TWI Frequently asked questions
by Ivan Pinson
It is the duty of the ultrasonic operator to check the performance of his equipment regularly. Details are given in EN 12668-3 (see below). This specifies the following checks with the recommended frequencies given.
a) Linearity of the flaw detector's time base - weekly b) Calibration of the time base - whenever a probe is changed
c) Linearity of equipment gain - weekly
d) Index points on all angle probes - at least daily
e) Angles of all probes - at least daily
f) Sensitivity and signal to noise ratio - daily
g) Beam alignment (squint) - weekly or when damage is suspected
h) Beam width in vertical plane - daily
i) Pulse duration - daily
EN 12668-3: 2000 Non-destructive testing - characterisation and verification of ultrasonic examinations equipment - Part 3 : Combined equipment.
