
D. LOW LEVEL LEAKS
In ultrasonic inspection of leakage, the amplitude of the sound often depends upon the amount of turbulence generated at the leak site. The greater the turbulence, the louder the signal, the less the turbulence, the lower the intensity of the signal. When a leak rate is so low that it produces little, if any turbulence that is "detectable", it is considered "below threshold". If a leak appears to be of this nature:
1.Build up the pressure (if possible) to create greater turbulence.
2.Utilize LIQUID LEAK AMPLIFIER.
This patented method incorporates a UE Systems product called LIQUID LEAK AMPLIFIER, or LLA for short. LLA is a uniquely formulated liquid substance that has special chemical properties. Used as an ultra- sonic "bubble test, a small amount of LLA is poured over a suspected leak site. It produces a thin film through which the escaping gas will pass. When it comes in contact with a low flow of gas, it quickly forms a
large number of small
NOTE: The low surface tension of the LLA is the reason small bubbles form. This can be negatively changed by contamination of the leak site with another leak fluid which can block LLA or cause large bubbles to form. If contaminated, clean the leak site with water, solvent or alcohol (check with plant regulations before selecting a decontaminating cleaning agent).
LLA
E. TONE TEST (Ultratone )
The Tone Test is an ultrasonic method for
CONTAINERS, TUBES, PIPES, HEAT EXCHANGERS, WELDS , GASKETS, SEALS, DOORS, WINDOWS, OR HATCHES.
The test is conducted by placing an ultrasonic transmitter, called TONE GENERATOR, inside (or on one side) of the test item. The warble