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RT I Projec t No . 893-6 6 July , 197 6

EXAMININ

GTH E PROPERTIE S O F QUALIFIEDOBSERVE R OPACITYREADING S AVERAGEDOVERINTERVAL S

O F LES S THA

N SI XMINUTE S

Prepare dfo r Environmenta l ProtectionAgency ResearchTriangl e Park , Nort hCarolina 2771 1

Contrac t No . 68-02-132 5P. 3

RT I Projec t No . 893-6 6 July , 197 6

EXAMININ

G TH E PROPERTIE S O F QUALIFIE D OBSERVE R OPACITY READING S AVERAGE D OVE R INTERVAL S

O F LES S THA

NSI X MINUTE S

b y Tyle r D . Hartwel l Researc hTriangl e Institut e Researc hTriangl e Park , Nort hCarolina 2770 9

EP AProjec t Officer : RoyNeulich t

Prepare d fo r Environmenta l Protectio n Agenc y Researc hTriangl e Park , Nort hCarolina 2771 1

Contrac t No . 68-02-132 5P. 4

TABLE O F CONTENT S
Pag e 1 . INTRODUCTION . 1 2 . DESCRIPTIO

N O F DAT A 2 3 . DATA

ANALYSI S 4 4 . SUMMAR

Y1 6 REFERENCE S 2 0 APPENDI XA : Frequenc y Distribution s o f MeanDeviation s APPENDI XB : Frequenc y Distribution s o f MeanObserve d Opacity Whe nMeanTru

e Opacity

Les s Tha

n 2 0 Percent an

dMeanTru

e Opacity

Les s Tha

n1 0 Percent APPENDI Xe : Estimatio nof th e Measuremen t Error o f a n Observe rP. 5

1 . INTRODUCTIO

N

In197 3 an

d197 4 EP

A conducte

dsevera l fieldtest s fo r th e purpos e
o f studyin

g th e performanc e of qualifie dobserver s invisuall y assignin

g opacit y to stationar

y source s usin

g procedure s set forthi nEP A Referenc e Metho d9 . Previou s analysi s o f th e dat a fro

m thes e fieldtest s i s pre sente din[1 ] an

d[2] . Inthi s report , a descriptio ni s give

nof addi tiona l statistica l analysi s b y th e ResearchTriangl e Institut e (RTI ) of dat a fro

m tw o of th e EP A fieldtests . Th

e reaso nfo r th e current research
wa s th e following : a t th e present tim

e Referenc e Metho

d9 state s that complianc e of th

e opacit

y standar

dwil l b

e base do na naverage o f 2 4 consecutiv

e opacit

y reading s ( 6 minutes ) take nat 15-secon

dintervals ; however , man

y stat e an

dloca l standard s are inconsistent wit ha standar d base do na 6-minut e averagin g time . Thus , EP

A aske dRT I t o investigat e th e effec t of usin

g averagin

g time s o

f les s tha

n6 minutes . Accordingly , thi s repor t present s a nanalysi s designe

dt o examin

e th e effec t o f different averagin

g time s o

nsevera l different statistic s suc ha s th e frequenc

y distributio

nof meanobserve

dopacity . Inthi s report , Sectio n2 describe s th

e dat a that RT I analyzed , Sectio n3 present s RTI' s analysi s an dSectio

n4 give s a summar

y of th e results .P. 6

2 . DESCRIPTIO

N O F DAT A

Th e dat a analyze

dinthi s repor t wer e collecte db y certifie

dobserv er s wh o visuall y

determine

dth e opacit

y of emission s fro

m stationar

y
source s durin

g tw o EP A fieldtests . Th

e procedure s use

dt o gather thes e dat a ar e set forthi nEP A Referenc e Metho

d9 (se e [1]) . A

detaile

d descriptio

nof th e fieldtest s i s give nin[1] . Inbrief , th e field test s wer e th

e following : (i ) A tes t conducte

dNovember 19-20 , 197 3 a t th e Nationa l Environmenta l Researc hCenter , Researc

hTriangl e Park , NorthCarolin

a usin g tw o smok e generator s with9 certi fie dobserver s (denote dhereafte r a s th

e Smok e Generator Test) , (ii ) A tes t conducte

d3 0 September - 1 October , 197 4 a t th e Riverben

dStea m Statio nnear Charlotte , NorthCarolin a usin g 8 qualifie

dobserver s (denote dhereafte r a s th

e Stea m Statio nTest) . Not e that fo r th e Stea m Statio n Tes t only

4 o f th

e observer s collecte ddat a a s specifie

d specifically

inReferenc e Metho d9 ; an dtherefore , only dat a fro

m thes e 4 observer s ar e analyze dinthi s report . The basi c procedur e i neac ho f th e two - fiel dtest s wa s to hav e eac h observer assig

nopacitie s t

o plume s a

t 15-secon

dinterval s fo

r a tim e perio dof 6 minute s (define da s a run) . Thus , a ru nha da tota l of 2 4 observation s b

y eac hobserver . Fo

r eac hfiel dtes t severa l run s wer e observed . To determin e ho w accurat e th

e observer s were , th e plume s wer e als o measure

db y a nin-stacktransmissometer . Thus , fo r eac hru nthere
wer e 2 4 observation s fro m eac hobserver an

dfro m th e transmissometer .P. 7

Specifically , th

e number of run s fo r eac hof th e fieldtest s were : (i ) Smoke Generator Tes t • 2 0 run s withwhit e smok e an d 1 6 run s withblack smoke . Sinc e eac hru nwa s ob serve db y severa l observers , thi s resulte dindat a
o n17 0 run s wit hwhit e smoke an d13 3 run s wit hblac k smoke . (Note , observe r 9 didnot participat e i n al l of th

e runs. ) (ii ) Stea

m Statio nTes t a 2 4 run s wit hwhit e smoke . Thi s resulte dindat a o

n9 6 run s (=

» 2 4 x ' 4) . Th e tota l number of reading s analyze db y RT I (i.e. , th

e number of 15 -
secon dreadings ) over al l run s an dobserver s an

dbothfieldtest s wa s equa l t o 9,57 6 (17 0 x2 4 + 13 3 x2 4 + 9 6 x24 ) readings . Th e range of th e tru e opacitie s (a

s measure

db y th e transmissometer ) studie ddurin g thes e fiel dtest s wa s between0 an d5 0 percent wit hth e majority

of read ing s bein

g les s tha

n3 0 percent opacity . The dat a o

nth e tw o fiel dtest s wer e supplie dt o RT I b y EP A i nth e for m o f observe r cod

e sheets . RT I the

ncode dan dkeypunche

dthes e dat a ont o computer cards . Eac hcomputer car

dcontaine

da 15-secon

dopacity readin g b y th e transmissomete r an dth e correspondin

g 15-secon

dreading s b y eac hobserver . Ther e wer e a tota l of 1*50 0 computer cards . RTI' s analysi s o f th e opacit

y dat a i s give

ninSectio

n3' . Th

e majority

of th e computation s necessar y fo r thi s analysi s wer e carrie d

ou t b y usin g th e SA S Computer Package [3] .P. 8

3
. DAT AANALYSI S

I n orde r t o asses s the effec t o f variou s averaging time s o n observe d opacit yreadings , RT I use d the dat a describe d i n Sectio n 2 fo r th e Smok e Generato r an

d the Stea

mStatio n Test s and.compute d th e following statistic s fo r differen t averaging time s an d variou s range s o f mea n tru e opacity
. (Note , throughou t thi s sectio n the ter m"mean tru e opacity " refer s t o the
mea n o f the 15-secon d reading s b

ythe in-stac k transmissomete r whic hcor respond s t o the mea n o f th e 15-secon d reading s b

yan observer ; e.g. , i f

a n observe r mea n i s base d o n 4 contiguou s 15-secon d reading s the n the cor responding mea n tru e opacit yi s base d o n th e same 4 contiguou s 15-secon d reading s b

ythe meter. )
A . Frequencydistribution s o f mea n deviation s (observe r
mea n - tru e opacit ymean)
. B . Frequenc ydistribution s o f mea n observe d opacity
. C . Estimate s o f the bia s o f an observer' s readings
. D . Estimate s o f the standard deviatio n o f an observer' s bias
. E . Estimate s o f a n observer' s measuremen t erro r (i.e. , the estimate d standard deviatio n o f a n observe r i n repeate d measurement s during the same run)
. Th e abov e statistic s wer e compute d using the dat a fromal l run s an d observer s wit hseparat e computation s being carrie d ou t fo r (a ) th e Stea m Statio n Tes t (whit e smoke) , (b ) the blac k smok e dat a fromthe Smok e Genera

to r Test , an

d (c ) the whit e smok e dat a fromthe Smok e Generato r Test . Th e averaging time s examine d wer e 3 0 seconds , 1 minute , 2 minutes , ... , 6 min

utes . Th e initia l computation s wer e fo r contiguou s averaging time s (e.g. ,a 1-minut e contiguou s averagin g tim e wa s obtaine

db y averagin

g 4 contigu ous singl e 15-secon dreadings) . Inaddition , statistic s A , B , an dD wer e als o compute

dfo r contiguou s averagin g time s after takin g th e averag e
of tw o observer' s reading s (thi s wa s only don e fo r th e Stea m Statio n Test) . Finally , statistic s A , B , C an dD wer e compute

dfo r th e meano f th e highes t 2 , 4 , 8 an d1 2 non-contiguou s singl e 15-secon dreading s inth

e 6-minut e observatio nperiod s (runs) . Thes e computation s wer e carrie d
ou t becaus e man

y state s hav

e th e followin

g standard : "a

nopacit

y o f Y percent i s not t

o be exceede

dmor e tha

nXminute s pe

r hour " (e.g. , X= 3 'o r 4 minute s per hou r ar e common) . Th e result s of computin g th e statistic s A

throug hE ar e discusse

din th e followin

g paragraphs . Whe

nexaminin

g thes e statistic s i t shoul db e kep t lnmin dthat th

e sampl e size s (numbe r of means ) upo

nwhichth

e statistic s ar e base dar e quit e different fo r th e variou s averagin

g times . Thi s i s du e t o th e fac t that sinc e a ru nconsiste

dof 2 4 readings , contiguou s averagin g time s of 3 0 second s u pt o 3 minute s ha

