CA2009647A1 - Article counting systems - Google Patents

Abstract

ABSTRACT
There is described an article counting system in the form of an apparatus and a method of utilising the apparatus which counts accurately a number of discrete articles decanted from one container into another. The system is based on the articles impacting a sensor to produce a proportionate electrical signal. The apparatus includes detector means to detect said proportionate electrical signal and produce a second signal when the magnitude of said proportionate electrical signal lies within a predetermined magnitude range. The system has the capability of differentiating between the impact caused by more than one article impacting the sensor simultaneously. The system has particular application in the counting of fish.

Description

Z01~9647 1 "Article C.~un~ 5Yste~

~ hl~; invelltion r.el~s ~u ~rticle counting system~, and si ~lore partit~l ULly l~ut not exclusiv~ly to thc counting ~L ~J. t icles wtll oll Llre movialg ,t n a s~re;~m or c~c~da.

7 lf a l,~r~e nllmb~I ~f ~imil~l- discrete articles a~e decante,1 fl-c)m a c~l-ltaincl- over~ a period Or time, i.t may ~ ~e ~ifii~L ~. impos~ le to ensure thAt the ~ticle~
c~re clec.~nte~ ~..inyly. Thu3, a conventional o~ounting ll system sen.~;t~r. d~ stro~m of the ~ontairler ~nd whi~h l~ switches st~t~ in ~epelldcllcc on the pre~ence or Absc~cc 13 uf ~n ar.~icl~ t~ cause n mis-count by l4 ~spon~i.3l9 only vnce if two Qr more articles pa~s 1.~ togeth~r or in very ol~s~ succcsslon. Such a lfi conventional sl~nsor is ~lso liabl~ t(? çaur~l~ a mis-count .l7 ~y r~3~ g at l~tl~t ~wic~ if A sint31e Irti.cle l8 bounce~ orl ~he 3~n50r.

2U l~ i..s ~tlet-t-Lore ~n ~b~t o~ the invention to pr~vide ~1 ~n cl~ticl~ c~untin~ sy~tem ~ornpri3in~ ~pp~r~tu~, and a 2~ mctl~o~-l of: utilisin~ 'h~ ~pparatus, wnich obviates or 23 ll~iti~.~tc:s th~: abovr--~le~;Crib~d disadvantAgc of ce,rlverltiorl~l .~ountin.~3 3y~t~m~;.

. , ', ' ,. ~ : : . -~ ' . ' 1 According tu a f lrst as~t of the pr~s~nt inv~ntionther~ i ~ provi~e~d article aour~till~ apparatus h~ving a 3 sensor s i gnal 1nput cvrlnected in U5C to a sen~:or whic~h transduces i.mp~ct to ~ proportiona~e electric~l signal, 5 sai~l ~ppar~tus further including deteator mean~
6 connecte~ to sak1 input to detect 3~id proportionate eleçt.ri ~ ignal in u~,e and to produce a ~harac~ristic output signal whell th~ magnitude of said prop~rtionatc electr.iCal ~i~nal lio~ within ~r~d~termined m~gnitud~ r~n~e, 1.2 Sai~ app~ra~uc, pr~ferably i~lcludes a countcr actuator 13 oircuit coupl~ to receive ~he ou~pu~ nals of the 14 detector means, said counter actuator circuit fuJlctioning in use to prv~luc~ successively i.ncrement$ng .l~ counter acLu~tions ~l~ell an output signal is roceived.
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18 .~;aid ~l~t~ctor means may ~e a level ~eteGtor ~ircuit 1~ such ~ to pro~3uGe a respecti~ ~haracteristic o~tput si~nal when ~he ma~ ude oE saic~ proportionate ~1 ~lectrioal signal lies ~ithi-l on~ o~ a plurality of ~2 predetermil~ed r~n~es of magniLu~e~, said respec~ive 2~ charac~eristi~; output si~ ls l~cing mutually distinat Z ~ y t~ d c l~ ~ i f ~ h ~ ~ o ~ pc~ t i ~r o r~ o ~
plurali~y of ran~es ar~ preferably contiguou~ ~nd 2~ in~reasé ln magni~u~ fro~n a minimum ~hre~hold 2~ magnltud~ ~hic~l Lh~ old may be ~ero or non-~cro) up 28 to a ye~k ma~llituc~e (which pe~k may bc determinate or ~9 incleterminate). lJrefer~ly als~, the counte~ aGtuator ~U circuit COuple~l Lu t-~ceive the output 9ignal3 of thc :1 l detector means in u..e produccs s~cce3~ively 32 incrementin~ coun~er actuati~rl~ as the pr~portionate 33 electrical sl~nal trav~rs~ ~anyes of successive 34 increasin~ magnltudes, su~l~ Lh~ tlle incrementati~n of ~5 counter actuations serve~ to iden~ify respective ranges :, .: :

