Why Is My Moisture Meter Reading Always High or Unstable Malaysia
Why Is My Moisture Meter Reading Always High or Unstable Malaysia
Why does your moisture meter show a high reading?
Why does the number change when you measure the same wall or piece of wood again?
Does this mean the moisture meter is faulty?
Not necessarily.
Moisture readings can vary because of the material, measurement location, selected material category, probe contact, environmental conditions and measurement technique.
For users of a pin-type meter such as the TASI TA661B Digital Moisture Meter, understanding these factors can help produce more consistent and useful measurements.
1. Check the Material Setting First
The TASI TA661B supports multiple material categories.
Before taking a reading, make sure the selected category matches the supported material being tested.
This is especially important when moving between:
Timber
Plywood
Cement mortar
Gypsum board
Brick
Wall surfaces
Do not use one material setting for every surface simply because the meter displays a number.
2. Moisture Is Not Always Evenly Distributed
Real materials are not necessarily uniform.
A wooden board may have different moisture conditions at:
The end
The centre
The edge
Different sections
Similarly, a wall affected by water may produce different readings across a relatively small area.
Therefore:
Different Location = Potentially Different Reading
This does not automatically indicate an instrument problem.
3. Take Multiple Readings
Avoid making a decision based on one measurement.
For a wall, try:
Top → Middle → Bottom
or:
Left → Centre → Right
For timber:
End → Centre → Opposite End
Look at the overall pattern.
Multiple readings provide much more useful information than repeatedly testing one random point.
4. Keep Probe Contact Consistent
The TA661B is a pin-type moisture meter.
The probes need consistent contact with the material.
If one measurement has good contact and the next measurement has poor or different contact, the readings may not be directly comparable.
Try to keep:
Probe position consistent
Contact method consistent
Material setting consistent
Measurement procedure consistent
Repeatability starts with technique.
5. Surface Condition Can Affect Measurement
The area being tested may not be identical from point to point.
Possible differences include:
Paint
Coatings
Surface contamination
Repair material
Different layers
Different wall composition
Before concluding that the meter is unstable, consider whether the material itself has changed.
6. Are You Actually Measuring the Same Material?
A wall may look uniform while containing different materials underneath or across repaired sections.
For example:
Original Wall → Patched Area → Repaired Crack → New Plaster
Measurements across these areas may not behave identically.
This is particularly important in renovated properties.
7. Why Does the Reading Change on a Damp Wall?
A damp wall may contain a moisture gradient.
The centre of the affected area may differ from its edges.
For example:
Reference Area → Increasing Reading → Peak Area → Decreasing Reading
This pattern may actually be useful.
Instead of viewing the changing readings as a problem, use them to create a basic moisture map.
8. Why Is My Reading Always High?
First determine whether the reading is actually abnormal for the material and selected measurement mode.
Then check:
Correct material category
Probe contact
Measurement location
Surface condition
Comparison area
Recent water exposure
Environmental conditions
Do not assume that “high” automatically means “leaking pipe.”
9. A High Reading Does Not Automatically Mean Water Leakage
Possible reasons for unusual moisture conditions may include:
Plumbing leakage
Rainwater penetration
Waterproofing issues
Condensation
Recent construction work
Wet plaster
Previous water exposure
Material differences
The moisture meter identifies a material condition.
It does not automatically identify the cause.
10. Why Does the Reading Change Every Time?
Small variations between repeated measurements can occur because the probe position and material are not perfectly identical each time.
If the readings change significantly, check your technique.
Try this procedure:
1. Select the correct material mode
2. Choose one test location
3. Apply the probes consistently
4. Take the reading
5. Remove the meter
6. Repeat at the same or closely controlled point
Then compare the results.
11. Compare with a Reference Area
One of the most useful troubleshooting techniques is to measure a comparable area that appears unaffected.
For example:
Damp-Looking Wall → Normal Wall of Similar Material
or:
Problem Timber → Similar Timber from Same Batch
A reference area provides context.
