Sonics VC750 (Serial No. "Y through "AB")" - Manual (Page 17)

14
IMPORTANT
Proper care of the probe is essential for dependable operation. The intense
cavitation will, after a long period of time, cause the tip to erode, and the power
output to decrease without showing up on the wattmeter. The smoother and
shinier the tip, the more power will be transmitted into the sample. Any erosion
of the probe tip will increase the rate of future erosion. For that reason it is
recommended that after every 5 or 6 hours of use the tip be examined, and if
necessary, polished with emery cloth or an abrasive wheel, or machined in a
lathe. Since the probe is tuned to vibrate at a specific frequency, it is most
important that only the contaminated surface be removed. This procedure can
be repeated as long as the power monitor reading is less than 20% with the
probe out of the sample, when the AMPLITUDE control is set at 100. If the
reading exceeds 20%, the probe or replaceable tip should be replaced with a
new one.