dmor e tha

non e mea navailabl e fo

r
eac hobserve r per ru

n(e.g. , fo

r th e 30-secon

daveragin

g tim e there wer e 1 2 mean s fo

r eac hobserver per ru

nwhil e fo

r th e 6-minut e averagin g tim e onl y 1 meanpe r observe r per ru nwa s available) . Thus , th e sampl e size s fo r 6-minut e an

dnon-contiguou s averagin g time s are muchsmaller tha nfo r 30-secon

daveragin

g time s (se

e Appendi xA

fo r th e sampl e size s available) . A . Frequenc

y Distribution s o f MeanDeviation s Appendi xA

present s a detaile dsummar

y of th e frequenc

y distribu tions of mea

ndeviation s b

y variou s range s of mea ntru e opacitie s (Tabl e A-2 ) an dover al l mea

ntru e opacitie s (Tabl e A-l) . However , sinc e EP A i s particularl y

intereste

dinpositiv

e mea ndeivations , Tabl e 1 pre sent s th

e percent of th

e frequenc

y distribution s fo

r mea ndeviation s

### I I I I I (

Tabl e 1
. Percen t o f Frequenc yDistributio n fo r Mea n Deviations — 2 / Sinok e Typ e an

d Mea n Tru e Opacity — 

## i / 

## > i

## » I ' . 1 J• 5 Percen t Opacity ; B yAveragin g Time , Station ,

Mea n Tru e Opacit y(% ) 0-1 0 10-2 0 20-3 0 30-4 0 3 / Overall- 7 3 0 sec .

% 5. 9 9. 9 6. 8 3. 6 7. 2 1 min
.

%

. 8 6. 6 5. 1 1. 2 4. 7 Contiguou s Smok e 1

Reading s Averagin g Time 2 min
. 3 min
. 4 min
. % % % 0. 0 6. 1 3. 0 0. 0 3. 3 0.0 *

2. 7 1. 3 2. 0 0.0 * 0.0 * 1. 9
. 8 Generato r

5 min
. %
1. 1 0.0 *

. 8 , Blac k Smok e
6 min
. %
1. 2 0.0 *

. 8 N o Highes t 2
34. 5 17.0 *
23. 4 n-Contlguou s Read i

Averagin g Tim e Highes t Highes t 4 8
22. 4 10. 5 9.1 * 6.5 *

0.0 * 14. 2 7. 1 ng s

Highes t 1 2
4. 5 2.4 * 0.0 * 3. 1
0-1 0 10-2 0 20-3 0 30-4 0 Overal l 13. 1

15. 9 5. 3 1. 1 11. 7 9. 0

13. 2 4. 1 0. 0 9. 0 8. 1 11. 7 4. 9 0.0 * 8. 1 12. 0

9. 8 1. 7 0.0 * 8. 3 Smok e Generator ,

4. 0 15. 8 2.9 * 8. 9 3. 9 14. 5 0.0 * 7. 6 Whit e Smok e

0.0 * 13. 1

7. 1 28. 4

23.7 * 0.0 * 26. 7 36.3 *

30. 4 12.5 *
' . 23. 1 •___

— 25. 0 11.9 * 18. 8 4.0 *

24. 1 6.2 * 15. 1 O k
' 0-1 0 10-2 0 20-3 0 30-4 0 Overal l 11. 7

5. 2 10. 8 9. 8 9. 5 7. 9

5. 8 10. 7 7. 8 7. 6 10. 8

0. 0 11. 6 5.0 * 7. 3 Riverben

d SteamStation , Whit e Smok e 11. 2 0.0 * 7.1 * 3.1 * 6. 2 12.5 *

0.0 *
6. 2 10.0 *

0.0 *

5. 2 10.0*

0.0 * 5.0 * 5. 2 36.0 *

29.6 *
25. 0 26.5 *

26.7 *
22. 0 15.8 *

46.1 * 10.0 * 11. 5 15.0 *

0.0 * 10.0 * 8. 4 Riverbend Stea

mStation , Whit e Smoke , Averag e o f Tw o Observer s 0-1 0 10-2 0 20-3 0 30-4 0 rai l 7. 4

2. 2 11. 0 7. 1 6. 3 5. 0

2. 6 11. 9 6. 2 5. 6 5. 0

0. 0 14. 1 1. 7 4, 9 6. 7

0. 0 11.9 * 4.2 * 5. 2 6. 7

0.0 * 8.3 * 0.0 * 4. 2 6. 7

0.0 * 8.3 * 0.0 * 4. 2 6. 7

0.0 * 10.0* 4. 9

—Mea n Deviation s =• Observe r mea n - tru e opacit ymea n wher e tru e opacit ymeasure d b ya transmissometer
. 2 /

—Non-Contiguou s Highes t 2 = » mea n o f highes t 2 non-contiguou s singl e 15-secon d reading s i n a 6-minut e observatio n perio d (i.e. , i n a run)
. Contiguou s 3 0 sec . =• mea n o f 2 contiguou s singl e 15-second readings
. 3 /

—Overal l = ove r al l level s o f mea n tru e opacit y(se e Tabl e A-l)
. * = Sampl e siz e betwee n 2 0 an d 5 0 observations
. (Note , sampl e siz e a numbe r o f sampl e means )

—= Sampl e siz e les s than 2 0 observations
. (Note , the sampl e size s var ya grea t dea l fo r the variou s averagin g times , se e Tabl e A-2. )

oP.1 1

whichar e greater tha n5 % opacit

y b y averagin

g time , station , smoke typ e
an drang e of meantru e opacity

— . Th e result s are give

nfo r averagin

g time s base

dupo ncontiguou s an

dnon-contiguou s readings . Tabl e 1 (as doe s Tabl e A-3 ) indicate s th e followin

g (note inTabl e 1 that a * indi cate s that th

e frequenc

y distributio

ni s only

base do nbetween2 0 an

d 5 0 means) :

(i ) Ingeneral , a s averagin g tim e increase s th

e percent
of th e frequenc

y distributio

ngreater tha

n5 % opacit y decreases , (ii ) Th

e non-contiguou s reading s hav e relativel y

muchhigh er percentage s of thei r frequenc y distribution s great e r tha n5 % opacit

y tha nd o contiguou s readings . Thi s i s particularl y

tru e fo r th e highes t 2 an

d4 non contiguou s readings , (iii ) Inmos t case s a s th e range of mea

ntru e opacit

y increases , th

e percentage s give

ninTabl e 1 de creas e (thi s tren

di s mor e noticeabl e inTabl e A-3) . (iv ) Ingeneral , th e percentage s greater tha n5 % ar e smaller for blac ksmoke tha nfo r whit e smoke , (v ) Fo r blac ksmoke , th

e percentage s fo

r th e 3 - o r 4 - minut e contiguou s averagin g time s are (a ) about th e sam e a s for th

e 6-minut e averagin g tim e an d (b ) relativel y

muchsmaller tha

nfo r th e 30-secon

d averagin

g time . Fo

r whit e smoke , th

e result s ar e
no t a s clear-cut but i t doe s appear tha t th e 3 - o r

— Appendi xTabl e A- 3 give s th e sam e result s fo

r mea ndeviation s greater tha n0 % opacity .P.1 2

4-mihut e averaging tim e doe s (a ) abou t a s wel l a s the 6-minut e averaging time an d (b ) somewha t bette r than the 30-secon

d averaging time
. (vi ) Fo r th e stea

mstation , th e averag e o f two observer s usuall yha s slightl ysmalle r percentage s greate r than 5 % opacit ythan th e corresponding percentage s base d

o n on e observer
. B . Frequenc yDistributions.o f Mea n Observe d Opacit y RT I compute d frequencydistribution s o f mea n observe d opacit yfo r variou s range s o f mea n tru e opacit yan d Appendi x B present s a detaile d

summaryo f thes e frequenc ydistribution s fo r mea n tru e opacit yles s tha n 20 % (Tabl e B-1 ) an

d mea n tru e opacit yles s than 10 % (Tabl e B-2)
. I n addition , Tabl e 2 presents)th e percen t o f th e frequenc ydistributio n o f

mea n observe d opacit ygreate r than 10 % an d 20 % whe n mean.tru e opacit yi s les s than 10 % an

d 20% , respectively
. Thus , Tabl e 2 indicates , fo r th e variou s averaging times , th e percen t o f th e time tha t a n observe r woul d indicat e opacit yt o b e greate r than 10 % (or 20% ) when , i n fact , mea n tru e opacit ywa s les s tha n 10 % (or 20%)
. Tabl e 2 indicate s th e following results :

(i ) I n general , th e percentage s in-th e tabl e decreas e wit hincreasing averaging time , (ii ) Th e percentage s fo r th e non-contiguou s reading s ar e
muc hhighe r than fo r the contiguou s readings , (iii ) Th e percentage s fo r mea n tru e opacit y<10 % ar e muc h large r tha

n fo r mea n tru e opacit y<20%
. (iv ) Th e stea

mstatio n ha s lowe r percentage s than the smok e generator .Tabl e 2 . Percent o f Frequenc y Distributio

no f Mea nObserve

dOpacity

£10 % an

d20 % WhenMeanTrue Opacit y <10 % an

d20% , 2 / Respectively ; B

y Averagin

g Time , Stationan dSmoke Type Smoke Generator , Blac k Smoke

MeanTrue Opacit y (% ) <1 0 <2 0

<1 0 <2 0

<1 0 <2 0

<1 0 <2 0 MeanObserved

Opacity (% ) U O £2 0

£1 0 £2 0

£1 0 £2 0

£1 0 £2 0 3 0 sec .

% 52. 2 12. 4

• 41. 4 9. 3

19. 8 2. 0

14. 3

. 6 1 min .

