please refer to the official BLACK+DECKER website or contact their customer service department in your region. Keep your proof of purchase for warranty claims.
Online Resources: www.blackanddecker.com