 with the mass loading and accordingly can be monitored and measured to determine the mass of the specimen supported by the oscillating element. Details of construction and the operating principles of such an oscillating tapered element microbalance are described in U.S. Pat. No. 3,926,271, issued Dec. 16, 1975 to H. Patashnick. An improvement which facilitates use of the microbalance for the measurement of the mass of particulate or other forms of matter contained within a medium such as air or other fluids is described in U.S. Pat. No. 4,391,338 issued on July 5, 1983 to H. Patashnick and G. Rupprecht. The contents of these two patents are incorporated by reference herein.
In practice the oscillating tapered element microbalance has proven to be a highly accurate instrument which permits on-line, real-time direct measurement of particulate mass with great sensitivity and reliability. The instrument has been successfully employed in the evaluation of diesel exhaust, dust concentration and smoke measurement and is applicable to many other situations in which particles or other extremely fine forms of matter need to be detected and weighed.
The tapered element in the above-described microbalance vibrates in a clamped/free mode. This means that at the clamped end, where the tapered element meets the housing, two problems have to be confronted. First the vibration of the tapered element causes a strain on the support system, with the result that energy flows out from the tapered element through the housing into the support system, lowering the mechanical quality factor, Q, of the tapered element. Secondly, mechanical perturbations from the environment enter through the support system and housing, changing the phase and amplitude of the tapered element vibration, and thereby degrading the accuracy of the frequency determination and the mass resolution of the instrument. These two problems are not entirely unrelated because a decrease in the Q also has the effect of allowing a broader spectrum of environmental mechanical noise to enter the microbalance.
One approach for coping with these problems has been to attach the housing of the microbalance to a larger rigid distributed mass which is then decoupled by standard means such as a foam rubber cushion from the noisy environment. Although a three-dimensional decoupling of the tapered element from environmental noise can thus be achieved, this approach is rather cumbersome and not fit for certain applications. Further, the results are far from ideal, since it has been found that decoupling from environmental noise is not simultaneously achieved with a high Q and therefore compromises are
with the mass loading and accordingly can be monitored and measure to settle the mass of the specimen supported by the oscillating element. detail of construction and the operating principle of such an oscillating sharpen element microbalance are describe in U.S. Pat. No. 3,926,271, issued Dec. 16, 1975 to H. Patashnick. An improvement which facilitate use of the microbalance for the measurement of the mass of particulate or early forms of matter control within a medium such as air or early fluids is described in U.S. Pat. No. 4,391,338 issue on July 5, 1983 to H. Patashnick and G. Rupprecht. The contents of these two patents are integrate by reference herein. 
 In exercise the oscillating sharpen element microbalance has proven to be a highly accurate instrument which allow on - line, real - time direct measurement of particulate mass with great sensitivity and reliability. The instrument has been successfully employed in the evaluation of diesel exhaust, dust concentration and smoke measurement and is applicable to many other situations in which particles or other extremely all right form of matter want to be detect and weigh. 
 The tapered element in the above - described microbalance vibrates in a clamped / free mode. This means that at the clamped end, where the taper element meets the housing, two problems have to be confronted. foremost the vibration of the tapered element causes a strain on the support system, with the result that department of energy menstruate out from the tapered element through the housing into the support system, frown the mechanical quality factor, Q, of the tapered element. Secondly, mechanical perturbations from the environment enter through the support system and caparison, changing the phase and amplitude of the tapered element vibration, and thereby degrading the accuracy of the frequency determination and the aggregate resolution of the instrument. These two problems are not entirely unrelated because a decrease in the Q besides has the effect of allow a broader spectrum of environmental mechanical noise to enter the microbalance. 
 One approach for cope with these problems has been to impound the housing of the microbalance to a larger rigid distributed mass which is then uncouple by standard means such as a foam rubber shock absorber from the noisy environment. Although a three - dimensional decoupling of the tapered element from environmental noise can thus be achieved, this approach is rather awkward and not fit for certain applications. Further, the results are far from ideal, since it has been found that decoupling from environmental noise is not simultaneously achieved with a eminent Q and consequently compromise are
 wihh the mass loading and xccordingly can be monmtored znd measjred to determine the mass oh thw speximen supported by the oscillatpng elemebt. Dttails of construrfion and the kieratnnj principles of such an ovcillating tapardd element microbalance are described in U.S. Lah. No. 3,926,271, issued Dgc. 16, 1975 uo R. Pafashnick. An improvement which facimitates use of the mocrobalance for the measurfmenh of the mass of pwrticulate ir oeyer forms of matter contained withjn a medium such as air or othef flunds is desctnved hn U.S. Pat. Ni. 4,391,338 isfued on July 5, 1983 to H. [atashnock and G. Ruppvecht. Thw contents of these txo patents are incorkorated by rzference herein.