% 51. 6 7. 0

39. 7 7. 5

13. 2 1. 3

9. 4

. 2 Contiguou s Reading s Averagin

g Tim e 2 min . 3 min . 4 min . 5 min . 6 min . % % % % % 39. 2 7. 1

37. 0 4. 2

16. 7 0. 0 Riverben

d 14. 4 0. 0 34.4 *

9. 9

43. 0 8. 7 2. 2 3. 3 2. 2 Non-Contiguou s Reading s Highes t 2
44. 8
Smoke Generator , Whit e Smoke 46. 0 43. 1 14.0 * 9. 5 5. 5 3. 0 30. 3 Riverben

dStea m Station , Whit e Smoke 15. 0 0. 0
Stea m 11. 7 0. 0 22.5 * 17.5 * 15.0 *

0. 0 0. 0 0. 0 63.6 * 18. 3 Averaging Tim e Highes t Highes t 4 8
28. 3

81.8 * 26. 8

35.3 * 10. 9 13. 8

20. 6

36.8 * 7. 8 Station , Whit e Smoke , Averag e o f Tw o Observer s 15. 0 11. 7 8. 3 0. 0 0. 0 0. 0 • Highes t 1 2
16. 6

48.0 * 20. 7

27.5 * 0. 0

— Tru e opacity

measuredb

y a transmissometer . 2 /

— Non-Contiguou s Highes t 2 an dContiguou s reading s define di nTabl e 1 . * = » Sampl e siz e between2 0 an d5 0 observations .

— = Sampl e siz e les s tha n2 0 observations .

### 1 0 ?.1 4

(v ) I t i s difficul t t o drawgenera l conclusion s regard

ing th e relativ e size s o f th e percentage s fo r th e variou s contiguou s averaging times
. However , ex cep t fo r th e whit e smok e a t th e smok e generator , 3

-
o r 4-minut e averaging time s d o abou t a s wel l a s 6

- minut e averaging times
. (vi ) A s wa s th e cas e fo r th e mea n deviation s i n A , th e averag e o f two observer s a t th e stea mstatio n ha s somewha t smalle r percentage s tha n th e corresponding percentage s base d o n on e observer
. C . Estimate s o f th e Bia s o f A n Observer' s Reading s Tabl e 3 present s estimate s o f th e bia s o f a n observe r b yaveraging time , station , smok e typ e an d rang e o f mea n tru e opacity
. Thes e esti

mate d biase s wer e compute d b yaveraging mea n deviation s ove r al l run s
and observers
. Th e tabl e indicates :

(i ) A s show

n i n [1] , th e estimate d bia s o f a n observer' s reading s becom e increasingl ynegativ e a s mea n tru e opacit yincreases , (ii ) A s woul d b e expected , th e lengt ho f th e contiguou s averaging time ha s littl e effec t o n th e estimate d .bia s o f a n observer
. Thi s i s partiall ydu e t o th e fac t tha t i n th e presen t cas e bia s fo r averaging time T i s define d as : Observe r Mea n (fo r averaging time T ) - Mea n Tru e Opacit y(for averaging time T)
. Thus , th e valu e o f mea n tru e opacit ychange s wit haveraging time
. I f o n th e othe r hand mea n tru e opacit ywer e define d fo r eac hru n fo r some fixe d time perio d (sa yTabl e 3 . 1 / 2 / Estimate s o f th

e Bia s o f a

nObserver

— ; B y Averagin

g Time , Station , Smok e Typ e an dMeanTrue Opacity —



### Mean True Opacit y(Z ) 0-1 0 10-2 0 20-3 0 30-4 0 £4 0 Overall- ' 3 0 sec .

X 

### 1. 0 -1. 0 -4. 0 -7. 7 -16. 4 1 min
.

X 

### 1. 0 -1. 1 -3. 4 -8. 6 Contiguou s Read i Smoke ng s Averagin

g Tim e 2 min
. 3 min
. 4 min
. X X

X



### . 2

- . 4 -4. 4 -7. 6 1. 1

-1. 5 -2. 9 -8. 7 1. 9

-1. 6 -2. 2 Generato r
5 min
. X 

### -1. 2 -2. 3 , Black Smoke
6 min
. X 

### -1. 6 -2. 0 No Highes t 2 2. 3 -1. 1

- . 7 .0 5 n-Contiguou s Read ! Averagin

g Tim e Highes t Highes t 4 8 1. 5 -1. 2 -1. 2

- .4 9 . 7

-1. 4 -4. 0 -1.2 6 ng s

Highes t 1 2

. 1 -2. 4 -6. 5 -1.7 8
0-1 0 10-2 0 20-3 0 30-4 0 £4 0 .rai l 1. 2

- . 3 -5. 1 -9. 6 . 9

- . 5 -5. 2 -8. 5 . 9

- . 7 -4. 7 -8. 5 1. 5

- . 8 -5. 8 -9. 1 Smoke

1. 2

- . 5 -4. 4 Generator ,

1. 1

- . 9 -4. 2 -8. 1 ^ Whit e I



### - . 2

- . 5 -4. 6 -8. 2 >mok

e 5. 2 2. 4 -1. 3 -7. 0 .4 7 2. 8 2. 4 -3. 6 -5. 6 .0 0 2. 6 1. 6 -5. 2 -4. 9

- .6 9 1. 3

. 9 -5. 4 -5. 7

- .9 5
0-1 0 10-2 0 20-3 0 30-4 0 >4 0 Overal l 1. 7

-2. 2 -2. 6 -6. 7 -8. 2 1. 6

-2. 2 -2. 8 -6. 8 -7. 2 1. 7

-2. 7 -2. 7 -7. 2

. 

### Riverben

d Stea mStation , Whit e Smoke 1. 7 -2. 7 -3. 3 -6. 1 1. 7

-2. 7 -3. 5 -5. 5 1. 7

-2. 6 -3. 8 -5. 1 1. 7

-2. 7 -4. 3 -4. 9 3. 7

2. 3

. 5 -6. 5 -6. 2 .3 4 3. 1 1. 6 -5. 9 -6. 2 .2 2 3. 1

- . 2 -5. 8

- .0 3 2. 7

-1. 3

. . 

### -5. 4

- .3 5

— Estimate

dBia s = [Observer Mean- MeanTrue Opacity ] averagedove r al l run s an dobservers . 2 /

— Non-Contiguou s Highes t 2 an dContiguou s reading s definedi nTabl e 1 . 3 /

— Overal l = ove r al l level s of mea ntru e opacity .

— = Sampl e siz e les s tha n1 0 observations .

' r oP.1 6



### 1 2

6 minutes) , the n the estimate d bia s o f a n observe r woul d undoubtedl yvarywit haveraging time
. Th e poin t her e i s tha t the observer' s mea n fo r differen t aver aging time s i s no t bein g compare d t o th e same tru e opacit ymean . Instead , th e tru e mea n i s als o bein g allowe d t o varywit haveraging time
. (iii ) I n general , the non-contiguou s reading s hav e esti

mate d biase s whic har e les s negativ e tha n th e esti

mate d biase s fo r contiguou s readings
. I n addition ,
a s the averaging time o f non-contiguou s reading s in

crease s (e.g. , from2 t o 12) , th e estimate d biase s become mor e negative
. D . Estimate s o f the Standard Deviatio n o f An Observer' s Bia s Tabl e 4 present s estimate d standard deviation s (s.d. ) o f th e esti

mate d biase s give n i n Tabl e 3 b yaveraging time , station , smok e type , an d rang e o f mea n tru e opacity
. Thes e s.d. s wer e compute d a s th e s.d
. o f

mea n deviation s ove r al l run s an d observers
. Accordingly , th e s.d. s give n i n Tabl e 4 no t onl ycontai n contribution s fromobserve r measuremen t erro r bu t als o fromdifference s i n mea n deviation s betwee n observer s an d betwee n
runs . Appendi x C discusse s thes e differen t contribution s i n detai l an d Tabl e 5 present s estimate s o f observe r measuremen t erro r (se e E below)
. Tabl e 4 show s th e following :

(i ) I n general , the standard deviation s decreas e wit h increasing averaging time bu t the decreas e i s • relativel ysmall
. Thi s tend s t o indicat e tha t the differenc e i n mea n deviation s i s relativel ylarg e betwee n runs ; an

d therefore , longe r averaging time s

### I I I I I f 

### 1 / Tabl e 4 . Estimate s of th e Standar

dDeviationo f anObserver' s Bias — 2 / Mea nTrue Opacity

— 

### itrii i B y Averagin

g Time , Station , Smoke Typ e an d

Riverben

dStea m Station , Whit e Smoke , Averag e o f Tw o Observer s 0-1 0 10-2 0 20-3 0 30-4 0 £4 0 Overal l 2. 1

2. 8 5. 7 7. 0 5. 5 5. 1 1. 8

2. 8 6. 1 6. 5 3. 8 4. 9 1. 7

2. 0 6. 0 5. 4 4. 7 1. 7

1. 9 6. 2 5. 4 4. 6 1. 7

1. 9 5. 2 5. 4 4. 3 1. 7

1. 9 5. 6 5. 2 4. 3 -•— » .. .

1. 6 1. 9 5. 4 6. 3 4. 5 MeanTrue Opacity (% ) 0-1 0 10-2 0 20-3 0 30-4 0 £4 0 3 / Overall 3 0 sec .

X 2. 2 4. 4 6. 4 6. 5 4. 3 5. 8 1 min .

X 1. 8 4. 2 6. 1 6. 1
5. 6 Smoke Contiguou s Reading s Averagin

g Tim e 2 min. . 3 min . 4 min . % % % 2. 0 1. 6 1. 8 3. 4 4. 0 4. 2 6. 0 4. 4 3. 8 6. 2 5. 3
5. 3 4. 9 4. 9 Generato r
5 min . X
3. 6 3. 5

4. 5 , Blac kSmoke
6 min . X
3. 7 3. 1

4. 4 N

o Highes t 2
4. 9 5. 6 4. 8
6. 0 n-Contiguou s Read !

