1. Introduction
The Dr.meter MD918 is a non-destructive, pinless wood moisture meter designed for accurate measurement of moisture content in various wood types and other materials. Utilizing HF electromagnetic waves, it provides readings without damaging the surface of the material. This digital sensor scanner offers a measuring range of 4% to 80% and includes features such as temperature compensation, automatic shut-off, and calibration indication for reliable performance.
Figure 1: Dr.meter MD918 in operation, demonstrating its non-destructive measurement capability.
2. Product Overview
The MD918 meter features an intuitive design with a clear LCD display and easy-to-use buttons. Key components include:
- Wood Density Grader: Indicates the selected wood density setting.
- Moisture Data: Displays the measured moisture percentage.
- Upper Limit Changeover: Allows setting an upper limit for moisture content.
- On/Off Button/Upper Limit Selector: Powers the device on/off and navigates upper limit settings.
- Wood Grade Density Setting: Button to adjust the wood density grade.
- Upper Limit Reading Setting: Button to set the upper limit for moisture readings.
Figure 2: Front panel description of the MD918 meter.
The meter's high-sensitivity inductive probe ensures fast and accurate measurements without causing damage to the material surface.
Figure 3: High-sensitivity inductive probe for non-destructive testing.
3. Setup
Before first use or after battery replacement, it is recommended to calibrate the MD918 meter for accurate readings.
3.1 Battery Installation
The MD918 requires three 1.5V AAA batteries. Open the battery compartment on the back of the device, insert the batteries according to the polarity markings, and close the compartment securely.
3.2 Calibration Procedure
To ensure accurate measurements, especially after changing batteries or if the meter has not been used for a long time, perform the calibration procedure:
- In the off state, remove one battery from the compartment.
- Hold down the "MODE" button. While holding "MODE", re-insert the battery. Release the "MODE" button after the battery is installed.
- The meter will enter calibration mode. The display will show "DENSITY---" and the first "-" will start blinking. Wait for approximately 5 seconds.
- Press the "▼" (down arrow) key. The second "-" will start blinking. Wait for approximately 10 seconds.
Note: Do not place any magnetic or metal objects under the sensor area during calibration. - Turn off the meter to complete the calibration procedure.
- Turn on the meter again. It should now display "0.0%" and be ready for measurement.
Video 1: Detailed steps on how to calibrate the Dr.meter MD918 wood moisture meter.
3.3 Unboxing and Initial Inspection
Upon receiving your Dr.meter MD918, carefully unbox the device and inspect it for any signs of damage. Ensure all included components, such as the carrying pouch and user manual, are present.
Video 2: An unboxing and initial testing demonstration of the Dr.meter MD918 wood moisture meter.
4. Operating Instructions
The MD918 is designed for straightforward operation to measure moisture content in wood and other materials.
4.1 Powering On and Off
Press the "MODE" button to turn the meter on. The device will automatically shut off after 5 minutes of inactivity to conserve battery life.
Figure 4: Automatic shut-off feature for energy saving.
4.2 Selecting Wood Density Grade
Different wood types have varying densities, which affect moisture readings. The MD918 allows you to select from 10 unique grades of timber density to ensure accurate measurements. Refer to the wood density table below to find the appropriate grade for your material.
Press the "DENSITY" button to cycle through the density grades (1-10) until the correct grade for your wood type is displayed.
Figure 5: Wood Density and Grade Selection Table.
4.3 Taking a Measurement
Once the meter is on and the correct wood density grade is selected:
- Place the sensor area (the back of the meter) flat against the surface of the material you wish to measure.
- Ensure full contact between the sensor and the material.
- The moisture content percentage will be displayed on the LCD screen.
For best results, ensure the object to be tested is at a consistent temperature for at least 5 minutes prior to measurement, as the MD918 features temperature compensation for accuracy.
Figure 6: Measuring moisture content with the MD918.
4.4 Applications
The MD918 is suitable for measuring moisture in various materials, including:
- Lumber
- Plank
- Carton
- Wooden Furniture
Figure 7: Wide application of the MD918 moisture meter.
5. Maintenance
Proper care and maintenance will prolong the life and accuracy of your Dr.meter MD918.
- Keep the meter away from water or any corrosive liquid to prevent damage.
- Store the device in a dry, cool place when not in use.
- Clean the exterior with a soft, dry cloth. Do not use abrasive cleaners or solvents.
- Remove batteries if the device will not be used for an extended period to prevent leakage.
6. Troubleshooting
If you encounter issues with your MD918 meter, consider the following:
- Inaccurate or inconsistent readings: Perform a calibration as described in Section 3.2. Ensure the correct wood density grade is selected. Verify that the sensor area is in full contact with the material.
- Meter not turning on: Check battery installation and ensure batteries are not depleted. Replace with fresh batteries if necessary.
- Display shows "0.0" blinking: This indicates the meter may be out of calibration. Follow the calibration procedure in Section 3.2.
- Reading exceeds upper limit: The meter will alert you if the reading surpasses the maximum moisture content ratio it can measure.
- Interference: Keep the meter away from any electrified objects during measurement, as it can be influenced by them.
7. Specifications
| Feature | Specification |
|---|---|
| Measuring Range | 4% ~ 80% |
| Max. Error | ±(1%Rh + 0.5) |
| Resolution | 0.5% |
| Environment Temperature | -10 ~ 60 ℃ |
| Operating Humidity | 0 ~ 70%RH |
| Power Supply | 3 x 1.5V AAA battery |
| Product Dimensions | 5.2"W x 2.64"H |
| Item Weight | 7.2 ounces (0.45 Pounds) |
| Model Number | MD-918 |
Figure 8: Dr.meter MD918 dimensions.
8. Warranty Information
Dr.meter products are designed and manufactured to the highest quality standards. This product is covered by a limited warranty against defects in materials and workmanship. For specific warranty terms and conditions, please refer to the warranty card included with your purchase or contact Dr.meter customer support.
9. Customer Support
For any questions, technical assistance, or support regarding your Dr.meter MD918 Pinless Wood Moisture Meter, please contact our customer service team. Contact information can typically be found on the product packaging, the official Dr.meter website, or through your retailer.