Advances in microprocessor technology by some extremely clever people has led to today's sophisticated instruments.

A transducer containing a piezoelectric element is placed on the radiator steel. The element excited by a short electrical impulse generates a burst of ultrasonic waves.

These waves travel through the steel to reflect off the far side and back to the transducer, which converts the sound energy back into electrical energy.

The time interval for the sound waves  to make the round trip is only a few millionths of a second. From this the instrument calculates the thickness of the steel.

In "echo to echo" mode waves pass through the paint, hit the surface of the steel and return a first echo. Then  waves return a second echo from the far side of the steel. This enables the instrument to calculate the steel thickness alone without removing the manufacturers original paint.

If the radiator is over-painted  then for accuracy  testing may be done at the rear on the original finish.

The original steel thickness was min 1.2mm
Several tests show that it is now 1.1mm This shows that a loss  of  less than 10% produced enough sludge to cause cold areas on the radiators.

It takes very little corrosion within a radiator to produces an alarming amount of oxide sludge.The system was cleansed.

The Microgage 11 is so accurate that we could easily see where steel was stretched and slightly thinner around pressed areas.

Radiator manufacturers were amazed at its accuracy.

For accuracy comparisons are only made with each individual manufacturers supplied steel sample. Their assistance is much appreciated.