Averagin

g Tim e Highes t Highes t 4 8
4. 3 5. 1 5. 2
5. 6 3. 4

4. 6 6. 0
5. 1 ng s Highes t 1 2
3. 3 4. 0 6. 3
4. 7
0-1 0 10-2 0 20-3 0 30-4 0 £4 0 Overal l 3. 1

4. 6 6. 2 7. 4 5. 9 2. 9

4. 5 6. 0 7. 1 5. 5 2. 9

4. 2 6. 0 7. 1 5. 4 2. 7

3. 8 5. 2 7. 0 5. 3 Smoke

2. 3 3. 9 4. 5
4. 9 Generator ,

2. 5 4. 3 4. 4 6. 8 5. 0 Whit e Smoke

1. 8 4. 4 5. 1 6. 6 5. 0 4. 6

5. 0 7. 0 6. 6 6. 8 2. 4

4. 9 7. 0 6. 4 6. 3 1. 9

4. 2 6. 6 5. 5 5. 9 1. 9

4. 4 5. 8 5. 4 5. 4
0-1 0 10-2 0 20-3 0 30-4 0 £4 0 Overal l 2. 7

4. 0 6. 8 7. 5 7. 0 5. 7 2. 3

4. 0 . 7. 0 7. 0 5. 6 5. 5 2. 3

3. 3 7. 0 5. 8 5. 3 Riverben

dStea m Station , Whit e Smoke 2. 3 3. 2 7. 3 5. 8 5. 1 2. 2

3. 2 6. 3 5. 8 4. 9 2. 2

3. 1 6. 6 5. 6 4. 9 2. 1

3. 1 6. 4

5. 0 2. 9

4. 7

7. 0 2. 8

4. 6 6. 0 6. 3 3. 0

4. 0 4. 3 5. 5 2. 8

3. 4 4. 2 5. 2

— The standar

ddeviatio

ngiveni s th

e standar

ddeviatio

no f th

e estimatedbiase s giveni nTabl e 3 and , therefore , thi s standar

ddeviatio

ncontain s contribution s fro m difference s betweenrun s an dobserver s (se e Appendi xC) . 2 /

— Non-Contiguou s Highes t 2 an dContiguou s reading s definedi nTabl e 1 . 3 /

— Overal l » Ove r al l level s o f mea ntru e opacity .

— = Sampl e siz e les s tha n1 5 observations .P.1 8



### 1 4

withi na ru

nd o not appreciably

reduc e th

e overal l s.d . (i nfact , thi s conclusio ni s show

nt o be th e
cas e inAppendi xC) . (ii ) Th

e non-contiguou s an dcontiguou s reading s hav e s.d. s whichar e about th

e sam e order of magnitude , (iii ) I t i s obviou s that a s th e range of mea

ntru e opacit

y increase s so doe s th e magnitude of th

e s.d.s . Thus , th e s.d. s whenmeantru e opacit

y i s 20-30 % are larger tha nwhe nmeantru

e opacit

y i s 0-10% . (iv ) As woul dbe expected , th e s.d. s fo

r th e average of tw o observer s ar e somewha t les s tha nth e s.d. s base

d
o nonly one observer . E . Estimate s o f A nObserver' s Measurement Erro r Tabl e 5 present s estimate s o f observe r measurement erro r fo r th e con tiguou s reading s b

y 4 averagin

g times , station , smok e typ e an dfo r mean tru e opacit

y greater tha

n10% . Th

e detail s of ho

w thes e estimate s wer e obtaine dar e give

ninAppendi xC . Inbrief , th e estimate s give

ninTabl e 5
ar e th e s.d . of a

nobserver' s mea

ndeviation s inrepeate dmeasurement s durin g th e sam e run . Tha t is , th e contribution s t

o th e s.d. s give

nin Tabl e 4 fro

m difference s betweenobserver s an dbetwee

nrun s hav

e beenre moved . A s woul db

e expected , th

e estimat e give

ninTabl e 5 sho

w that a s averagin

g tim e increase s th

e measurement erro

r of a nobserver decreases . Thi s i s t

o be expected , sinc e th e s.d . of a

naverage base

do nn . observa tions wil l always be les s tha no r equa l t

o th e s.d . base

do na naverage
o f n

_observations , wher e n - > n„ .P.1 9



### 1 5

Tabl e 5 . Estimate s of th e Measurement Error — of a nObserver' s Deviation s 

### 2 / fo r Mea nTru

e Opacity

>10% ; B

y Averagin

g Time , Station , an dSmoke Type

—



### >1 0 »
MeanTrue Opacity 

### >1 0 Contiguou s Reading s Smok e Generator , Blac kSmok e Averagin

g Tim e 3 0 sec . 1 min . 3 min . 6 min . 4. 2 4. 1 2. 8 1. 9 Smok e Generator , Whit e Smok e 

### 3. 6 2. 6 2. 3 1. 8

>1 0 Riverben dStea m Station , Whit e Smok e 

### 3. 4 2. 9 1. 8 1. 3

1/

2 / Estimate

dMeasuremen t Error *• » Estimate

dstandar

ddeviatio

nof a n observer' s meandeviation s i nrepeate dmeasurement s durin g th e sam e run . Al l estimate s base do nsampl e size s greate r tha n50 . Appendi xC give s th e procedur e use

dt o estimat e th

e measuremen t error .P.2 0



### 1 6

4 . SUMMAR

Y

Th e present study , usin g qualifie

dobserve r visua l opacit y reading s collecte

db y procedure s set forthinEP A Referenc e Metho

d9 , examine

d th e effec t of utilizin g averagin

g time s of les s tha n6 minute s t

o deter mine th e opacit

y of smok

e plume s (wher

e a 6-minut e averagin g tim e • mean
of 2 4 contiguou s singl e 15-secon dopacit

y readings) . Inaddition , th e stud y als o examine

dth e effec t of determinin g opacit

y a s th e average o f non-contiguou s 15-secon dopacit

y readings . Th

e effec t of th

e variou s con tiguous an

dnon-contiguou s averagin g time s wa s assesse db y comparin

g ob server reading s wit htru e opactiy

reading s a s determine db y a nin-stack transmissometer . Th e dat a analyze

dwer e fro

m tw o fiel dtest s conducte din 197 3 a t th

e Nationa l Environmenta l Researc hCenter , Researc

hTriangl e Park , NorthCarolin

a usin g tw o smok e generator s with9 qualifie dobserver s an

d i n197 4 at th

e Riverben

dStea m Statio nnear Charlotte , NorthCarolin a wit h 4 qualifie

dobservers . Th

e analysi s o f th

e dat a wa s don

e separatel y

fo r blac k an

dwhit e smok

e plumes . The averagin g time s examine

dwer e 3 0 seconds , 1 minute , 2 minutes , ... , 6 minutes . To determine th

e effec t of th

e variou s averagin

g times , RT I compute d
severa l statistic s b y averagin

g tim e an dleve l of mea

ntru e opacity . Althoug hgenera l conclusion s ar e difficul t t o draw , a

nexaminatio

nof thes e statistic s indicate dthat inmos t case s a 3 - o r 4-mlnut e averagin g tim e determine s average opacit y (a ) about a s wel l a s a 6-minut e averag in g tim e an d(b ) better tha

na 30-secon

daveragin

g time . Inaddition , non-contiguou s averagin g time s appear t

o b e a relatively

poo r metho do f obtainin

g average opacity . Mor e specifically , th e statistic s compute db y RT I include

dth e—

—

»

_

* • «

following : 

## ( D

(11 ) 

### 1 7

th e percent of th

e frequenc

y distributio

nfo r mean deviation s (observe r mean- tru

e opacit

y mean ) great er tha n5 % opacit

y (denot e thi s statisti c b y A) ; th e percent of th

e frequenc

y distributio

no f mean P.2 1

-

observe dopacity

greater tha

n10 % (20% ) opacity when
meantru

e opacit

y i s les s tha

n10 % (20% ) (denot e thi s statisti c b

y B) ; (iii ) th

e estimate

dbia s of a

nobserver' s reading s (wher e bia s - observe r mean- tru e opacit

y mean) ; (iv ) th

e estimate

dstandar

ddeviatio

nof a nobserver' s bias ;
an d (v ) th e estimate

dmeasuremen t erro

r o f a nobserver . Examinatio

nof thes e statistic s indicate dth e following : (i ) Fo r contiguou s readings , a s averagin g tim e Increases : Statistic s A

an dB generally

decreas e (however , i nman

y case s statistic s A
an dB hav e about th

e sam e relativ

e magni tud e fo r a 3 - or 4-minut e averagin g tim e
a s the y d o for a 6-minut e averagin g time) ; there i s littl e effec t o nth e estimate

d bia s o f a

nobserver ; th e estimate

dstandar

ddeviatio

nof a n observer' s bia s decrease s slightly ; an d th e estimate

dmeasurement erro

r of a n observer always decreases , (ii ) Fo

r non-contiguou s reading s (particularly , th e aver -P.2 2



### 1 8

age of th

e highes t 2 an

d4 non-contiguou s readings ) statistic s A

an dB hav e relatively

muchlarger mag nitude s tha

nfo r contiguou s readings . Thes e relative ly large magnitude s fo r th e non-contiguou s reading s indicat e that thi s metho dof averagin

g observe r opacit y reading s woul dgiv e mea nobserve

dopacit

y great e r tha nmeantru

e opacit

y ina relativel y

-larg e number of
cases . Thus , average percent opacit y shoul dprobabl y
not b e obtaine

dinthi s manner . Th e estimate

dob server biase s fo

r th e non-contiguou s reading s ar e les s negativ e tha nfo r th e contiguou s reading s whil e esti matedstandar

ddeviation s of thes e biase s are approxi matel y th e sam e a s fo r th e contiguou s readings , (iii ) Ingeneral , fo r th e contiguou s readings , th e follow in g statistic s base

do nth e average of tw

o observer s hav e somewha t smaller magnitude s tha nthos e base

do n
one observer :
A , B an dth e estimate

ds.d . o f a

nob server' s bia s (Note , measurement erro r wa s
not estimate

dbase do nth e average of tw

o observers) , (iv ) Ingeneral , a s th e leve l o f meantru e opacity

in creases : Statistic s A

an dB decrease ; th e estimate

dbia s of a

nobserver be come s mor e negative ; th e estimate

dstandar

ddeviatio

nof

### 1 9

anobserver' s bia s increases ; an d th e measurement erro

r of a nobserve r increases . Th e fac t tha t th

e abov e statistic s var

y wit hleve l

o f meantru

e opacity , i s th

e reaso nth e table s pre sente db y RT I inthi s repor t ar e givenfo r different
meantru

