UNI-T UT377A Digital Wood Moisture Meter Instruction Manual

1. Introduction

The UNI-T UT377A is a digital meter specifically designed for measuring the moisture content of various wooden materials, including wood, paper, and plywood. This device incorporates a classification system for wood based on material density, offering four distinct categories, and utilizes a temperature compensation algorithm to ensure high measurement accuracy. Its compact design, energy-efficient operation, and precision make the UT377A an excellent tool for professionals and enthusiasts requiring accurate wood moisture assessment.

Figure 1: Front view of the UT377A Digital Wood Moisture Meter.

Key Features:

• Supports 4 types of wood categories (referencing 28 tree species).
• Automatic ambient temperature compensation for reduced measurement errors.
• Clear LCD display with a refresh rate of 2 times per second.
• Max/Min modes for recording extreme values; Data hold function.
• Low battery indication and LCD backlight for visibility in various conditions.
• Automatic and manual power-off options to conserve battery life.

2. Product Overview

Components:

Figure 2: Product exterior structure and labeled components.

1. Measuring Probes: Two sharp pins used to penetrate the material for moisture measurement.
2. Ambient Temperature Sensor Port: Detects ambient temperature for compensation.
3. LCD Display: Shows moisture content, wood type, and other indicators.
4. Switch Machine Key (Power Button): Turns the device on/off.
5. Max/Min Value Key (MODE Button): Toggles between Max, Min, and normal measurement modes.
6. Data Retention / Backlight Key (HOLD BL Button): Holds the current reading and activates/deactivates the backlight.
7. Wood Type Selection Key (Tree Icon Button): Cycles through the four wood categories.
8. Sensor Protection Cover: Protects the ambient temperature sensor.
9. Probe Protection Sleeve: Covers the measuring probes when not in use to prevent damage and injury.

3. Setup

3.1 Battery Installation and Replacement

The UT377A requires 3 x 1.5V AAA carbon zinc or AAA alkaline batteries (not included). To install or replace batteries:

1. Ensure the device is powered off.
2. Locate the battery compartment cover on the back of the device.
3. Slide or unclip the cover to open the compartment.
4. Insert three AAA batteries, ensuring correct polarity (+/-) as indicated inside the compartment.
5. Close the battery compartment cover securely.

Figure 3: Battery installation diagram.

3.2 Probe Protection

The device comes with a probe protection sleeve and a sensor protection cover. Always ensure the probe protection sleeve is in place when the meter is not in use to protect the probes from damage and to prevent accidental injury. Remove it before taking measurements.

Figure 4: Probe protection sleeve and sensor protection cover.

4. Operating Instructions

4.1 Power On/Off

• Press the Switch Machine Key () to turn the meter ON.
• Press and hold the Switch Machine Key to turn the meter OFF. The device also features an auto power-off function to save battery.

4.2 Wood Type Selection

The UT377A allows you to select from four wood categories to ensure accurate measurements based on material density. Refer to the 'Tree Species Correction Reference Table' (Figure 5) to determine the correct category for your material.

1. With the meter ON, press the Wood Type Selection Key (Tree icon ) repeatedly to cycle through the four wood categories (1, 2, 3, 4) displayed on the LCD.
2. Select the category that corresponds to the wood type you are measuring.

Figure 5: Tree Species Correction Reference Table.

4.3 Taking a Measurement

To measure the moisture content of a wooden material:

1. Remove the probe protection sleeve.
2. Select the appropriate wood category using the Wood Type Selection Key.
3. Firmly insert the measuring probes vertically into the material until the probe limit step (approximately 6.5mm deep) is reached.
4. Read the moisture content percentage (%) directly from the LCD display.
5. Press the Data Retention Key (HOLD BL) to freeze the reading on the display. Press again to release.
6. After measurement, remove the probes and replace the protection sleeve.

Figure 6: Key features and probe insertion depth for accurate measurement.

4.4 Max/Min Modes

To view the maximum or minimum moisture content recorded during a measurement session:

• Press the Max/Min Value Key (MODE) to cycle through normal, MAX, and MIN display modes.
• In MAX mode, the highest recorded moisture content will be displayed.
• In MIN mode, the lowest recorded moisture content will be displayed.
• Press the key again to return to normal measurement mode.

4.5 Backlight Function

To activate or deactivate the LCD backlight for better visibility in low-light conditions:

• Press and hold the Data Retention / Backlight Key (HOLD BL) for approximately 2 seconds.
• The backlight will turn on/off.

5. Maintenance

5.1 Probe Care

The measuring probes are made of SUS316 stainless steel for durability and a long service life (up to 5,000 vertical plug and pull cycles). To ensure continued accuracy and longevity:

• Always replace the probe protection sleeve when the meter is not in use.
• Avoid bending or damaging the probes.
• Clean the probes with a dry cloth after each use to remove any residue.

Figure 7: Durable SUS316 Stainless Steel Probes.

5.2 Cleaning

Wipe the meter's body with a soft, dry cloth. Do not use abrasive cleaners or solvents, as these may damage the casing or display.

5.3 Storage

Store the device in a cool, dry place, away from direct sunlight and extreme temperatures. If storing for an extended period, remove the batteries to prevent leakage.

6. Troubleshooting

• No Display / Faint Display: Check battery levels and replace if necessary. Ensure batteries are inserted with correct polarity.
• Inaccurate Readings:
  • Verify that the correct wood type category has been selected.
  • Ensure probes are fully and firmly inserted into the material.
  • Allow the meter to stabilize at the ambient temperature of the material being measured.
  • Clean probes if there is any residue affecting contact.
• Meter Does Not Power On: Check batteries. If new batteries do not resolve the issue, contact customer support.

7. Specifications

Figure 8: Detailed Specifications of the UT377A.

8. Warranty & Support

The UNI-T UT377A Digital Wood Moisture Meter is certified with CE and FCC, indicating compliance with relevant health, safety, and environmental protection standards. It has also passed RoHS testing, confirming its adherence to restrictions on hazardous substances.

Figure 9: CE Attestation, Calibration Certificate, and RoHS Test Report.

For warranty information, technical support, or service inquiries, please contact the seller or manufacturer directly. Keep your purchase receipt as proof of purchase.

9. User Tips

• Consistent Insertion: For best results, always insert the probes to the same depth and angle when measuring similar materials.
• Multiple Readings: Take several readings from different spots on the material to get a more accurate average moisture content.
• Acclimatization: Allow the meter to acclimatize to the ambient temperature of the material for a few minutes before taking readings, especially if moving between environments with significant temperature differences.
• Probe Protection: Always use the probe protection sleeve when the meter is not in active use to prevent damage to the probes and ensure safety.
• Battery Life: If the low battery indicator appears, replace the batteries promptly to maintain measurement accuracy.