Pulser Frequency Selection (Pulse Width); Receiver Adjustments; Digital Receiver Filters - Olympus EPOCH 650 User Manual

5.4.6

Pulser Frequency Selection (Pulse Width)

The pulser frequency selection sets the pulse width when Pulser > Pulser = Square.
This frequency selection allows you to tune the shape and duration of each pulse to
obtain the best performance from the transducer being used. In general, the best
performance is achieved by tuning the pulser frequency as close as possible to the
center frequency of the transducer being used.
To adjust the pulser frequency
 Choose Pulser > Freq, and then vary the setting.
Actual results could vary due to the test material and/or variation in the transducer
center frequency. Try various settings with a transducer and test piece to maximize
ultrasonic performance.
5.5

Receiver Adjustments

The receiver settings are accessed from the Rcvr menu. The receiver parameters are:
•

Digital Receiver Filters

• Waveform Rectification
5.5.1 Digital Receiver Filters
The has a total instrument bandwidth of 0.2–26.5 MHz at −3 dB. The instrument offers
30 standard fixed digital filters. These are designed to improve the instrument's
signal-to-noise ratio by filtering out unwanted high and/or low frequency noise
outside of the test frequency spectrum. The Standard filter set also allows the
instrument to provide the dynamic range (dB) required by EN12668-1:2010.
In most cases, you should select either a broadband filter or a narrow-band filter that
covers the frequency of the transducer being used. Due to the shifting of frequency
spectrum in most materials, it might be necessary to adjust the filter settings to
maximize instrument performance. Every material is different, and you must
optimize the receiver settings based on the application.
DMTA-10055-01EN, Rev. A, February 2015
Adjusting the Pulser/Receiver 111