12. Do Not Compare Different Materials Directly
Suppose you measure:
Timber = One Value
and
Brick = Another Value
The larger number does not automatically mean one material is universally “wetter.”
Different materials may use different measurement categories and behave differently.
Compare:
Timber vs Timber
Brick vs Brick
Gypsum vs Gypsum
whenever possible.
13. Check Whether the Material Is Still Drying
If you are monitoring a repaired wall, the reading may legitimately change over time.
For example:
Day 1 → Higher
Day 3 → Lower
Day 5 → Lower
This can provide useful trend information.
Use the same measurement points whenever possible.
14. Why Did the Reading Increase Again?
If a previously decreasing reading rises again, consider what changed.
Ask:
Did it rain?
Was the bathroom used?
Is there another water source?
Has the room ventilation changed?
Is the measurement point exactly the same?
Are you using the same material setting?
Investigate the pattern before drawing conclusions.
15. Temperature and RH Can Provide Additional Context
The TASI TA661B also provides ambient temperature and relative humidity measurements.
These can help document environmental conditions during testing.
However:
Material Moisture ≠ Relative Humidity
A high RH reading does not mean the wall or wood has the same moisture percentage.
Keep the measurements separate.
16. Do Not Search for One Universal “Normal” Number
A common mistake is asking:
“What percentage means everything is dry?”
There is no single universal moisture percentage suitable for every material and every application.
Acceptable conditions may depend on:
Material
Product specification
Construction requirement
Coating requirement
Manufacturing process
Customer specification
Use the relevant acceptance criteria for the application.
17. Use MAX and MIN Carefully
The TA661B provides MAX/MIN functions, which can help observe measurement variation.
However, these functions do not replace proper documentation.
For professional troubleshooting, also record:
Measurement location
Material
Selected mode
Date
Reading
Temperature
RH
Observation
This makes follow-up measurements more meaningful.
18. Use Data Hold in Difficult Positions
If the display is difficult to see while measuring, the Data Hold function can help retain the reading.
This can be useful around:
Lower walls
Door frames
Cabinets
Difficult-access locations
The function improves convenience but does not change the measurement technique itself.
19. When Should You Suspect an Instrument Problem?
If readings remain obviously inconsistent even after controlling the measurement conditions, further checking may be justified.
Before concluding that the meter is faulty:
Check Material Mode
↓
Check Probe Condition
↓
Repeat on a Stable Test Material
↓
Use Consistent Technique
↓
Compare Repeated Measurements
If the instrument still behaves unexpectedly, contact the supplier for technical assistance.
20. Check the Measurement Pins
Because the TA661B uses pins, inspect them periodically.
Check for:
Physical damage
Loose components
Contamination
Poor contact condition
The probes are part of the measurement system and should be kept in suitable condition.
A Better Moisture Measurement Procedure
For routine work, use the same procedure every time:
Identify Material
↓
Select Correct Mode
↓
Choose Measurement Points
↓
Apply Consistent Probe Contact
↓
Take Multiple Readings
↓
Compare Similar Materials
↓
Record Results
↓
Investigate Abnormal Patterns
This greatly improves the usefulness of moisture measurements.
TASI TA661B Troubleshooting Malaysia
The TASI TA661B Digital Moisture Meter can be used for moisture inspection involving wood and multiple supported building materials.
If readings appear high or unstable, do not immediately assume either:
“The meter is faulty”
or
“There must be a water leak.”
First check the material setting, measurement technique, probe contact, measurement location and comparison method.
Good measurement technique is just as important as choosing the right instrument.
For technical assistance, quotation or product availability for the TASI TA661B Digital Moisture Meter in Malaysia, contact:
MTM Precision Sdn Bhd
Showroom & Service Centre
No 29-1 & 2, Jalan Bandar 18,
Pusat Bandar Puchong,
47160 Puchong, Selangor.
Tel: 03-8080 7172
WhatsApp: +6016-660 7346
Email: mtmpre@yahoo.com
Website: www.mtmpre.com.my
26 Sep 2026