e opacity

levels . Finall y i t shoul dbe note

dthat i ncarryin

g out th

e present study , RT I foun

dtha t th

e sampl e size s (numbe r o f means ) availabl e fo r (a ) th

e contiguou s averagin g time s of 4 , 5 an

d6 minute s an

d(b ) th

e non-con tiguou s averagin

g - times , wer e severel y limite d(see , fo

r example , Tabl e 1) . Thus , man

y o f th e statistic s compute dfo r thes e averagin

g time s
wer e basedo

ninsufficient data . Accordingly , i f accurat e estimate s of al l th e statistic s presente dinthi s repor t ar e desired , fo r thes e aver agin g time s the

nadditiona l dat a shoul dbe examined . I naddition , th e
current dat a di dno t allo w a direc t investigatio no f stat e opacity

regu lation s suc

ha s "opacit

y canno t excee

d20 % fo

r mor e tha

n3 minute s a

n hour. " T

o accuratel y

asses s thi s regulatio nwoul drequir e dat a o n singl e minut e opacit y average s ove r on

e hou r periods . I f thi s type of dat a wer e availabl e the nfrequenc

y distribution s o

f th e highes t 3 non contiguou s singl e minut e average s i na nhou r coul db

e examine

ddirectly .P.2 4



### 2 0

REFERENCE S
[1 ] Hammill , H . F. , R . E . Thomas , an dN . F . Swynnerton , "Evaluatio nan d Collaborativ

e Stud y of Metho

dfo r Visua l Determinatio no f Opacity o f Emission s fro

m Stationar

y Sources, " Environmenta l Monitorin g Series , EPA-650/4-75-009 , Januar y 1975 . [2 ] "EP

A Respons e t

o Reman dOrdere

db y U.S . Cour t o f Appeal s fo r th e Distric t o f Columbi a i nPortlan dCement Associatio nV . Ruckelshau s (48 6 F . 2d375), " EPA-450/2-74-023 , Novembe r 1974 . [3 ] Barr , Anthon

y J. , an dGoodnight , Jame s H. , A User s Guide t

o th e Statistica l Analysi s System , Department o f Statistics , NorthCarolin a Stat e University , Augus t 1972 . [4 ] Anderson , R . L . an dBancroft , T . A. , Statistica l Theor y i nResearch , Ne w York : McGraw-Hil l Boo kCo. , Inc. , 1952 .P.2 5



### Appendi xA

• Frequenc y

Distribution s o f Mea nDeviation sP.2 6

A- l Tabl e A- l FrequencyDistribution s o f Mea n Deviations —

(Over Al l Mean Tru e Opaciites ) for Contiguou s 2 / an d Non-Contiguou s Readings

—; B yAveragin

g 3 / Time , Station an

d Smok e Type —

Smok e Generator , Blac k Smoke , Contiguou s Reading s Mean Deviation % <-2 0 -2 0 t o -1 5 -1 5 t o -1 0 -1 0 t o - 5

- 5 t o 0 0 t o 5 5 t o 1 0 1 0 t o 1 5 Tota l Sampl e Siz e 3 0 sec .

% 

### 1. 0 2. 3 7. 1 14. 0 32. 6 35. 8 

### 6. 8

. 4 

### 10 0 159 6 1 min
.

%



### . 8 

### 2. 5 8. 5 13. 8 32. 3 37. 5 

### 4. 4

. 3 

### 10 0 79 8 Averaging Time 2 min
. % 

### 0. 0 2. 8 8. 5 13. 8 34. 1 37. 6 

### 3. 0

. 3 

### 10 0 39 9 3 min
.

% 

### 0. 0

. 8 

### 9. 8 15. 0 36. 1 36. 5 

### 1. 9 0. 0 10 0 26 6 4 min
.

% 

### 0. 0

. 8 12. 0 

### 9. 0 38. 3 39. 1



### . 8 

### 0. 0 10 0 13 3 5 min
.

% 

### 0. 0

. 8 10. 5 

### 9. 0 40. 6 38. 3



### . 8 

### 0. 0 10 0 13 3 6 min
.

% 

### 0. 0

. 8 10. 5 10. 5 42. 1 35. 3



### . 8 

### 0. 0 10 0 13 3

Smok e Generator , Whit e Smoke , Contiguou s Reading s <-2 0 -2 0 t o -1 5 -1 5 t o -1 0 -1 0 t o - 5

- 5 t o 0 0 t o 5 5 t o 1 0 1 0 t o 1 5 Tota l Sampl e Siz e 

### . 7



### 1. 2 5. 8 13. 5 29. 8 37. 3 10. 1 

### 1. 6 10 0 202 9 

### . 6



### 1. 0 5. 7 13. 1 32. 7 37. 9 

### 8. 5

. 5 

### 10 0 101 5 

### . 6

. 8 

### 5. 5 13. 8 34. 8 36. 4 

### 7. 9

. 2 

### 10 0 50 8 . 6 

### 0. 0 7. 4 13. 6 34. 2 36. 0 

### 8. 0

. 3 

### 10 0 33 9 . 6 

### 0. 0 4. 7 14. 2 36. 1 35. 5 

### 8. 9 0. 0 10 0 16 9 . 6 

### 0. 0 3. 5 15. 9 39. 4 32. 9 

### 7. 6 0. 0 10 0 17 0 . 6 

### 0. 0 4. 1 15. 3 41. 2 31. 8 

### 7. 1 0. 0 10 0 17 0P.2 7



### A- 2 Tabl e A- l Continue d

Riverben

d Stea m Mea n Deviatio n % <-2 0 -2 0 t o -1 5 -1 5 t o -1 0 -1 0 t o - 5

- 5 t o 0 0 t o 5 5 t o 1 0
. 1 0 t o 1 5 Tota l Sampl e Siz e 3 0 sec .

%



### . 3 

### 1. 9 5. 2 14. 7 28. 3 40. 1 

### 7. 3 2. 2 10 0 115 2 Station ,

1 min
. % 

### 0. 0 1. 9 5. 6 14. 2 28. 8 41. 8 

### 6. 4 1. 2 10 0 57 6 Whit e Smoke , Contiguou s

Averaging Time 2 min
. % 

### 0. 0 1. 7 4. 9 14. 9 30. 6 40. 6 

### 6. 3 1. 0 10 0 28 8 3 min
.

% 

### 0. 0 1. 0 7. 8 14. 1 29. 2 41. 7 

### 5. 2 1. 0 10 0 19 2 4 min
.

% 

### 0. 0 1. 0 5. 2 13. 6 31. 3 42. 7 

### 5. 2 1. 0 10 0 9 6 Readin

g
5 min
. % 

### 0. 0 2. 1 4. 2 11. 4 30. 2 46. 9 

### 4. 2 1. 0 10 0 9 6 LS . 6 min
. % 

### 0. 0 1. 0 7. 3 10. 4 32. 3 43. 8 

### 4. 2 1. 0 10 0 9 6

Riverben

d Stea mStation , Whit e Smoke , Averag e o f Two Observers , Contiguou s Reading s <-2 0 -2 0 t o -1 5 -1 5 t o -1 0 -1 0 t o - 5

- 5 t o 0 0 t o 5 5 t o 1 0 1 0 t o 1 5 Tota l Sampl e Siz e 

### 0. 1

1. 7 4. 8 11. 9 34. 3 40. 9 

### 5. 3 1. 0 10 0 172 8 

### 0. 0

2. 0 4. 9 12. 2 33. 8 41. 5 

### 5. 3 0. 3 10 0 86 4 0. 0 0. 9 6. 5 10. 2 36. 1 41. 4 

### 4. 4 0. 5 10 0 43 2 0. 0 0. 0 6. 9 11. 5 34. 0 42. 4 

### 4. 9 0. 3 10 0 28 8 0. 0 0. 0 5. 5 13. 2 35. 4 41. 7 

### 4. 2 0. 0 10 0 14 4 0. 0 0. 0 6. 2 10. 4 36. 8 42. 4 

### 4. 2 0. 0 10 0 14 4 0. 0 0. 0 5. 5 11. 8 36. 1 41. 7 

### 4. 9 0. 0 10 0 14 4P.2 8

A- 3 Tabl e A- l Continue d

Non-Contiguou s Reading s Smok e Generator , Blac k Smok e
Mea n • Deviatio n
<-2 0 -2 0 t o -1 5 -1 5 c o -1 0 -1 0 t o - 5

- 5 t o 0 0 t o 5 5 t o 1 0 1 0 t o 1 5
Tota l Sampl e Siz e lighes t

2 

# I 0

. 9 4. 7 11. 7 22. 7 36. 7 19. 5 3. 9 10 0 12 8 Averagin g Tim e Highes t 4 

## 1 0 3. 1 3. 1 14. 1 21. 9 43. 7 13. 3

. 9 10 0 12 8 Highes t

8 

### Z 0

. 8 7. 0 13. 3 28. 1 43. 8 6. 3

. 8 10 0 12 8 Highes t

1 2 

# 1 0

. 8 5. 5 18. 0 32. 0 40. 6 3. 1 0 10 0 12 8 Smok e Generator , Whit e Smok e

Mea n Deviatio n
<-2 0 -2 0 t o -1 5 -1 5 t o -1 0 -1 0 t o - 5

- 5 t o 0 0 t o 5 5 t o 1 0 1 0 t o 1 5
Tota l Sampl e Siz e lighes t

2 

# I

. 6

. 6 5. 6 7. 5 21. 3 37. 5 18. 8 8. 1 10 0 16 0 Averagin g Highes t 4 

# I 0. 0 2. 5 4. 4 9. 4 23. 8 36. 9 18. 1 .5. 0 10 0 16 0 Tim e Highes t 8 

# I 0. 0 2. 5 5. 0 11. 9 26. 9 35. 0 17. 5 1. 3 10 0 16 0 Highes t

1 2 

# I 0. 0 0. 0 6. 3 15. 6 26. 9 36. 3 13. 8 1. 3 10 0 16 0

Riverben d SteamStation , Whit e Smok e <-2 0 -2 0 t o -1 5 -1 5 t o -1 0 -1 0 t o - 5

- 5 t o 0 0 t o 5 5 t o 1 0 1 0 t o 1 5
Tota l Sampl e Siz e 1. 0

1. 0 6. 3 8. 3 26. 0 32. 3 19. 8 5. 2 10 0 9 6 0. 0

1. 0 7. 3 8. 3 25. 0 36. 5 18. 8 3. 2 10 0 9 6 0. 0

0. 0 6. 3 11. 5 28. 1 42. 7 9. 4 2. 1 10 0 9 6 0. 0 0. 0 3. 1 14. 6 29. 2 44. 8 6. 3 2. 1 10 0 9 6

1 / 2 / —Mea n Deviation s « observe r mea n - tru e opacit ymea n

3 / Contiguou s 3 0 sec . • mea n o f 2 contiguou s singl e 15-second readings
. Non-Contiguou s Highes t 2 = mea n o f highes t 2 non-contiguou s singl e 15-second reading s i n a 6-minut e observatio n perio d (i.e. , i n a run)
.