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3 20~9647 1 Or increasin~ magnit~de~.

3 Said apparatus preferably in~ludes means ~or conjointly 4 ~r independently va~ying the lower and uppe~ limit~- o~
the ~r each sai~1 range of m~ itude to allow ~elective ~ ~ariati~n of t~le ~recl~termination of thc ran~e or 7 ran~es or m~nitu~e. 1~here~y the counting sy3tem can ~ be a~justed to dis~rimin~te between the impact of 9 ~ingle article an~ the r~pecti~e simultaneous impact~
of two artiG~es three ~rticles etc.

l~ A~cor~ing to ~ secotld asp~oL or the invention there i~
13 provi~d an article c:curltil-y ~stem co~prising a S~nEor 14 functioning in use to trans~lu~ impact to a L5 proportionate electri~l si~nal and article counting l6 apparatu~ according ~ Lhe first a~pect of the 11 invention navln~ its ~n~or signal input coupled to l~ receive 6aid signals fr~m said sensor ~nd including a l9 counter actuator circuit a~ afores~id ~said system 2~ further includiny ~n increm~rlting counter coupled to 2I said count~r actuator clr~uiL to be actuate~ thereby 2Z sal~ sensor ~;JI~ arranged to produce tr~nsicnt 23 response ~o tt~e pa~s~ vr an article whereby 3~id 24 counter is incremente~ upon eaGll ~u ~ a~a~e. 'I'he sensor is prefera~ly either arranged to ~ ~irectly 26 impact~d by a cascade or stream o the articles or 27 alternatjvely the sensor is ~ou~1~ or cvnnecte~ to a 28 sur~ac~ wll~ich i6 ~irectly im~ct~d by a ca6cade or 29 ~tream Or tl1e artic1e~. The sen~.or may ~e mechanically acoustically opti~lly ~r- otll~rwise 31 coupled tO the surface w~lk~ dy be rigidly or 3Z non-rlq1clly moun~. In ~]1 c~ses the imp~at of one 33 or more articl~s resul~ a proportion~e electric~l 3~ siqnal. If ttl~ ~L ~icl~s are identlcal or no~
3Fj eXCessively dissimilllL ill mass~ the irnpact of a sing1o .~-.

