For the standard 25mm delay line, the nearfield is contained within the delay line close to the coupling face. The beam spread in the asset will be dependent on the material being inspected. 

The standard format is a 25mm long, 30mm wide delay line, 10mm diameter spot contact with a 3MHz transducer. These parameters have been optimised to for thickness measurement in steels up to 23mm in depth at temperatures up to 380°C.

Different delay lengths are available on special request, but consideration of the transducer nearfield and total transducer length and Ex requirements should be taken prior to ordering.

Ionix are available to offer advice and guidance when selecting the delay line for your application.

Different diameters and frequencies are not currently available, but please register your interest with Ionix Advanced Technologies from the contact page.

HotSense™ transducers are compatible with all flaw detectors, UT thickness gauges, and proprietary hardware that we have tested to date. Ionix do not recommend the use of thickness gauges without A-Scan capability, and should only be used once measurements on calibration pieces have been made to validate readings.

Ensure that the pulser max/minimum voltages are compatible with the HotSense™ transducer specification.

Ideally the transducer should be pulsed at 3MHz with a 100 – 170ns wide pulse, although hardware with 2MHz, 2.25MHz or 5MHz settings can also be used.

Adapters are available for connectivity of the transducer to your hardware. Contact Ionix Advanced Technologies for further information.

Ionix does not recommend a high temperature dispensable coupling liquid, gel or paste that is suitable for continuous use at high temperature. Available high temperature coupling gels may be used for positioning of the sensor during installation, but transducer face and asset surface should be thoroughly cleaned with a non-flammable solution prior to coupling with a foil.

• Ensure the pulser-receiver is set to operate in pulse-echo mode
• On multi-channel instruments ensure that the correct channel is selected
• Turn the gain up on the pulser-receiver or flaw detector
• Ensure pulser output is enabled and pulser voltage is adequate.
• Set the A-Scan delay to 0 and the range to 100mm in steel (approx. 40us)
• Inspect the cable and connections for damage
• Connect a spare HotSense™ Transducer to the instrument, without coupling. Check that the instrument can be set to receive an A-scan with a delay line reflection present

• Is the A-scan window/range wide enough? Ensure adequate time is given to receive the backwall signal.
• Is the backwall reflection overlapping with the delay line repeat echo? This will occur if the time of flight through the asset being inspected is the same as the time of flight through the delay line.
• Ensure that the delay line length is greater than the asset wall thickness.
• Do you observe a reflection from the delay line? If so then it may be that coupling between the transducer and asset has not been successful.
• In circumstances of extreme pitting or where the back wall is angled, a usable signal may not be returned, try coupling the transducer in a different location.
• If an extension cable or adaptor is fitted, remove this and check connections. Replace if necessary.
   

• Ensure the filters on your pulser receiver are off, or configured for a 3MHz signal. If 3MHz is not available then either 2MHz, 2.25MHz or 5MHz should be used depending on which provides the optimum signal for your application.
• Ensure the pulser receiver gain has been turned up.
• Ensure that the pulser output is enabled and the pulse voltage is adequate.
• Is the reflector non-parallel? This would result in minimal signal being reflected to the transducer and low amplitude backwall reflection.
• If the delay line reflection is significantly higher amplitude than backwall reflection, then coupling may not have been optimised.
• Has the foil couplant been correctly inserted and has the transducer been tightened adequately to deform the foil and achieve coupling.
• If coupling is not being achieved using a foil couplant then attempt coupling using a gel couplant that is rated to the asset surface temperature.