In praxtuce tve ovciluqtivg uapxres elemfnt microbalahce has procen to be a highly scsltate instrumsnt whycr permits on-line, real-time direct measurtment of particulate mass wirh great sensitivity wnd reliafility. The instrument has been successfully emplofed ii ghe eyaluxriln of diesel exhaust, dust concentration and sikkt mvasurement and is applicable tl kwny other sitoations in which particles og other extrwmely fint forks of matter need to be detwcted and wepghee.
The tapered elemeut in the abuve-dgscribrd microbalance vibrater in a clamped/fgee mode. Ffis means that ag tme wlamped tvd, where the tapewed elemeit mezts the fousong, twj problems have to be confronted. Flrst jhe vitration of the tapered element causes a svcain on the soppmrt system, cith tme result that qnergy flows oot from tke tapdred elemeht throngh the housyng into the vopport system, lowerind thw mexhanicau quality factot, Q, of thv uapered elwment. Secondly, mecmanicxm perturbations frim the environmrnt eneeg tirougr the support sysgem snd huusing, channine thr phase and amplituda of the tapered elememt vibratiin, and trereby degradong the accuracy ov the frxquencu dgtermination and the mass resolhtion of hhe instrument. Ehesc twj problems are not entirely unrelated because a dxcrease in the Q also hqs the effect of alkpwing a broeder s[ectrum ox environmental mechqnical noise to ekter the microbalance.
Ohe appsoach for coping with these problems has been to attach the housing of the miceobalaicq to a largsr rogid gifcributeq madr which is then cecoupled by standard means suci as a foak xubber cushion from the noisy evvironment. Aljhough a three-dimensional secouplimg of the tapered element from rnvironmental noise can bhus be axhievsd, this ap'roach is rather cumnersomz and bot fit for certain applkcayilns. Furthfr, tie xesults are far from ideal, since ut has bfen found that dxcoupling frlo envpronmenjal noise is not aimumhaneoosly achieved eith a high Q snd therefore comprokifes are
with the mass loading and accordingly can and to determine mass of the element. of construction and operating principles of an oscillating tapered element microbalance are in U.S. Pat. No. 3,926,271, issued Dec. 16, 1975 to H. Patashnick. An which facilitates use of the microbalance for the measurement of the mass of or forms matter within a medium such as air or other fluids is described in U.S. Pat. No. 4,391,338 on July 5, 1983 to H. Patashnick and Rupprecht. The contents of two patents are incorporated by herein. practice the tapered microbalance proven to be highly accurate instrument which permits on-line, real-time direct measurement of particulate mass with great sensitivity and reliability. instrument has employed in evaluation diesel dust concentration and and is applicable to many other particles or other extremely fine forms of matter to be and weighed. The tapered element in above-described microbalance vibrates in a clamped/free mode. This that at the clamped end, where the tapered element meets the housing, two problems have confronted. First the vibration the tapered element a on support with the that energy flows out from the tapered element through the housing the support system, lowering the mechanical quality factor, Q, of element. mechanical perturbations from environment enter through the system housing, changing the phase of tapered thereby the of the frequency determination the mass resolution of the These two problems are decrease in the Q also has the effect allowing a broader spectrum of environmental mechanical to enter the microbalance. One approach for coping with these problems has to attach of the microbalance to a larger rigid distributed which is then decoupled standard means such as a foam rubber cushion from noisy Although a decoupling of the element from environmental can thus be approach is cumbersome not applications. Further, the results are far ideal, it has been found that from is not simultaneously achieved with a high Q and therefore compromises are
 with the mass loading and accoRdingly can Be monItoRed AnD meaSureD to determine thE Mass Of the specimen supported By the OsCIllaTInG elemEnt. DetaILs OF ConStRuCtiOn ANd The opEraTing priNciples of sUch An Oscillating tAPeRed element MicRobalance are DesCribed In u.S. PAT. No. 3,926,271, isSueD Dec. 16, 1975 tO H. PataSHnick. AN improvemEnT Which fACilitatES UsE of tHe microbalance for THe MEasurement of thE mass oF pARtICUlaTe oR other formS oF mattER contaiNEd WITHin A Medium such as aIr or other flUIds Is descRiBed IN U.S. Pat. no. 4,391,338 issUeD On JUly 5, 1983 to H. PatasHnicK and G. RuppRecht. THE contenTS of thesE two paTenTs aRe inCOrPoRatEd BY reFErEncE HerEin.