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20(:~6~7 1 article wll l pr~cluce a si~llal lying within a certain 2 ~elatively narrow range vf m~ynLtudes. e~onvers~ly, the 1 si~ultaneous impact of two ~rti~les ~ill produce ~
4 si~nal lying within ~I range of m~gnitudcs which is significantly hi~her than the range of ~gnitudcs for 6 the impa~ of a ~ingle ~rti~le. 5imilarly, t.h~
7 si~ultaneous impact o~ thr~ articles produces a ~ignal whose ma~nitu~e is hi~ r ~gain than thc ~ignal for two 9 Art icles . on t~e ot~er hand~ iL ~n article bounces and ln re-impact~ on the sen~r or the surf~ce to ~hich the 11 sensor is connected, the r~sult will bc a ~i~nal who6e 12 m~gnitude is si~nifi~alltly low~r than the magnitude o~
13 the signal producet~ by the f irst impact of a sin~le 1~ article.
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1~ Thus, the detector m~ns pre~ecably operat~s to respond 17 only ~o sensor signa1s a~ove a ~L~hold ~elow whi~h 18 ~he low ma~nl~ude ~ ~ensol- signal c~n r~sonably bo 1~ ascribed to ~ounce~ rath~r ~hnn A direct imp~ct. Above 20 tni s ~hresnold t~ et~ctor meAns i3 prefcra~ly Zl arranqed to discrimina~e ~etween signals repre~entin~
22 the simult~neou~ impact ~ one, two, thrce (and 23 possihly more) art1cles wi-)l tl-l~ counter actuntion 24 circuit respec~ively causing ~lle oount~r to increment by one, two, three, et~. Th~el~y the counti.ng ~yctcm 26 is relatively immune to mi~-uuunts cnused by bouncing ~/ and by simul~nlleous multiple imp;~cts.

2Y Acco~ing ~ d third aspec,t uf thc invention, there i~
provic~ed ~ mcthod Or UuUIIti.1lg articles, ~aid ~cthod ~1 utilising ~l~e artlcle counting syste~ of the second ~ aspect o~ the invention, ~ui~ method compri~ing the 33 steps o~ ~ecanting or di~harying the article~ from a 34 container or a ~ranspor~ d~vice to drop or otherwisc i~pac~ Upon th~ SOl- or the s~rface to ~hic~ the ' :
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Z0C~3647 1 sensor i ~ coupled or co~ ccted, the r~te ~f de~nting or dis~ ar~ lq being ~assivcly or actively controlled 3 to li~it th~ ~hor~-term fre~uenoy of impa~ to a 4 relatively ~m~all value (plererably such that imp~ct~
~ are u~ually o~ ~in~le artic,les, and r~rely, if ever, of f~ more tha~ two ~r ~hree ~rticles simultaneously), a~
7 operatin~ the apparatuS to ~ount the num~er of impact~
~ Such tha~ the count i~ a ~ubstantially accur~tc co~nt 9 r~ t.he total num~ of article~ decantcd or discharged.

1 I T~e sen~or, or t}l~ surface to whiah the sonsor is 1~ coupled, 1~ prefer~ly arranqcd such th~t articl~s 13 leave the s~n~or or ~he 3urfa~e $ubstantially 14 i~mec~i~tely ~fter first impact thereon, ~hereby to ohviate 0~6truction of im~cts ~f subsGquent ~rticlo6.
16 This may be ~lmply ~:hieved by arr~nging that thc 17 sensor or surfa~ U~VlI which the ~rticle~ imp~ct ha~ a 1~ sul~stantial slope such th~ tlle arti~les promptly f~ll 1~ ofL or roll off under qr~vit~y, 21 lf t~le article~ ave in~ivlclual masse~ in a relativoly 22 wide range prior to the ~untill~ oper~tion, the method 23 pre~erably further in~lu~e~ a preliminAry step of 24 sortlng t~e artlcles into ~roups w~erein th~ mas6es of 2.~ ar~ les irl each ~roup lie witnin a relatively narrow 2fi range. Tnis ~rellmlnary s~ will minimise potenti~l 27 di~iCultl~S of ~ lination between a sin~lQ ho~vy 28 arti~le and two l;ght arti.cl~g.