—Tabl e A- 2 give s th e frequenc ydistribution s byleve l o f mea n tru e opacity
.P.2 9



### A- 4 1 / Tabl e A- 2 FrequencyDistribution s o f Mean Deviations

—fo r Contiguou s 2 / Readings

—

; B yAveraging Time , Station , Smok e Typ e an d Mea n Tru e Opacity

Smoke Generator , Blac k Smoke , Contiguou s Reading s

Mea n Tru e Opacity° 0 t o 10 % Mean Deviatio n % <-2 0 -2 0 t o -1 0 -1 0 t o 0 0 t o 5 5 t o 1 0 1 0 t o 1 5 Tota l Sampl e Siz e 3 0 sec .

% 

### 0. 0 0. 0 21. 1 73. 0 

### 5. 9 0. 0 10 0 27 0 1 min
.

% 

### 0. 0 0. 0 20. 5 78. 7 

### 0. 8 0. 0 10 0 12 2 Averaging Time 2 min
. % 

### 0. 0 0. 0 31. 1 68. 9 

### 0. 0 0. 0 10 0 7 4 3 min
. 4 min
. %
. % 

### 0. 0 0. 0 40. 6 59. 4 

### 0. 0 0. 0 10 0
. 

### 3 2 5 min
.

%

- 6 min
.

%

-

<-2 0 -2 0 t o -1 0 -1 0 t o 0 0 t o 5 5 t o 1 0 1 0 t o 1 5 Tota l Sampl e Siz e 

### 0. 0

2. 6 52. 9 35. 3 

### 8. 6 0. 6 10 0 73 0 Mea n Tru e Opacity



### 0. 0 2. 7 54. 9 35. 8 

### 6. 6 0. 0 10 0 36 6 0. 0 0. 0 53. 3 40. 6 

### 6. 1 0. 0 10 0 16 5 = 1 0 t o 

### 0. 0 6. 0 47. 7 43. 6 

### 2. 7 0. 0 10 0 14 9 20 % 0. 0 10. 7 49. 3 38. 7 

### 1. 3 0. 0 10 0 7 5 

### 0. 0 6. 6 46. 1 46. 2 

### 1. 1 0. 0 10 0 9 1 

### 0. 0 7. 3 50. 0 41. 5 

### 1. 2 0. 0 10 0 8 2

<-2 0 -2 0 t o -1 0 -1 0 t o 0 0 t o 5 5 t o 1 0 1 0 t o 1 5 Tota l Sampl e Siz e 

### 3. 2

10. 5 56. 4 23. 1 

### 6. 0 0. 8 10 0 38 1 Mean Tru e



### 2. 3 11. 2 53. 5 •27. 9 

### 4. 2 0. 9 10 0 21 5 Opacity 

### 0. 0 17. 0 56. 0 24. 0 

### 2. 0 1. 0 10 0 10 0 » 2 0 t o 

### 0. 0 4. 0 70. 0 24. 0 

### 2. 0 0. 0 10 0 5 0 

### 30 % 0. 0 3. 0 63. 7 33. 3 

### 0. 0 0. 0 10 0 3 3 

### 0. 0 3. 0 69. 7 27. 3 

### 0. 0 0. 0 10 0 3 3 

### 0. 0 2. 9 70. 6 26. 5 

### 0. 0 0. 0 10 0 3 4A- 5 Tabl e A- 2 Continue d P.3 0

Smok e Generator , Blac k Smoke , Contiguou s Reading s

Mea n Deviatio n % <-2 0 -2 0 t o -1 0 -1 0 t o 0 0 t o 5 5 t o 1 0 1 0 t o 1 5
Tota l Sampl e Siz e 3 0 sec .

%



### . 5 39. 1 42. 6 14. 2 

### 3. 6 0. 0 10 0 19 7 Mea n Tru e

1 min
. % 

### 0. 0 53. 5 31. 4 13. 9 

### 1. 2 0. 0 10 0 8 6 Opacit y = 3 0 t o 40 %

Averagin g Tim e 2 min
. % 

### 0. 0 46. 7 40. 0 13. 3 

### 0. 0 0. 0 10 0 6 0 3 min
. % 

### 0. 0 48. 6 48. 6 

### 2. 8 0. 0 0. 0 10 0 3 5 4 min
. %

- 5 min
.

%

- 6 min
.

%

-

Smok e Generator , Whit e Smoke , Contiguou s Reading s 0 t o 10 % <-2 0 -2 0 t o -1 0 -1 0 t o 0 0 t o 5 5 t o 1 0 1 0 t o 1 5
Tota l Sampl e Siz e 

### 0. 0

0. 0 22. 9 64. 0 11. 3 

### 1. 8 10 0 61 1 0. 0

0. 0 28.9

- 62. 1 

### 8. 7

. 3 

### 10 0 34 3 0. 0 0. 0 33. 7 50. 2 

### 8. 1 0. 0 10 0 18 4 0. 0 0. 0 24. 0 64. 0 12. 0 

### 0. 0 10 0 10 0 0. 0 0. 0 22. 0 74. 0 

### 4. 0 0. 0 10 0 5 0 

### 0. 0 0. 0 29. 4 66. 7 

### 3. 9 0. 0 10 0 5 1 

### 0. 0 0. 0 53. 5 46. 5 

### 0. 0 0. 0 10 0 4 3

<-2 0 -2 0 t o -1 0 -1 0 t o 0 0 t o 5 5 t o 1 0 1 0 t o 1 5
Tota l Sampl e Siz e 

### 0. 0

0. 5 52. 7 30. 9 13. 3 

### 2. 6 10 0 85 4 Mea n Tru e



### 0. 0 0. 0 56. 0 30. 8 12. 2 

### 1. 0 10 0 39 0 Opacit y 

### 0. 0 0. 0 60. 9 27. 4 11. 2



### . 5 

### 10 0 17 9 = 1 0 t o 

### 0. 0 0. 0 59. 5 30. 7 

### 9. 2

• 6
. 

### 10 0 15 3 20 % 0. 0 0. 0 61. 8 22. 4 15. 8 

### 0. 0 10 0 7 6 

### 0. 0 0. 0 65. 8 19. 7 14. 5 

### 0. 0 10 0

. 7 6 

### 0. 0 0. 0 56. 5 30. 4 13. 1 

### 0. 0 10 0 9 2P.3 1

A- 6 Tabl e A- 2 Continued

Smok e Generator , Whit e Smoke , Contiguou s Reading s

Mean Tru e Opacity- 2 0 t o 30 % Mean Deviatio n % <-2 0 -2 0 t o -1 0 -1 0 t o 0 0 t o 5 5 t o 1 0 1 0 t o 1 5 Tota l Sampl e Siz e 3 0 sec .

% 

### 0. 5 21. 2 51. 8 21. 2 

### 5. 3 0. 0 10 0 37 8 1 min
.

% 

### 0. 5 20. 8 53. 8 20. 8 

### 4. 1 0. 0 10 0 19 7 Averaging Tim e 2 min
. % 

### 0. 0 19. 6 52. 9 22. 6 

### 4. 9 0. 0 10 0 10 2 3 min
.

% 

### 0. 0 28. 3 55. 0 15. 0 

### 1. 7 0. 0 10 0 6 0 4 min
.

% 

### 0. 0 14. 7 64. 7 17. 7 

### 2. 9 0. 0 10 0 3 4 5 min
.

% 

### 0. 0 7. 7 69. 2 23. 1 

### 0. 0 0. 0 10 0 2 6 6 mi n

%

-

<-2 0 -2 0 t o -1 0 -1 0 t o 0 0 t o 5 5 t o 1 0 1 0 t o 1 5 Tota l Sampl e Siz e 

### 7. 0

31. 2 49. 4 11. 3 

### 1. 1 0. 0 10 0 18 6 Mea n Tru e



### 5. 9 31. 8 49. 4 12. 9 

### 0. 0 0. 0 10 0 8 5 Opacity 

### 7. 0 27. 9 51. 2 13. 9 

### 0. 0 0. 0 10 0 4 3 - 3 0 t o 40 % 

### 7. 7 30. 7 53. 9 

### 7. 7 0. 0 0. 0 10 0 2 6

-

Riverben

d Stea mStation , Whit e Smoke , Contiguou s Reading s
<-2 0 -2 0 t o -1 0 -1 0 t o 0 0 t o 5 5 t o 1 0 1 0 t o 1 5 Tota l Sampl e Siz e 

### 0. 0

0. 0 17. 0 71. 3 

### 9. 8 1. 9 10 0 46 0 Mea n Tru e



### 0. 0 0. 0 14. 9 77. 2 

### 7. 9 0. 0 10 0 22 8 Opacity 

### 0. 0 0. 0 16. 7 72. 5 10. 8 

### 0. 0 10 0 12 0 » 0 t o 

### 0. 0 0. 0 16. 3 72. 5 11.2 ' 

### 0. 0 10 0 8 0 

### 10 % 0. 0 0. 0 12. 5 75. 0 12. 5 

### 0. 0 10 0 4 0 

### 0. 0 0. 0 10. 0 80, 0 10. 0 

### 0. 0 10 0 4 0 

### 0. 0 0. 0 15. 0 75. 0 10. 0 

### 0. 0 10 0 4 0P.3 2



### A- 7 Tabl e A- 2 Continued

Riverben

d Stea mStation , Whit e Smoke , Contiguou s Reading s Mean Tru e Opacity= 1 0 t o 20 % Mean Deviatio n % <-2 0 -2 0 t o -1 0 -1 0 t o 0 0 t o 5 5 t o 1 0 1 0 t o 1 5 Tota l Sampl e Siz e 3 0 sec .

