FAQs about Ultrasonic Thickness Gauge

Can I measure through more than 5/16?

There is a special feature called ‘Deep Coat’ that can allow Cygnus gages to measure metal thickness through up to 3/4″ (20 mm) of coating. Please contact Cygnus for details of how this feature can be enabled on certain gages. Please note however the ability to measure through thick coatings depends entirely on the type of coating, we can not guarantee the gage will measure through every type of coating.

Can I use non-Cygnus probes on my Cygnus gage?

Only Cygnus probes should be used with Cygnus gages. The specifications of Cygnus probes is carefully controlled to ensure optimum performance from your Cygnus gage. Using non-Cygnus probes may cause incorrect or unsatisfactory operation.

Can the gages be used on materials other than steel?

Yes. Although the majority of applications require the gages to be used on steel, the gages can be used on a variety of other materials by either entering the known velocity of sound into the gage in metres per second, or by calibrating the gage with a known thickness of the material under test. Typical examples include, aluminium, copper, grey cast iron, magnesium, nickel, mild steel, tool steel, stainless steel, tungsten, monel, inconel, phosphor bronze and brass.

Do I need to change the sound velocity on the gage when measuring different materials?

Yes, otherwise an incorrect reading will be shown. For the Velocity Table click here. These are also listed in the manual supplied with the gage.

If only a few measurements are to be taken on a material other than Steel, it may be easier to leave the calibration set for Steel and convert the readings by multiplying by the Conversion Factor for the material being measured:

True Reading = Reading x Conversion Factor

Conversion factors are listed in the Velocity Table. This method avoids unnecessary re-calibration.

Does the gage need to be calibrated? If so, how often?

All Cygnus gages are calibrated for Steel when they are manufactured and the calibration can be adjusted to suit the type of material under test. Certificates of calibration are issued at the factory. The gages can be returned for recalibration at the customer’s request and in accordance with their own quality requirements. This is usually every 12 months when the equipment can be tested, checked and recalibrated using equipment traceable to national standards.”

The European Standard BS EN 15317 ‘Characterization and verification of ultrasonic thickness measuring equipment’ recommends all gages to be subject to an annual Performance Check to ensure correct operation. All new Cygnus gages are manufactured in accordance with this standard.

How does Multiple Echo ultrasonic thickness gaging work?

For this information please see our Technology page.

I am having difficulty getting thickness readings?

Assuming the batteries are good the next thing to check is if the Probe Membrane is fitted correctly, has enough couplant behind it and is not damaged or worn. There are instruction on Probe Membrane care on the Technical Downloads page.

A correctly fitted membrane is essential for optimum gage operation

Gain Settings. Some Cygnus gages have a Gain Setting in their menu:

  1. If the Gain in too low then getting readings will be difficult or impossible.
  2. If the Gain is too high then the gage may display standing readings when the probe is not in contact with the material surface.

To correctly set the Gain follow these simple steps:

  1. Make sure the probe face is clear of couplant and is not touching any surface.
  2. Set the gain to a high value (i.e. 12).
  3. Observe the thickness display – If you see more than one flashing bar or a thickness value then reduce the gain by 1 and check the display again. Continue to reduce the gain untill you see one flashing bar on the display.
  4. You now should have reduced the gain so the gage is consistently displaying one flashing bar only.
  5. The Gain has now been correctly set.
Is Cygnus Data Logging software (CygLink) compatible with Windows 7?

Yes, the Cyglink application will work with all versions of Windows (2000, XP, Vista, 7, both 32 & 64 Bit versions).

However, the serial to USB converter may require the latest driver installing. You can download the latest drivers for the USB to Serial Converters from Technical Downloads

The small grey USB to Serial Port Cable

The small grey USB to Serial Port Cable

The Black USB-485 Converter from KK Systems

The Black USB-485 Converter from KK Systems

What certification does Cygnus Instruments have?

The company has BS EN ISO 9001:2000 certification for the design, development, manufacture and repair of ultrasonic measuring equipment and associated accessories.

What is the warranty period for Cygnus gages?

3 years for the instrument and ancillaries.
6 months for the probe.

What make of batteries do you reccommend?

Cygnus recommends Duracell Procell batteries for all gages that require disposable batteries.

What product training do I need?

Click here to find out how ultrasonic measurement works.


If you still can’t find the answer to your question, please click here to send us your enquiry or call us on +1 410-267-9771 directly. We are more than happy to help you.