a voltage ramp generator and a logarithmic amplifier. The TGCA is based on the AD8331 integrated circuit of Analog Devices which includes an ultralow noise preamplifier and a variable gain amplifier. The gain of the TGCA is controlled by the voltage ramp generator and increases with the elapsed time, thus compensating the
attenuation of the ultrasonic waves over the travelled distance. The logarithmic amplifier is based on the AD8310 integrated circuit of Analog Devices, an ultra-fast
responding and highly versatile logarithmic amplifier.Main receiver specifications are a bandwidth of 50 MHz and an adjustable gain in the range of 14–110 dB, which is enough to detect without problems most porous P/M parts that do not meet the quality requirements of the industry.