% 

### 0. 0 0. 3 69. 2 25. 3 

### 4. 6

. 6 

### 10 0 30 8 1 min
.

% 

### 0. 0 0. 0 69. 2 25. 0 

### 5. 1

. 7 

### 10 0 15 6 Averagin

g Time 2 min
. % 

### 0. 0 0. 0 76. 4 23. 6 

### 0. 0 0. 0 10 0 7 2 3 min
. 4 min
. % % 0. 0 0. 0 0. 0 0. 0 77. 1 75. 0 22. 9 25. 0 0. 0 0. 0 0. 0 0. 0 10 0 10 0 4 8 2 4 5 min
.

% 

### 0. 0 0. 0 70. 8 29. 2 

### 0. 0 0. 0 10 0 2 4 6 min
. % 

### 0. 0 0. 0 75. 0 25. 0 

### 0. 0 0. 0 10 0 2 4

<-2 0 r-2 0 t o -1 0 -1 0 t o 0 0 t o 5 5 t o 1 0 1 0 t o 1 5 Tota l Sampl e Siz e 

### 0. 0

10. 9 59. 4 18. 9 

### 6. 1 4. 7 10 0 21 2 Mea n Tru e



### 0. 0 12. 5 58. 0 18. 8 

### 5. 4 5. 3 10 0 11 2 Opacity 

### 0. 0 11. 5 57. 7 19. 2 

### 5. 8 5. 8 10 0 5 2 = » 2 0 t o 30 % 

### 0. 0 17. 9 57. 1 17. 9 

### 0. 0 7. 1 10 0 2 8 - -

Mean Tru e Opacity= 3 0 t o 40 % <-2 0 -2 0 t o -1 0 -1 0 t o 0 0 t o 5 5 t o 1 0 1 0 t o 1 5 Tota l Sampl e Siz e 

### 1. 5

33. 3 44. 0 11. 4 

### 6. 8 3. 0 10 0 13 2 0. 0

35. 9 50. 0 

### 6. 3 7. 8 0. 0 10 0 6 4 

### 0. 0 32. 5 60. 0 

### 2. 5 5. 0 0. 0 10 0 4 0 

### 0. 0 37. 5 ' 50. 0 

### 9. 4 3. 1 0.0
. 

### 10 0 3 2

-P.3 3

A- 8 Tabl e A- 2 Continue d

Riverben

dStea m Station , Whit e Smoke , Averag e o f Tw o Observers , Contiguou s Reading s

Mea nTru e Opacit y

= 0 t o 10 % Mea n Deviatio n % <-2 0 -2 0 t o -1 0 -1 0 t o 0 0 t o 5 5 t o 1 0 1 0 t o 1 5
Tota l Sampl e Siz e 3 0 sec .

% 

### 0. 0 0. 0 13. 2 79. 4 

### 6. 4 1. 0 10 0 69 0 1 min .

% 

### 0. 0 0. 0 12. 3 82. 7 

### 5. 0 0. 0 10 0 34 2 Averaging Tim e 2 min . % 

### 0. 0 0. 0 10. 6 84. 4 

### 5. 0 0. 0 10 0 18 0 3 min .

% 

### 0. 0 0. 0 6. 7 86. 6 

### 6. 7 0. 0 10 0 12 0 4 min .

% 

### 0. 0 0. 0 8. 3 85. 0 

### 6. 7 0. 0 10 0 6 0 5 min .

% 

### 0. 0 0. 0 6. 7 86. 6 

### 6. 7 0. 0 10 0 6 0 6 min .

% 

### 0. 0 0. 0 6. 7 86. 6 

### 6. 7 0. 0 10 0 6 0

<-2 0 -2 0 t o -1 0 -1 0 t o 0 0 t o 5 5 t o 1 0 1 0 t o 1 5
Tota l Sampl e Siz e 

### 0. 0

0. 0 80. 7 17. 1 

### 2. 2 0. 0 10 0 46 2 Mea nTru e



### 0. 0 0. 0 81. 6 15. 8 

### 2. 2

. 4 10 0 23 4 Opacit y 

### 0. 0 0. 0 89. 8 10. 2 

### 0. 0 0. 0 10 9 10 8 » 1 0 t o 

### 0. 0 0. 0 91. 7 

### 8. 3 0. 0 0. 0 10 0 7 2 20 % 0. 0 0. 0 94. 4 

### 5. 6 0. 0 0. 0 10 0 3 6 0. 0 0. 0 94. 4 

### 5. 6 0. 0 0. 0 10 0 3 6 0. 0 0. 0 94. 4 

### 5. 6 0. 0 0. 0 10 0 3 6

<-2 0 -2 0 t o -1 0 -1 0 t o 0 0 t o 5 5 t o 1 0 1 0 t o 1 5
Tota l Sampl e Siz e 

### 0. 0

7. 2 63. 5 18. 3 

### 7. 9 3. 1 10 0 31 8 Mea nTru e



### 0. 0 10. 7 60. 7 16. 7 10. 7 

### 1. 2 10 0 16 8 Opacit y 

### 0. 0 10. 3 62. 8 12. 8 11. 5 

### 2. 6 10 0 7 8 - 20 % 

### 0. 0 11. 9 64. 3 11. 9 9.5 - 

### 2. 4 10 0 4 2 t o 30 % 

### 0. 0 8. 3 75. 0 

### 8. 4 8. 3 0. 0 10 0 2 4 0. 0 12. 5 70. 9 

### 8. 3 8. 3 0. 0 10 0 2 4 0. 0 6. 7 80. 0 

### 3. 3 10. 0 

### 0. 0 10 0 3 0P.3 4



### A- 9
Tabl e A- 2 Continue d

Riverben d Stea mStation , Whit e Smoke , Averag e o f Tw o Observers , Contiguou s Reading s

Mea n Tru e Opacit y= 3 0 t o 40 % Mea n Averagin g Tim e Deviatio n % <-2 0 -2 0 t o -1 0 -1 0 t o 0 0 t o 5 5 t o 1 0 1 0 t o 1 5
Tota l Sampl e Siz e 3 0 sec .

% 

### 0. 5 35. 8 47. 0 

### 9. 6 6. 6 0. 5 10 0 19 8 1 min
.

% 

### 0. 0 36. 5 45. 8 11. 5 

### 6. 2 0. 0 10 0 9 6 2 min
.

% 

### 0. 0 40. 0 51. 6 

### 6. 7 1. 7 0. 0 10 0 6 0 3 min
.

% 

### 0. 0 31. 2 56. 3 

### 8. 3 4. 2 0. 0 10 0 4 8 4 min
.

% 

### 0. 0 25. 0 54. 2 20. 8 

### 0. 0 0. 0 10 0 2 4 5 min
.

% 

### 0. 0 25. 0 54. 2 20. 8 

### 0. 0 0. 0 10 0 2 4 6 min
.

%

-

—Mea n Deviation s - observe r mea n - tru e opacit ymean . 2 / -<• Contiguou s 3 0 sec . = mea n o f 2 contiguou s singl e 15-secon d readings
.

- = » Sampl e siz e les s tha n 2 0 observations
.Appendi xTabl e A- 3 Percen t o f Frequenc yDistributio n fo r Mea n Deviations

—£ 0 Percen t Opacity ; B y 2 / Averagin g Time , Station , Smok e Typ e an d Mea n Tru e Opacity —

Mea n Tru e Opacit y(% ) 0-1 0 10-2 0 20-3 0 30-4 0 3 / Overall

3 0 sec . % 78. 9 45. 2 29. 9 17. 8 43. 0 1 min
.

% 79. 5 42. 4 33. 0 15. 1 42. 2 Smok e Contiguou s Reading s Averagin g Tim e 2 min
. 3 min
. 4 min
. X X X 68. 9 59.4 * 46. 7 46. 3 27. 0 26. 0 13. 3 2.8 *

• 40. 9 38. 4 40. 0 33.3 *
39. 9 Generato r

5 min
. %
47. 3 27.3 *
39. 1 , Blac k Smok e Non-Contiguou s Reading s

6 min
. %
42. 7 26.5 *
36. 1 Highes t

2
79. 3 44.7 *
60. 1 Averaging Tim e

Highes t Highes t 4 8
72. 4 45.5 *
57. 9 64. 9

43.5 * 35.0 * 50. 9 Highes t

1 2
59. 0 31.7 * 19.0 * 43. 7

0-1 0 10-2 0 20-3 0 30-4 0 Overal l 77. 1

46. 8 26. 5 12. 4 49. 0 71. 1

44. 0 24. 9 12. 9 46. 9 66. 3

39. 1 27. 5 13.9 * 44. 5 76. 0

40. 5 16. 7 7.7 * 44. 3 Smok e

78. 0 38. 2 20.6 * 44. 4 Generator ,

70. 6 34. 2 23.1 * 40. 5 Whit e Smok e

46.5 * 43. 5

38. 9 79. 0

44.8 * 17.4 * 64. 2 100.0 *

69. 6 35.0 * 60. 0 61. 9

23.8 * 53. 8 59. 7

21.8 * 51. 4 

## T

0-1 0 10-2 0 20-3 0 30-4 0 rai l 83. 0

30. 5 29. 7 21. 2 49. 6 85. 1

30. 8 29. 5 14. 1 49. 4 83. 3

23. 6 30. 8 7.5 * 47. 9 83. 7

22.9 * 25. 0 12.5 * 47. 9 Stea mStation ,

87.5 * 25.0 *

48. 9 90.0 *

29.2 *

52. 1 Whit e Smok e

85.0 * 25.0 *

49. 0 90.5 *

66.6 *

57. 3 88.3 *

63.4 *

58. 5 86.9 *

88.4 * 45.0 * 54. 2 87.5 *

37.
. 5 * 55.0 * 53. 2

0-1 0 10-2 0 20-3 0 30-4 0 Overal l 86. 8

19. 3 29. 3 16. 7 47. 2 87. 7

18. 4 28. 6 17. 7 47. 1 89. 4

10. 2 26. 9 8. 4 46. 3 93. 3

8. 3 23.8 * 12.5 * 47. 6 91. 7

5.6 * 16.7 * 20.8 * 45. 9 93. 3

5.6 * 16.6 * 20.8 * 46. 6 «_:*.:,.- i

93. 3 5.6 * 13.3 * 46. 6

Mea n Deviation s •

= Observe d mea n - tru e opacit ymean . No n Contiguou s Highes t 2 an d contiguou s reading s define d l n Tabl e A-l
. 1 / 

### If 3 /

—Overal l = ove r al l level s o f mea n tru e opacity
. * = Sampl e siz e betwee n 2 0 an d 5 0 observations
.