Illhe preS~nt inves~ioll is particularly but not :~1 ex~lusively intended for us~ in a flsh farm to count 32 ~iSII as tney are d~nL~ rrom a t~nk (for examplc in 33 the course of tran~rer to a~other tank, to op~n water, 34 or into ~ purchas~r's contairl~-). The inven~ion may :~5 also be applied to Counting l.ive or ~ead fish ,., , ~

~; 20(~9647 ~a~s~orte~l b~ CVIlvC:y~". be1t~ ~nd is y~tic~ulsr1y pplica~lc tv c vu1lti.ng live fish removcd from a 3 ~.~r eecli~ tank V~ ~ C,OIlVeyOr ~iy:;tem of th~ typc which 1 di:~charrJe t:he Li~ at dif~eren~ vut.lt. t . .sct.ording tv lf~ir ~ize; .~ /Jall~ j sy.stcm pre-acl juste:l to copc with ect~d narrow ranc~c t.~ f i~h 3izes will hc~
7 in~tall~i url~er ~acll c~r~vc:yor outlet to producc ~ cvunt u~ Li iil vL a given eize ~the rangc scttings will be t3 dirft-~el-lt f:rom ~:ne c:ountinc~ sys.tcm to tha next 10 accortli.~c~ t:v wht-l ht-r tl~e r~sycctive co~lntinc~ sy~;tem i.s 11 ~u d~ ;]l Gln~ I .l t'ish or l~rge fish) . The invention 12 wvuld also l::e ,~pplica~le tv c ouslt fi~.h in fishing 1 3 v~;els, fish mar.kt t: i, dlld Li:;h I~Loct sSilly f~ctoric:s.
~ 4 This inven~iorl ic, ,~Lc.o appl.i.cable to Counting ~uite l~j diffe~ el~t al-tic le-s in quit~ <liffer~nt conte~tsi for l? cxam~l e the inventiOn may bc ap~] icd to count;.ng arvosto~l fr.uit. nnc~ veyeta~les, and to counting 1~ mass-~:roclucc~d ct.-.mponents in industry.
~0 Zl ~ -J~Jdi)~lc:llt~s ~11 the invention will now be describ~d, by Z2 way or example, with reference to the ~ccv~panying drc~wint3s, in which:-2~
Z~ l~ig. I i s a schematic diaqram of a basic ~6 ~hysiGal arrnnqem~nt of an article counting 2 7 ~y~ tem;
2a F` i q . ~ n block circuit diagrAm of an ;2'~ artic~.l.n cnunti ng s.y.e:tr~m:
l k~ i.s ~ block di.ngram circuit of nn 31 Altertl~ti.v~ arti.cle countint~ ~.yst~m; And 32 Fig. 4 i5 a gchematic diAqram of a physical 33 ~rl-Anqement for simul~nneous counting of 3~ ,ev~ -A I differel-t sizes of size-qL~aded 3 5 a r t i c~
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7 20C~9647 I ~eferrin~ fir~t to Fi~. 1, a feed ~ipe 10 h~ it~ inlet 2 elld 1~ r~ from ~ tank or hopper GOntaininq th~
3 articles to ~e co~nted. The ~ccd pipe 10 is gener~lly 4 down-~lopin~ such th~t th~ articl~s (not shown~ roll, slide, or tumbl~ ~wn to ca~cadc out o~ tho low~r ~u~let end 14 of ~}~ feed pipe 10 more or le~
7 indivl~iually, ~,ellerally~ one articlc at ~ tim~ will 8 leave ~l~e ~utl~ 14, but some~imes two, or cven thr~e ~ clL ti~J C5 ~ill co~e out to~cthPr.
11 A slopil~ platc 16 forms th~ top pl~te of a closed box l2 17 which ~loats in a re~eiving tank ~9. The ~ 17 i~
1~ arranged to float in th~ ~nk 19 ~ shor~ di~tance bclow 1~ ~nd ju~t bey~rl~ the fee~l yipe outlet 1~. A sen~or 1 in the for~ of a ~icrophone i5 f astened to the lG undersi~le Or the sloping to~ platc 16 to respond to the 17 impact ol artiol~s falling ~nto the plate lG from the 18 ot~tlet 1~. ~rhe ~ut~ut of the sens~r 1~ is ~ tr~tn~icnt 19 osclllatory ele~ iynal whose peak amplitudc i~
proporsional to ~e magnitude of the 3mpact causod by ~I tne La 1 lin~ ar~.icle o~- ar.ticles, and ~ten~e to thc mac~
22 o~ t~e articlc or artivl~ e they f~ hrough n 23 llomin~lly con~tant hcight.

