Notes on Ultrasonic Method of Measuring Thickness of Ice Cover

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Publisher’s version / Version de l'éditeur:

Technical Note (National Research Council of Canada. Division of Building Research), 1954-02-04

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https://doi.org/10.4224/20338459

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Northwood, T. D.

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DIVISION OF BUILDING RESEARCH

NATIONAL RESEARCH COUNCIL OF CANADA

'fEClHIN II CAlL

No.

174 NOTlE

NOT FOR PUBLICATION FOR INTERNAL USE

PREPARED BY T.D. orth 00 CHECKED BY APPROVED BY ｾ

PREPARED FOR _{• Gunnar Nybl"ant,}

Stockholm. ｄａｾｅ

4

Febru ry

1954

ethod of suring

,

onth 1 d v lop ent it w decide th t it would

a ati t _{ctory d vic}

ot

_thi _typ. _{Conaequ ntly}

in favour of much 1 1" m thod hich i

After t 0 or thre

be impossibl t d v lop

th project wa opped,

､･ｳ｣ｲｬ｢･ｾ elsewhere •

In conn etlon with Ex rei kox, in

1946,

th Acoustic

LboI' tory w s ask to con ider th d velopment of an cou tic

for the measurement of thlckn of ice cover on lak and 1"1vel" , to

etermin ita bearing tr ngth. Th proposal w to use an ultrasonic

echo-ranging yst mz 1. ., to transmit an ultr onic pulse through the

ice and measur the ti e whioh 1 p for an cho 1:1"0 th bot tom

of the ice was 1" ceiv •

Unfortunat ly, no formal report was produc d on th ultra onic

method. The following note ar off- _{nd r collections, m inly of th}

Ifticulties which made the m tho mpr ctieal.

Operational Requirement I

Tentative sp eifioation W 1" fol10ws:-

,

(1) Th evioe u t either be compl t ly port bIoI' 1 e have

portabl probing unit conn cted by a light cable to the, main

unit, or to a power upply mount 1n a v hicle.

(2) t w s de 1rable th t i t contlnuou -I' a . ng yst • Failing

that, a very fast, mple m Burin operation would b requir d,

80 th t i t woul be practicabl to t t very 10 tt., say, in

cr1 tical I' gions.

(3) The davie sho 1 measur th!c

1 st

4

ft. (th latter tbiokne

avy aircraft) •

Bea fro tew inche to at

being i portant tor landing

.. "Dr!ll for Det rmining Thielen s of Ice"

by T.D. orthwood: Can.Jour.Re e ch,

F,25:

. 196-191, l<1arch 1941. (NRC No.1514).

(3)

2

to th con lu ion that th

unit, caxeri d ahe d of hicl

cathod -ray tub indicator was

to opel' t tram tor g

not eon 1d r d

t

_aaibl, _ut

pplled to the ic with 11ttl or

14eratlona

Varlou pr ctieal r quir t 1

vic ould consi t

ot

_a ₁₁ _rob

which could cQrry the control unit.

plann d, d th 01 un1t 19n

battery. ｣ｯｮｴｬｮｵｾｵ p ading d 10

it whop d th t th prob could b

no PI' .paratlon of th e urtac.

_,

).

Tn n c ssity

ot

_me _urlng _+c _a _thins

4

_to ₆ _inches

eriou .limit tion, inc 1t requ1tt d th U

ot

very ahort

high-r qu ncy pul e· ( pproxi at 11' 300 Kilocrel a,

3

or

4

01c1 long).

Observation

Th t1r t ｾ st

ot

_br

ott

w

R1v r, 11 1n th winter, wh n

r suIts weI'

very pram! log

at th1

pl

t prototyp. on lIhlch th e 1'11 te t snow. • Co nta

(1) It

i tor t 1e l' n ad to work. a1.

untortunat 1"1 the

thin-. l

(2) S veral v 1 tiona of th t h " in puticul .' a resonanc method,

W 1'8 considered.. The lat er g va r _.\Iult . which were comparable to

but not 19n1:flcantly batt r than th origin 1 seh e.