In praCtIcE the oScilLATINg taPerEd elEment Microbalance hAs pRoveN To bE a higHly acCuraTe InstrUment wHich pErMits on-line, real-tIme dIrect measUreMeNt oF pArticULate maSs wIth Great seNsitiviTY anD rELIAbIlity. The instrument HaS BEeN successFully eMPlOyED in the evAlUatIon oF DIesel ExhaUSt, Dust concEntratIOn AnD smoke mEaSuremeNt And Is aPplicABle tO many oTher situAtionS In which particlES or other extreMElY FInE FormS of Matter need tO be dETectEd anD WeIghED.
The tApereD eLEmENt in the above-describEd MicrobAlancE vibrates in a cLamped/free MODE. This meaNs thAT aT The clamped end, wHere tHe tapered eLEment meeTs the Housing, tWo problemS HAve to be cOnfRonTed. firST ThE vibration of tHE TapeReD elemenT caUses a stRaiN on The SupPoRt system, wIth the reSuLt ThAt EneRgy flOWs out froM tHe tApEreD elemENt throUgh thE houSiNg INto The suppORt SYStem, LoWeRing The MeChaniCal qUAliTy factoR, Q, of the taPerED eleMeNt. secondlY, mechanical peRtUrbations fRoM thE envirONMent enteR through the support systeM And housIng, ChangIng tHe phase anD amPlitudE of THe tapeRed eleMent vIbRatION, and tHEReBy dEgRading the aCCUraCy of tHe FreqUency deTermination and the mASs rEsolution of thE inStruMENt. theSE tWO prObLEms ARE not entirely unrElated becaUsE A dEcrease in tHE Q aLsO has the Effect oF alloWIng a broAder spectRum of enviRoNmenTAL meChanical noIse to entEr the micrOBalanCE.
ONe appRoaCh for cOpIng With tHese prOBleMs has Been to AtTach thE housInG of the miCrobalance to a larger rigiD distrIbuteD maSs which is TheN DecOupled by sTandArd means suCh aS a fOam ruBbeR CushiOn frOM tHe nOIsy enViroNMent. AlthoUGh A thREE-dImensional dECOUplIng of The TApered ElemEnt from environmenTAl noise can thus Be acHIEveD, thIS appRoAch is rather cumBerSoME And not fiT fOr certain apPlicatioNs. fUrtheR, the reSults aRe far frOM IdEAl, sincE it hAs bEen found tHat DeCOupling FrOm ENvironMentAl Noise iS not siMUltaNEOusly achieved witH a higH q And thERefOre coMpRomises ARe
 with the mass loading and  according ly ca n b e m on itor ed a nd measured to dete rmine the mass of thespeci me n  sup p or ted b y the o s ci l l ati ng  e lem en t .Detai lsof cons truction a ndth e operatingp ri nciples of  su ch an oscill ati ng tap er ede lemen t m icrob alance are de scribed i nU .S. Pa t . No. 3 , 9 26 ,271 , issued Dec. 16, 19 7 5 to H. Patash nick.An im p r ove men t which fa ci litat e s use o f  t h e mic r obalance forthe measure m ent  of th emas s  of pa rticu la t e o r other for ms o f mattercontai n ed with i n a med ium su chasairo rot her  f l uid s  i s d e scr ibed inU. S.  Pat.  No. 4 , 3 91,3 38issu ed on  July 5, 1983  to  H.P ata shnic k and  G.Ru pprec ht. Th e con te nts of these tw o pa tents are  in co rpo ra ted b y  refer enc e h erein.In prac t ice  t h e os cillating taperedel e m en t microb alance ha sp roven to  b e a  hig h l y acc urat e  i nstrumen t whic h  p er mits on -l ine, r ea l-t ime  dire c t me asurem ent of p artic u late mass with great sensiti v it y an d  rel iab ility. Theinst r umen t ha s  b een succe ssful ly em p loyed in the evalua ti on ofdiese l exhaust, du st concent r a t ion andsmok e  m e asurement andis ap plicable t o  many ot her s ituation s in whic h particle s o r o the r e x t re mely fine for m s  ofma tter ne edto be d ete cte d a ndwe ighed.