ll~e slope of the ~lçt~e 16 causes the nrticle~ tb f~ll 2~ oll the plat~ lfi wit~lvu~ delhy, leaving the plAte 16 unoh~tructe~ ~u ill-pact ~y aubseq~ently f~allinq 28 articles.

ll~he serl~or 18 may ~ rnatively be Easten~d to the 31 bottom of the ~x 1~ or may be oth~w1se po~itioned 32 within the ~ox 17 to m~xinlise detection of t~c impact, 33 ln another embodiment (llOt 3hown) the sloping plate l~
34 may be a free pla~e, ~ut forming part of ~ny other :~ stru~:ture an~ r~ull ~ iyidly mounte~ a short distancc , : ~ ' .

20(~96~7 low and just beyolld the feed r7ipe outlet 1~.

`3 l~he el~ctri~:~1 out~ut signal fro~ the ~cn~or 1~ is f~A
4 to the ~ir~uit arranyem~llts of Fi~. ~ or Flg~ 3 which 5 will now be describe~ in detail.

7 ln the ~ig. 2 ~rrange~ent, the ~l~ctrical o~tpUt si~nal 8 ~roln t~e Sens~r 18 is fe~ intr.~ a levcl dctector circ~i~
9 20. The circlli.t 20 ~tects which one o~ sevcral con~iguous magnitu~ rangcs the peak sen~or ~igna1 ll f~lls into, and produce~ ~ chara~teristic output signal 1~ accordingly. Ilhe~e magni~u~e range~ are pr~determ~ncd 13 by a calihration and lev~l control circuit 22 connccted 14 to the level detector circ~it 20. Corl~ruls fvrming part of the circuit 22 provide ~witchable settings for 16 overall input from the ~n~or 18, ~nd adjust~ble 17 set~lrlg~ to increase ~r decrease the l~v~ls def inlng 18 the magnitude r~nr~es ~7V~ which the detcctor circuit 20 1~ operates.
~0 ~ he resul~ant cnaracteristk: outL7ut signals from the 2~ ~evel detector circuit ~ operate a counter ~c~u~tor 23 circuit 24 to pro~uce a requi~iL~ num~er of counter ~4 actuation signals ultimately depen~ent on the nu~L of article~ sellsed by the sen~or 18 in conjunction with 2~ the lev~l detector ciroui~ ~o.
~7 28 Control inputs 26 ~onl~ected to the ~ounter ~ctu~tor ~y circui~ ~4 in~lude an ~7n/of control, n re-~.ct control, a COUIlt inhi~it contr~l, u count start/atop control, ~
31 ~rint control fvr printing unit ~ not sho~n), a battery ~,r l)~Ck-Up monit~7r, and an on/off control ~or a tot.~ tor.
3~
~ e output fr~7lll tl~e counter ActUation airCuit 24 20~9647 1 operaLe~ a convetltional uy/~owll ~vcnt co~nter ~8. ~ach Z single ~U11ter a~u~tioll signal from th~ cir~uit 24 3 increm~nts the ~ourlt in the counter 2B ~y one. Thc 4 ~ teGtion o two or more article~. simultalleously 5 hittin~ the plate 1~ wil~ ~sult in ~ corre~ponding 6 num~er of suitably spaced counter actu~tion signals J f r~m ~he circuit ~.4 to incrcment the counter 28 by thc requlsite number. Alternatively, thc counter 28 can bo e~ployed t~ oount d~wrl (ie to increment neg~tively) frvm a pre-set Lv~l such that th~ rcaching oE zero ll inclicate~ ~vm~letion of delivery of a batch of 12 pre-~.ol e~ted siz-3.

