14 May
2014
14 May
'14
1:04 p.m.
They might not be but their big brothers the SONAR T/R
units use=A0piezoele=
ctric crystals in contact with water.=0A=
I guess this can be repeated here...
An old trick for waterproofing nroaml transducers (audio and ultrasonic,
including microphoes) is to put a thin rubber membrane over the business
end. Such membranes are sold (for a rather different purpose) in most
pharmacies....
The story goes that the new guy in a research group was sent down to the
local pharmacy to buy a large number of boxes of condoms. Said guy then
asked for a receipt 'so I can claim on expenzss'. 'You can claim _those_
on expenses ?!? Where ever do you work?'
-tony