FAQ – Frequently Asked Questions

VVV-Group | Measuring Equipment

1. General Questions About the Company and Equipment

What does VVV-Group manufacture and supply?

The company specializes in professional measuring equipment, including:

Coating thickness gauges
Ultrasonic thickness gauges
Tint meters (glass light transmission meters)
Vibration meters
Diagnostic instruments for industrial and automotive applications

In which industries is the equipment used?

Automotive diagnostics
Industrial inspection
Non-destructive testing (NDT)
Energy sector
Service centers
Metal processing
Quality control and auditing

Does the equipment comply with international standards?

Most devices are designed in accordance with commonly recognized standards (ISO, ASTM, GOST — depending on the instrument type). Certification details should be verified for each specific model.

Is special training required?

Basic models are user-friendly and do not require formal technical education.
However, for industrial applications (especially ultrasonic testing and vibration analysis), operator training is recommended.

2. Coating Thickness Gauges (CM Series)

On which metals do the thickness gauges operate?

Ferromagnetic substrates (steel, iron)
Non-ferromagnetic substrates (aluminum, copper — FN models)

Is calibration required before use?

Yes. Zero calibration is mandatory before measurements to ensure accuracy.

Why do readings vary across different areas?

Possible reasons:

Coating thickness variation
Repaired sections
Filler material
Incorrect probe positioning
Measurements near edges

Can measurements be taken on dirty or wet surfaces?

No. The surface must be clean and dry.

How can repainting be detected?

Typical reference values:

Factory paint: usually 80–180 µm
Repainted surface: 200–400 µm
Filler material: 500+ µm

Exact values depend on the vehicle manufacturer.

3. Ultrasonic Thickness Gauges

What is the advantage of the ultrasonic method?

It allows thickness measurement from one side without damaging the material.

Can measurements be taken through paint?

Yes, if the device supports coating compensation mode. Basic models may require surface cleaning.

Why is couplant gel necessary?

The gel eliminates the air gap between the probe and the surface. Without it, measurement is not possible.

Why are readings unstable?

Possible causes:

Poor probe contact
Insufficient couplant
Rough surface
Incorrect sound velocity setting

Is it necessary to adjust the sound velocity?

Yes, if the material differs from standard steel. Incorrect velocity directly affects measurement accuracy.

4. Tint Meter (Light Transmission Meter)

What does VLT mean?

VLT (Visible Light Transmission) indicates the percentage of visible light passing through the glass.

Can factory-tinted glass be measured?

Yes. The device measures total light transmission, including factory tint.

Why do repeated measurements differ?

Possible reasons:

Misalignment of sensors
Dirty glass
Measurement in ceramic border area
Unstable positioning

Can laminated or double glass be measured?

Yes, but proper alignment of transmitter and receiver is required.

Does the device meet road inspection requirements?

This depends on the specific model and local regulations. Official inspections may require certified devices.

5. Vibration Meters

What parameter is better to measure — velocity or acceleration?

Velocity (mm/s RMS) — for general condition monitoring
Acceleration — for bearing condition evaluation

What values are considered critical?

For vibration velocity (general reference):

Below 2 mm/s — Good condition
2–4.5 mm/s — Acceptable
Above 7 mm/s — Requires diagnostics

Exact limits depend on equipment type and ISO standards.

Why measure in multiple directions?

Vibration has vector characteristics. Proper diagnostics require measurements:

Vertical
Horizontal
Axial

Can measurements be taken without a magnetic mount?

Yes, but measurement accuracy may decrease.

6. Accuracy and Calibration

What is the typical accuracy?

Depends on the model. Typical values:

Coating thickness gauges: ±(1–3%)
Ultrasonic thickness gauges: ±0.1 mm
Vibration meters: ±5%
Tint meters: ±2%

Refer to the specific model’s technical documentation.

Is annual verification required?

For commercial or official use, periodic verification may be required depending on local legislation.

Can calibration be performed independently?

Basic calibration — yes.
Official metrological verification must be performed by certified laboratories.

7. Operating Conditions

What is the operating temperature range?

Typically from +5°C to +40°C (refer to specific model specifications).

Can the equipment be used outdoors in winter?

It is possible, but measurement accuracy may decrease at low temperatures.

What should be done if an error appears on the display?

Restart the device
Check battery level
Perform recalibration
Check probe connection

8. Storage and Maintenance

How should the device be stored?

In a dry environment
Inside a protective case
With batteries removed during long-term storage

Do sensors require cleaning?

Yes. Especially:

Ultrasonic probes
Magnetic bases of vibration sensors
Optical windows of tint meters

Can the device be repaired independently?

Not recommended. Unauthorized repairs may void the warranty.

9. Warranty and Service

What is the warranty period?

Depends on the model and supplier. Typically 12 months.

What is not covered under warranty?

Mechanical damage
Water ingress
Improper use
Sensor damage

How can service be requested?

Contact the official supplier and provide:

Serial number
Description of the issue
Proof of purchase

10. Common Misconceptions

“More expensive means more accurate.”

Not necessarily. Proper calibration and correct methodology are more important.

“One measurement is enough.”

No. Reliable assessment requires multiple measurements.

“If the device turns on, it is ready.”

Not always. Most devices require calibration before use.

Conclusion

Measurement accuracy depends not only on the instrument but also on proper methodology.
Regular calibration, correct sensor positioning, and compliance with operating conditions are essential for reliable results.