14 A~ alterna~ive to the collLrols 26 a~d the oounter 2 l'~ being in ~i~e form of hardware, they co~ld be repl ace~
~ y ~ ~uitabl~ microproce~or-based systcm for l/ sopl~lsticated moni~u~ g al-lcl control. 'rhe control~ 26 l~ w~ulCl then be full~Livnally replaced by a kcyboard, l~ ~hlle the arti~e COUIlt would be displ~yed on an VDU
~lol-lc~ with other ~y3tem parametcrs.

ln the Fig. ~ ~r~ elllellt, ~he eleetrtc~l output ~ign~l 23 rrOm the ~n-;oL 18 i~. pas~ed to an ~mpl.ificr 50 and ,:4 then ~ 3~ ~ ~ l~v~l ~t~tor ~nc- 1~ the forr of .~
5chmitt trig~er. 52 which pl o~UceS an output pulse when the output volLnge received from the ~mplifier 50 i3 27 ~bove a certain threshold. l'he output puls~ from the 2~ Schmitt trigger 52 is passe~ to a controllable 29 monostab].e multlVi~ratOr 54. Ttl~ .,u~u~ ~ulse from the ~u tne multlvi~ra~vL- 54 i~ c~ntrolla~le to give an optimum :~ 1 pulse length. Th~ len~tll of th~ pulse is determined by ~? tl-e size of ttle fish or article being Gounted. I~
33 practi~e, tl~e 1ength vf the ~ulse mus~ bc sufficiently 3~ long to v~viaL~ ~oubl~ counting, but must be ~hort enough to mirlimi~ the dead time of the ;.nstrument.

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20(~9647 1 ~lhe ~ea~l time i~ Lll~ ~ur~tion of the pulse length sincc.?
z clurin~ time nc~ L~L ~ller PU1~.eS maY ~ ~VUnt~d. The ~ out~u~ pulses fL-c~nl ~he multivibrator 5~ .~r~ ~assed to n 4 c~ teJ ~8 ttlrc)uyll the c;ounter riring c;rc-uit 5~.

f.~ Ref~rLitlg llOW to Fi~ . ~, thi~. ~chematioally i.llustrntes a systcm ~or ~ra~irl~3 .IIJ~ Counting ~ re~l rish. A
conveyor ~rlL ~ystcm 30 i~ ed at it~ l~ac3ir-g end 31 ~J ~ h ~rtifici~lly oulturecl live fish whi~h ~re of a 1~ ~in~ ie~ t have ~3rown to a r~n~7~ of size~. A
11 known arranqemt~ c3rad~. the f.i~h into sevcr~l. narrow 12 ranyes of ~ a~ th~y pa~ along th~ ~onveyor system 13 ~0. Fi~ Lel-let~l-mi.ned size rAn~ ar~ c3is~hargcd .-; from the o~rl~y~L 3y~.tcm 30 at vnriou~ point~. 34A, 3~B, 3~C, ~ etc, ea~ t-)articular ~i~c~l~rge ~Oj.llt being lG ~or Otle O~ the ~iZc~ rall~es. Bene~th ~ch flischarge .l~ point 3~A, etc, is a re~pc!c:ti~e non-ric~idly mounted i~3 F.lOping plat:~ or box 3GA, 3~ 6C, 3~.D, etc. Each o~
'! thes~ t~!~. h~s ~ rCc;~ -t i ~e .impar t :;~rl~vr 3 ~
~U ~s~ r~ etc, a~ :ht:~3 ~lleLet,U CJr Witllill thc I~C~X. ~r~}le ;~1 Fi~ yi~teln ~.c~ fnr cle~ rik,Gcl i~s therefor.e ~z furl~:-ic)llally ~uival.ent to Fig. 1 ~y3tem replicated as nl.~ny time~ u~ th~rc are fii~h ~ize rallg~.

