UNI-T UT343E Reference Check vs Adjustment vs Calibration Malaysia

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Published: 1 October 2026

A reference check, instrument adjustment and formal calibration are not the same process.

Understanding the difference helps users decide what to do when a UNI-T UT343E Coating Thickness Gauge produces readings that appear inaccurate, unstable or different from another instrument.

What Is a Reference Check?

A reference check confirms whether the UT343E responds reasonably when tested with its supplied reference plates and coating films.

A basic check involves:

Cleaning the probe.
Selecting the ferrous or non-ferrous reference plate.
Checking the uncoated plate.
Placing a known coating film on the plate.
Taking several readings.
Comparing the results with the film value.
Confirming that the readings are repeatable.

This check can be performed before routine inspection.

It does not produce a calibration certificate and does not establish traceability.

What Is Instrument Adjustment?

An adjustment changes the instrument response so that its reading corresponds more closely with a known reference.

Depending on the approved operating procedure, adjustment may involve:

Checking the uncoated substrate
Using a known coating film
Selecting the correct FE or NFE mode
Following the manufacturer’s adjustment steps
Confirming the reading after adjustment

Always follow the UT343E operating manual. Do not enter random correction values merely to make the reading match an expected production result.

What Is Calibration?

Calibration compares the UT343E readings with known reference standards under controlled conditions.

The process determines and records the difference between:

The reference value
The instrument reading
The stated measurement uncertainty
The acceptance requirement

Calibration does not necessarily mean that the instrument is adjusted or repaired.

A gauge can be calibrated and still show an error that must be considered during use.

What Is a Calibration Certificate?

A calibration certificate normally identifies:

Instrument model
Serial number
Reference standards used
Measurement points
Indicated values
Reference values
Measurement error
Measurement uncertainty
Calibration date
Calibration conditions
Traceability information where applicable

The certificate does not guarantee that every future measurement will be correct.

The user must still apply a suitable procedure and maintain the instrument properly.

Reference Check vs Calibration

Item	Reference Check	Calibration
Main purpose	Confirm basic response before use	Quantify measurement performance
Performed with	Reference plate and coating film	Controlled reference standards
Frequency	Before use or as required	According to the calibration programme
Certificate	No	Normally yes
Traceability	Not established by the check alone	May be provided according to the service scope
Detects obvious problems	Yes	Yes
Replaces correct measurement technique	No	No

Both processes are useful, but they serve different purposes.

When Should You Perform a Reference Check?

Perform a reference check:

Before an important inspection
After changing between FE and NFE substrates
When readings appear unusual
After transporting the instrument
After a long period without use
When the probe has contacted dirt or metal particles
Before accepting or rejecting a production batch
After the gauge has been dropped, if it remains safe to use

If the instrument repeatedly fails the check, stop using it for acceptance decisions.

When May Formal Calibration Be Required?

Calibration may be required when:

The company operates under a quality-management system
Customers request traceable measurement records
The gauge is used for final product acceptance
Inspection results affect safety or contractual decisions
The internal calibration interval has expired
The instrument was adjusted or repaired
Readings differ significantly from a verified reference
An audit requires current calibration documentation

The appropriate calibration interval depends on usage, risk, history and company procedures.

Why Calibration Interval Is Not the Same for Everyone

A coating thickness gauge used every day on a production line may require a different control programme from a gauge used occasionally in a workshop.

Consider:

Frequency of use
Working environment
Risk of impact or contamination
Required accuracy
Customer requirements
Previous calibration results
Instrument stability
Importance of the measurement decision

The company should define and review the interval instead of assuming that one schedule suits every application.

What If the Gauge Fails the Reference Check?

If the UT343E fails a check:

Clean the probe and reference plate.
Confirm the correct plate and coating film.
Check the FE or NFE mode.
Restart the instrument.
Ensure that the battery is sufficiently charged.
Repeat the measurement several times.
Test both supplied reference plates separately.
Record the displayed values.

If the readings remain unstable or substantially incorrect, arrange further inspection.

Do not keep adjusting the instrument repeatedly without identifying the cause.

Possible Causes of Incorrect Readings

Unexpected readings may result from:

Dirty probe
Contaminated reference plate
Damaged coating film
Incorrect substrate mode
Tilted probe position
Measuring too close to an edge
Curved or rough surface
Low battery
Damaged probe
Internal instrument fault
Unsuitable coating-and-substrate combination

Calibration cannot correct every problem. Physical damage or an unstable probe may require repair first.

Calibration vs Repair

Choose calibration when the gauge functions normally but its measurement performance must be evaluated and documented.

Choose inspection or repair when:

The probe is physically damaged
The instrument does not detect a metal substrate
The display or controls do not respond
Readings fluctuate severely on a clean reference plate
The gauge was exposed to water or chemicals
The instrument cannot be switched on or charged
An error remains after basic checks

A defective instrument should be repaired and checked before calibration.

Do Not Adjust the Gauge to Match the Product

Never change the instrument merely because the production result is outside the expected coating range.

First confirm:

Reference-check performance
Product specification
Substrate material
Measurement position
Coating condition
Sampling plan
Operator technique

The purpose of measurement is to evaluate the product—not to force the result into an acceptable range.

Maintain a Measurement-Control Record

Companies using the UT343E for quality decisions should retain records of:

Instrument model and serial number
Reference-check results
Calibration status
Repair history
Measurement procedure
Responsible operator
Inspection dates
Identified instrument problems

This helps determine whether previous inspection results may be affected when an instrument fault is discovered.

UT343E Support in Malaysia

Factories, automotive workshops and coating inspectors in Selangor, Kuala Lumpur, Johor and Penang should distinguish clearly between routine reference checking, instrument adjustment, calibration and repair.

For an initial assessment, WhatsApp MTM Precision a clear photo of the UT343E, its model label, reference plate, coating-film value and displayed reading.

MTM Precision Sdn Bhd
Showroom & Service Centre: No. 29-1 & 29-2, Jalan Bandar 18, Pusat Bandar Puchong, 47160 Puchong, Selangor, Malaysia
Tel: 03-8080 7172
WhatsApp: +6016-660 7346
Email: mtmpre@yahoo.com
Website: www.mtmpre.com.my

UNI-T UT343E Reference Check vs Adjustment vs Calibration Malaysia