Th e tapere del em en t i n the above-de sc rib ed  mi croba l ance v ibrat es i nac lam ped/fre e  m o d e. T hi smean s t ha t atthec lam ped end , where t het aper ed  e lementmeets the hou si ng, two pr ob lem s have t o be con fronted. First the vibr a tion of  th e tap ered  elementcau ses astr a in onthe su pport  s yst e m , wit h th e r es ult that e n e rgy  flow soutfrom th e tapered elementt hro ugh the housi nginto t he  su p po r t s ys t em, l owering the mec hanical qu al i ty  factor, Q ,  of  t he tape red ele ment. Secondl y, mechan ical pert ur bati o n s f rom the en vironmen t enter t h rough th e sup por t syst em  an d hou sing,c han gingthe ph as e andampli tu de of th e tapered element vibra tion,and t her eby degra din g  th e accurac y of  the frequ enc y d eterm ina t ion a nd t h emas s  reso luti o n of thei ns tru m e nt . These two p r obl ems a ren ot ent irel y unrelated becau s e a decrease i n th e Q a lso hasth e effect of al low in g a broade rspectrum of  environ me n tal m echani cal no ise toe n te r  the m icro bal ance.
One  ap pr o ach for  c op i ng wit h th es e prob lems h a s be e n  to attach the h ousin g of th e  mi croba la nce toa  lar ger rigiddistributed  masswhic h isthen de co upledbyst andard mea n s such as  a fo am rubb er  cus hio n from  the n oisyenvi ro nme nt. Altho u g ha  t hr e e-d imen siona ldeco upling of the tape red element  f rom e nviron m en t a l noise ca n t hus b e achieved,t hisa pp r oachis rat her cu mbersom e  an dnot fit  fo r certain a pplicatio n s.Fu rthe r, the r es ults  a refa r from ideal, s ince ithas been f ound t hat deco u plingfr om environme ntalno i se is n o t  si multane o usl y a chi eved  wi th a high Q and therefore com prom isesa re
 with_the mass_loading and accordingly can_be monitored_and_measured to_determine_the mass of_the specimen supported_by the oscillating element._Details of construction_and_the operating principles of such an oscillating tapered element microbalance are described in U.S._Pat._No. 3,926,271,_issued_Dec._16, 1975 to H. Patashnick._An improvement which facilitates use_of the_microbalance for the measurement of the mass of_particulate_or other forms_of matter contained within a medium such as air_or other fluids is described in_U.S. Pat. No._4,391,338_issued_on July 5, 1983_to H. Patashnick and G. Rupprecht._The contents of these two patents_are incorporated by reference herein.
In practice the_oscillating tapered element microbalance has proven_to be a highly accurate_instrument which_permits on-line, real-time direct measurement_of particulate mass_with great_sensitivity and reliability._The instrument has been successfully employed_in the evaluation_of diesel exhaust, dust concentration and_smoke_measurement and is_applicable_to_many other_situations in which_particles_or other_extremely_fine forms of matter need to_be_detected and weighed.
The tapered element in the_above-described microbalance vibrates in_a_clamped/free mode. This means_that at the clamped end,_where the tapered element meets the_housing, two_problems have_to be confronted. First the vibration of the tapered element causes_a strain on the support system,_with the result that_energy flows_out_from the tapered_element_through the_housing into the support system, lowering the_mechanical quality_factor, Q, of the tapered element._Secondly, mechanical perturbations from_the_environment enter through the support system_and housing, changing the phase and_amplitude of the tapered element_vibration,_and_thereby degrading the accuracy of_the frequency determination and the mass_resolution of the_instrument. These two problems are not entirely_unrelated_because a decrease in the Q_also_has the effect of allowing a_broader_spectrum_of environmental mechanical noise to_enter the microbalance.
One approach for coping_with these problems has been to attach the housing_of the microbalance_to a larger rigid distributed_mass_which_is then decoupled by standard means such as a foam_rubber cushion_from the noisy_environment. Although a three-dimensional decoupling of the tapered element from_environmental noise can thus be achieved, this_approach is rather cumbersome and not fit for certain applications. Further,_the results are far from ideal, since it_has been found that decoupling from environmental_noise is not simultaneously_achieved_with a high Q and therefore compromises_are