~rJ F.uc:l uf tllc ~.ellsc~ri~, 3ffA, etc in ~:ig. 4 ;.~ connccte~l to c.f; 1l Le~ye~tiVC ~oun~inrj~ circl~it arranqement r3s shown in ~ 3. ~ l~r Fi~. 3, or mor~ ~r.e~erably to a modi~ication z~ th~rcc~f. .i rl wlli~ th~a multlpl.e courlting circuits ~3 fur~ or) u;l(leL tll~ colltlol of a ~inqle ~upervi.sory ~o ~uicLu~Ioc~ or c:on~rol ~y~t~m . The ~y~7tem of liig. ~
3. can h~ em~loyt-d, Lur ~xamplc, to audit t~le products of 3z a riSh br~eding t~rlk when thc tank ic. emptled after 33 illitinl ~leeclillcl ~nd prior to ~ale or c,ontinued cultivn~ioll o~ the ~ h.

11 2(~C~9647 1 Analo~ous ~ses of the arti~l~ counting systems of the 2 invention may ~e madc in any context involvin~ article6 ~ (whet~er ~nimate (~r illanimate) whi.cll are capablc o~
4 being manipulated (wh~thel- ~y being dropped or Otllerwi~e) to im~ t upon a sensor (or a surfacc to 6 whi~ a sensor is attached) ~ producc a characteristio 7 si~nal.

~ Tne variou~ articl~ coulltlng ~pp~ratu~, methods, and system~ (lescri~e~ above may l~e su~jected to ~thcr ll modi~iGatiotls and variation~ without departing from the l2 scope o~ thc invelltion.
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Claims (10)

1. An article counting apparatus having a sensor signal input connected in use to a sensor which transduces impact to a proportionate electrical signal, said apparatus further including detector means connected to said input to detect said proportionate electrical signal in use and to produce a characteristic output signal when the magnitude of said proportionate electrical signal lies within a predetermined magnitude range.

2. An article counting apparatus as claimed in Claim 1 and including a counter actuator circuit coupled to receive the output signals of the detector means, said counter actuator circuit functioning in use to produce successively incrementing count actuations when an output signal is received.

3. An article counting apparatus as claimed in either Claim 1 or Claim 2 wherein said detector means is a level detector circuit such as to produce a respective characteristic output signal when the magnitude of said proportionate electrical signal lies within one of a plurality of predetermined ranges of magnitudes, said respective characteristic output signals being mutually distinct whereby to identify the respective range.

4. An article counting apparatus as claimed in Claim 3 wherein said plurality of ranges are contiguous and increase in magnitude from a minimum threshold magnitude up to a peak magnitude.

5. An article counting apparatus as claimed in either of Claims 3 or 4 wherein the counter actuator circuit coupled to receive the output signals of the detector means in use produces successively incrementing counter actuations as the proportionate electrical signal traverses ranges of successive increasing magnitudes, such that the incrementation of counter actuations serves to identify respective ranges of increasing magnitudes.

6. An article counting apparatus as claimed in any one of Claims 3 to 5 and including means for conjointly or independently varying the lower and upper limits of the or each said range of magnitude to allow selective variation of the predetermination of the range or ranges of magnitude such that the counting system can be adjusted to discriminate between the impact of a single article, and the respective simultaneous impacts of more than one article.

7. An article counting apparatus as claimed in any preceding Claim wherein said sensor is a microphone.

8. An article counting apparatus as claimed in any preceding Claim wherein the sensor is coupled to a surface which is impacted by a cascade or stream of the articles.

9. A method of counting articles, said method utilising the article counting apparatus as claimed in any preceding Claim, said method comprising the steps of discharging the articles from a container to impact upon the sensor or the surface to which the sensor is coupled, and operating the apparatus to count the number of impacts such that the count is a substantially accurate count of the total number of articles decanted or discharged.

10. A method as claimed in Claim 9 and including a preliminary step of sorting the articles into groups wherein the masses of articles in each group lie within a relatively narrow range.