Laserfiche WebLink
BULLETIN N0. H-11 <br /> J <br /> Jun VM00 S <br /> WITH THE D R PITOTTUMNE <br /> AIR VELOCITY <br /> TIn tata I pr■ssure of an air sit at flowing In a duct is the Barn of the static ar bursting pressure exerted <br /> open the sederrails ei the duct and the impact or vvioearr pressure of rhe movtaq asr. Theenh the use of a <br /> p,rar tube cnnnectsd diffrrrntsaliy to a Manama! r, the velocity pressure aloito is Indicated and file car. <br /> respandinq air velocsty datorminad. <br /> For accuracy of plus or manus 2:,as in laboraTory applications, exmm* care is required and the following <br /> prvcautions should be observed: <br /> 1. Cuct diameter 4" or 91 ter. �� ....�+•••��• <br /> 2. Make an accurate "law rse per skest6n at <br /> right, calculate the veleaties anti av- <br /> a � I <br /> *rage the readings. • <br /> 3. <br /> • E Praviae smcath. straight duel sections <br /> I "fit r s s <br /> a rnrnirriurte of 8381 aiarnarars in lextgth • i <br /> upstream and 1 th aiamorers down- �c ..+, �' •� <br /> arearre frarn rule pilot tub it.A. Provide Provide an egg crate r/pe straighlerser <br /> upstream from the prrar tube. <br /> moiung an air vviocsty check select a ioeatton as suggested above, connret tubinq leads from barft pilot <br /> e caa044mons m the seanomilror ani easatt icy the duct wlih the ftp direetsi into the air stream. If the <br /> Tnpefflater shears a Torous i4dicsition reverse the tubes. With a direct reading itanomater, air .eiaestses will <br /> now be show" lir Feet per arinvtt. lie Omar types, tris aaasdisri+er will react velocity pressors its inches of <br /> .rarer acid the carrespona.mq velocitr .rill be fowed from the curves i4 this 111111114ft- If cireirmst+aroas do <br /> not Qarnttt an aecsir0te traverse+, canter the pitwe tube tet the duct, datereneaa the center vulacitp aaii suif- <br /> ply 6y a Factor of .9 for lire approzsatatr ovarog• velocity. Field tests rue in this manner should bs ac. <br /> auraft within plias or nuns 5!L <br /> ,raw vsiacity Iniicutad is for dry air at 70'f., 29.9" Soramaimc Pressure and a resuiflag okazaty of .075:/ <br /> cu. ft. Far air at is tocipinature other than 70'F. reior to the carves is this oullettn. For anter vattatsans <br /> frame these code ifi4ns, cnrrecnans may be based 0944 the* Following iota: <br /> r­o <br /> A;r Veaoctrr- 1046-2 <br /> 0 <br /> where Pv s veiectry► presswe in utdees of wetar <br /> 0=Ase ife"ry m ;;/cu. ft <br /> Air 0anury s, i.325 : h <br /> ••here ft—daramorme Frame ;a inchas of n.vairT <br /> T—Absolrrtet Temp re ('indicates terapirretwo 'F <br /> Olga 4601 <br /> now on at. h per +nit+_ Mauer arra ;n swore fief x err "Mary .a h <br /> ger mm. <br /> AIR YELCC1TT STAJmLESS STEEL <br /> Q&6=LAT0R PiTOT TusE S <br /> ' Z. .rr.�++i Tri. eaw...mm d wen Caw <br /> • err .ir •wa•tq .�! rriiarr•r mod I4i•rr.,ur r� <br /> MW es.r.i».wi ri �wsrrf steure•an •r Ms.SOA fi�rn' <br /> �warrrr. Eliiwr. <br /> loss .r+ri. I A e ti <br /> Rome h a v e r r c e i c%. su.w• sr.w J�iir <br /> I r r w.r s s w e+ <br /> wearCrrMrl.��r�i► .►i��hver <br /> r r lo, -+�+� �.wssra. <br /> to .oQ » AM.Q40 apt+. iStfR.►E Load 54 s. <br /> rev—&food .niftwacm .... S:i�i Z�- A ha lever. <br /> 'r -,M. - "dov" or i.ors n► <br />