1. Introduction
The Wohler HBF 420 Moisture Meter is a versatile hand-held instrument designed to assess moisture content in various materials. It uniquely combines electrical resistance and dielectric measurement techniques, making it ideal for quickly assessing moisture profiles in building materials and precisely determining moisture content in wood. This manual provides comprehensive instructions for the safe and effective use of your device.
2. Safety Information
Please read all safety instructions carefully before operating the device. Failure to follow these instructions may result in injury or damage to the meter.
- Do not expose the device to extreme temperatures, humidity, or direct sunlight.
- Keep the device away from strong magnetic fields.
- Do not attempt to open or repair the device yourself. Refer all servicing to qualified personnel.
- Ensure the measurement pins are clean and free from debris before use.
- Handle the measurement pins with care to avoid injury.
- Dispose of batteries according to local regulations.
3. Product Overview
The Wohler HBF 420 is designed for ease of use and accurate measurements. Key features include:
- Dual measurement techniques: Dielectric for quick assessment and Resistance for precise wood moisture.
- Automatic temperature compensation for accurate readings.
- Clear digital display.
Figure 3.1: Wohler HBF 420 Moisture Meter. This image shows the blue meter with its protective cap removed, revealing the digital display, control buttons (SET, M, power), and the two sharp measurement pins at the bottom. The display shows "16".
Figure 3.2: Using the Wohler HBF 420 Moisture Meter. A hand is shown holding the blue meter against a concrete surface, demonstrating its application for measuring moisture in building materials. The display shows "8.9".
4. Setup
4.1 Battery Installation
The Wohler HBF 420 requires 4 AAA batteries for operation.
- Locate the battery compartment cover on the back of the device.
- Slide or unclip the cover to open the compartment.
- Insert 4 AAA batteries, ensuring correct polarity (+/-) as indicated inside the compartment.
- Replace the battery compartment cover securely.
4.2 Initial Power On
Press the power button (⏻) to turn on the device. The display will illuminate and show a brief startup sequence.
5. Operating Instructions
5.1 Selecting Measurement Mode
The HBF 420 supports two primary measurement techniques:
- Dielectric Measurement: For quick assessment of moisture in building materials. This mode uses the sensor on the back of the device.
- Resistance Measurement: For precise determination of moisture content in wood using the integrated pins.
Use the M button to toggle between measurement modes. The display will indicate the active mode.
5.2 Taking a Measurement
- For Dielectric Measurement: Place the back of the device flat against the surface of the material you wish to measure. Ensure full contact. The reading will appear on the display.
- For Resistance Measurement (Wood): Carefully press the two measurement pins into the wood surface. Ensure both pins penetrate the material. The moisture content will be displayed.
- Read the value on the digital display.
5.3 Temperature Compensation
For accurate resistance measurements in wood, the device offers automatic temperature compensation. Enter the material temperature using the SET button and navigation controls (if available, based on typical Wohler interfaces, assuming the SET button is for settings/calibration). Refer to the on-screen prompts for specific temperature input procedures.
5.4 Alarm Function
The device features an alarm function (indicated by "ALARM" on the device). Consult the device's on-screen menu or specific button functions to set or adjust alarm thresholds for moisture levels.
6. Maintenance
6.1 Cleaning
Wipe the device with a soft, dry cloth. Do not use abrasive cleaners or solvents. Ensure the measurement pins are clean and free of residue after each use.
6.2 Storage
When not in use, store the Wohler HBF 420 in a cool, dry place, away from direct sunlight and extreme temperatures. If storing for extended periods, remove the batteries to prevent leakage.
7. Troubleshooting
| Problem | Possible Cause | Solution |
|---|---|---|
| Device does not power on. | Dead or incorrectly installed batteries. | Check battery polarity; replace batteries. |
| Inaccurate readings. | Poor contact with material; dirty pins; incorrect mode. | Ensure full contact; clean pins; verify correct measurement mode. |
| Display is blank or flickering. | Low battery; internal error. | Replace batteries. If problem persists, contact support. |
8. Specifications
| Attribute | Detail |
|---|---|
| Product Dimensions | 7.87 x 3.15 x 2.36 inches |
| Item Weight | 6.4 ounces |
| Item Model Number | 8440 |
| Batteries | 4 AAA batteries required |
| Manufacturer | Wohler |
| Country of Origin | Germany |
| Mounting Type | Tabletop |
9. Warranty and Support
For warranty information and technical support, please contact Wohler customer service directly. Refer to the product packaging or the official Wohler website for contact details.
Wohler Website: www.wohler.com
