Coating Thickness Gauge vs Ultrasonic Thickness Gauge What Is the Difference Malaysia
Coating Thickness Gauge vs Ultrasonic Thickness Gauge – What Is the Difference Malaysia
Content
Do you need to measure the paint on top of a steel plate, or the actual thickness of the steel plate itself?
These are two different measurements and normally require different instruments.
A coating thickness gauge, such as the UNI-T UT343A, is designed for measuring suitable coatings over compatible metal substrates.
An ultrasonic thickness gauge is typically used to measure the thickness of the material itself, such as the remaining wall thickness of steel.
Understanding this difference can prevent purchasing the wrong instrument.
Simple Difference
The easiest way to understand the difference is:
Coating Thickness Gauge = Measures the layer ON the metal
Ultrasonic Thickness Gauge = Measures the material thickness itself
For example, imagine a painted steel plate.
The paint may be:
120 μm
while the steel plate itself may be:
6 mm
These are completely different measurements.
What Does UNI-T UT343A Measure?
The UNI-T UT343A Coating Thickness Gauge is intended for compatible coating measurements on Fe and NFe metal substrates.
Typical applications include:
Paint on steel
Powder coating on metal
Coating on aluminium
Automotive paint inspection
Fabricated metal coating inspection
Manufacturing QA/QC
Its measuring range extends up to 1750 μm.
The instrument is therefore useful when the question is:
''How thick is the coating?''
What Does an Ultrasonic Thickness Gauge Measure?
An ultrasonic thickness gauge is commonly used when the question is:
''How thick is the actual material?''
Typical applications include:
Steel plate thickness
Pipe wall thickness
Tank wall inspection
Pressure vessel inspection
Corrosion monitoring
Remaining wall thickness
Maintenance inspection
Measurements are commonly expressed in millimetres, depending on the application and instrument.
Example 1: Painted Steel Plate
A factory has a painted steel plate.
They want to check whether the paint coating is being applied consistently.
Correct instrument category:
Coating Thickness Gauge
A model such as the UNI-T UT343A may be suitable depending on the coating and substrate.
If the customer instead wants to know whether the steel plate is:
4 mm, 5 mm or 6 mm thick
then an ultrasonic thickness gauge would normally be the relevant instrument category.
Example 2: Corroded Pipe
A maintenance department needs to check an old steel pipe.
The concern is that corrosion may have reduced the pipe wall from its original thickness.
The question is not:
''How thick is the paint?''
The question is:
''How much steel wall remains?''
This is an ultrasonic thickness measurement application.
Example 3: Powder-Coated Cabinet
A manufacturer produces powder-coated metal cabinets.
QA/QC needs to check whether the powder coating is consistent across the:
Door
Side panels
Top panel
Rear panel
This is a coating thickness measurement application.
A suitable Fe/NFe coating thickness gauge can be used to take several readings and compare the results.
μm vs mm – Another Useful Clue
Coating thickness measurements are frequently discussed in micrometres (μm).
Material and wall thickness measurements are commonly discussed in millimetres (mm).
Remember:
1 mm = 1000 μm
Therefore:
100 μm = 0.10 mm
A paint layer of 100 μm and a steel plate of 5 mm are on very different thickness scales.
Can UT343A Measure Steel Plate Thickness?
Do not use the UNI-T UT343A as a substitute for an ultrasonic thickness gauge when the requirement is to determine the actual steel plate or pipe wall thickness.
UT343A is a coating thickness gauge.
If your application is:
Steel plate thickness → consider ultrasonic thickness measurement
If your application is:
Paint thickness on steel → consider coating thickness measurement
Choosing by application is more important than choosing by instrument name alone.
Can an Ultrasonic Thickness Gauge Measure Paint?
This depends on the instrument, probe and measurement method.
Some ultrasonic systems have functions designed to deal with coated materials, but this should not be confused with using a dedicated coating thickness gauge for routine paint or powder coating inspection.
Always identify exactly which layer needs to be measured.
Four Questions Before Buying
Before requesting a thickness gauge, answer these four questions:
1. What material are you measuring?
Steel? Aluminium? Pipe? Plastic? Another material?
2. What thickness do you need?
The coating or the actual material?
3. What approximate range do you expect?
For example:
120 μm coating
or
6 mm steel wall.
4. What is the application?
Paint inspection? Powder coating QA? Corrosion inspection? Pipe maintenance?
These details quickly narrow down the correct instrument category.
UNI-T UT343A for Coating Inspection
For users who need coating thickness measurement, the UNI-T UT343A offers:
0–1750 μm measuring range
Fe/NFe substrate support
Automatic substrate recognition
Single measurement
Continuous measurement
MAX/MIN/AVG
199 data storage
μm/mil units
Upper and lower limit settings
It is suitable for many applications involving paint and coatings over compatible metal substrates.
Thickness Gauge Selection Malaysia
MTM Precision supplies measuring and testing instruments for industrial, maintenance, automotive and QA/QC applications in Malaysia.
If you are unsure whether you need a coating thickness gauge or ultrasonic thickness gauge, send us:
Material + What layer you want to measure + Expected thickness + Application
For example:
''Paint on steel, around 100 μm, powder coating QA.''
or
''Steel pipe wall, approximately 6 mm, corrosion inspection.''
This allows us to recommend the correct measurement method instead of simply selling a ''thickness meter''.
MTM Precision Sdn Bhd
Showroom & Service Centre: Puchong, Selangor, Malaysia
Tel: 03-8080 7172
WhatsApp: +6016-660 7346
Email: mtmpre@yahoo.com
Website: www.mtmpre.com.my
22 Sep 2026
