Using new technique of multiple echo(echoto-echo), SA40+ can measure wall thickness under paint. For a normal ultrasonic thickness gauge, you must remove paint on work piece, but with new SA40+, you can take measurement directly over the paint of work piece and you can get real thickness value of work piece.
SA40+ has two measuring modes: normal mode and multiple echo(ME) mode. By normal mode, SA40+ is a normal ultrasonic thickness gauge; by ME mode, SA40+ can measure over coatings.