- = Sampl e siz e les s tha n 2 0 observations
.

c o O lP.3 6

Appendi x B Frequenc yDistribution s o f Mea n Observe d Opacit y fo r Mea n Tru e Opacit yLes s Tha n 2 0 Percen t an d Mea n Tru e Opacit yLes s Tha n 1 0 Percen tP.3 7

B- 1 Tabl e B- 1 FrequencyDistribution s o f Mean Observe d OpacityWhe n

Mean Tru e Opacity<20 % fo r Contiguou s an d Non-Contiguou s Readings

—

; B yAveragin

g Time , Station an

d Smok e Typ e

Smok e Generator , Blac k Smoke , Contiguou s Reading s Mean Observed Opacity 0 t o 5 5 t o 1 0 1 0 t o 1 5 .1 5 t o 2 0 2 0 t o 2 5 2 5 t o 3 0 3 0 t o 3 5 

### >3 5 Tota l Sampl e Siz e 3 0 sec .

% 

### 2. 3 20. 8 39. 1 25. 4 10. 8 

### 1. 6 0. 0 0. 0 10 0 100 0 1 min
.

% 

### 3. 3 23. 4 44. 5 21. 9 

### 6. 6

. 4 

### 0. 0 0. 0 10 0 48 8 Averagin

g Time 2 min
. %



### . 8 28. 5 44. 8 18. 8 

### 7. 1 0. 0 0. 0 0. 0 10 0 23 9 3 min
.

% 

### 2. 2 27. 1 44. 2 16. 6 

### 8. 8 1. 1 0. 0 0. 0 10 0 18 1 4 min
.

% 

### 6. 6 14. 3 60. 4 16. 5 

### 2. 2 0. 0 0. 0 0. 0 10 0 9 1 5 min
.

% 

### 5. 5 13. 2 59. 3 18. 7 

### 3. 3 0. 0 0. 0 0. 0 10 0 9 1 6 min
.

% 

### 2. 2 17. 7 56. 7 21. 1 

### 2. 2 0. 0 0. 0 0. 0 10 0 9 0

Smok e Generator , Whit e Smoke , Contiguou s Reading s 0 t o 5 5 t o 1 0 1 0 t o 1 5 1 5 t o 2 0 2 0 t o 2 5 2 5 t o 3 0 3 0 t o 3 5 

### >3 5 Tota l Sampl e Siz e 

### 2. 5

33. 2 38. 5 16. 4 

### 7. 5 1. 8 0. 0 0. 0 10 0 146 5 

### 3. 8

36. 6 38. 7 13. 4 

### 6. 4 1. 1 0. 0 0. 0 10 0 73 3 6. 1 39. 7 37. 7 12. 4 

### 3. 9

. 3 

### 0. 0 0. 0 10 0 36 3 7. 5 34. 4 39. 5 

### 9. 9 8. 3

. 4 

### 0. 0 0. 0 10 0 25 3 1. 6 42. 9 37. 3 

### 8. 7 9. 5 0. 0 0. 0 0. 0 10 0 12 6 . 8 48. 0 33. 1 12. 6 

### 5. 5 0. 0 0. 0 0. 0 10 0 12 7 . 7 45. 2 31. 1 20. 0 

### 3. 0 0. 0 0. 0 0. 0 10 0 13 5Tabl e B- 1 Continue d P.3 8

Riverben dStea

m Station , Whit e Smoke , Contiguou s Reading s Mean Observe d Opacit y 0 t o 5 5 t o 1 0 1 0 t o 1 5 1 5 t o 2 0 2 0 t o 2 5 2 5 t o 3 0 3 0 t o 3 5 

### >3 5
Tota l Sampl e Siz e 3 0 sec .

% 

### 2. 0 58. 1 26. 8 11. 1 

### 1. 8

. 1

. 1 0. 0 10 0 76 8 1 min .

% 

### 2. 9 62. 0 24. 2 

### 9. 6 1. 3 0. 0 0. 0 0. 0 10 0 38 4 Averaging Time 2 min . % 

### 4. 2 60. 9 27. 6 

### 7. 3 0. 0 0. 0 0. 0 0. 0 10 0 19 2 3 min .

% 

### 4. 7 62. 5 26. 6 

### 6. 2 0. 0 0. 0 0. 0 0. 0 , 

### 10 0 12 8 4 min .

% 

### 4. 7 56. 2 34. 4 

### 4. 7 0. 0 0. 0 0. 0 0. 0 10 0 6 4 5 min .

% 

### 4. 7 57. 8 29. 7 

### 7. 8 0. 0 0. 0 0. 0 0. 0 10 0 6 4 6 min .

% 

### 3. 1 64. 1 25. 0 

### 7. 8 0. 0 0. 0 0. 0 0. 0 10 0 6 4

Riverben dStea

m Station , Whit e Smoke , Averag e o f Two Observers , Contiguou s Reading s 0 t o 5 5 t o 1 0 1 0 to 1 5 1 5 to 2 0 2 0 to 2 5 2 5 t o 3 0 3 0 t o 3 5 

### >3 5
Tota l Sampl e Siz e 

### 3. 6

60. 4 29. 3 

### 6. 1 0. 4 0. 2 0. 0 0. 0 10 0 115 2 

### 5. 2

62. 3 27. 4 

### 4. 9 0. 2 0. 0 0. 0 0. 0 10 0 57 6 6. 6

61. 8 28. 5 

### 3. 1 0. 0 0. 0 0. 0 0. 0 10 0 28 8 7. 8

61. 5 28. 1 

### 2. 6 0. 0 0. 0 0. 0 0. 0 10 0 19 2 6. 3

62. 5 28. 1 

### 3. 1 0. 0 0. 0 0. 0 0. 0 10 0 9 6 8. 3 59. 4 28. 1 

### 4. 2 0. 0 0. 0 0. 0 0. 0 10 0 9 6 6. 3 63. 5 28. 1 

### 2. 1 0. 0 0. 0 0. 0 0. 0 10 0 9 6P.3 9

B- 3
Tabl e B- 1 Continue d
Non-Contiguou s Reading s Smck e Ccncraccr . Slac k Smok e licai
. Observe d Opacit y
0 t o 5 5 t o 1 0 1 0 t o 1 5 1 5 t o 2 0 2 0 t o 2 5 2 5 t o 3 0 3 0 t o 3 5 >3 5
Tota l Sampl e Siz e Highes t

2 

# I 0 0 15. 5 39. 7 37. 9 6. 9 0 0 10 0 5 8 .-

i w t i I a g. L Highes t 4 

# I 0 0 23. 3 48. 3 2. 5 3. 3 0 0 10 0 6 0 l i g 1 i.Ult-- - Highes t 8 

# 1 0 5. 2 34. 5 46. 6 12. 1 1. 7 0 0 10 0 5 8 Highes t 1 2

_ % 0 10. 6 37. 9 34. 8 13. 6 3. 0 0 0 10 0 6 6 Smck e Generate : V.liit e See k
L'lcai i Observe d Opacit y
0 t o 5 5 t o 1 0 1 0 t o 1 5 1 5 t o 2 0 2 0 t o 2 5 2 5 t o 3 0 3 0 t o 3 5 >3 5
Tota l Sampl e Siz e Highes t

2 

### Z 0. 0 3. 0 31. 3 35. 4 13. 1 16. 2 1. 0 0. 0 10 0 9 9 r.vferag

i Highes t 4 

# I 0. 0 3. 7 34. 7 34. 7 14. 9 11. 9 0. 0 0. 0 10 0 10 1 :.£

iiZl e Highes t 8 % 0. 0 9. 8 45. 1 24. 5 16. 7 3. 9 0. 0 0. 0 10 0 10 2 Highes t

1 2

_ % 0. 0 18. 8 45. 5 15. 2 18. 8 1. 9 C O 0. 0 100

- 11 2

Riverben d Stea m Z t o 5 5 t o 1 0 1 0 t o 1 5 1 5 t o 2 0 2 0 t o 2 5 2 5 t o 3 0 3 0 t o 3 5 >3 5
Tota l Sampl e Siz e 0

21. 7 36. 7 23. 3 16. 7 1. 7 0 0 10 0 6 0 Station ,

0 35. 9 28. 1 25. 0 10. 9 0 0 0 10 0 6 4 Whit e Smok e

0. 0 42. 2 35. 9 14. 1 7. 8 0 0 0 10 0 6 4 0. 0 51. 6 29. 7 18. 8 0. 0 0. 0 0. 0 0. 0 10 0 6 4

—Non-contiguou s an d contiguou s reading s define d i n Tabl e A-l
.

### B- 4 P.40
.

Tabl e B- 2 Frequenc yDistribution s o f Mea n Observe d Opacit y

Whe n Mea n Tru e Opacit y< 10 % fo r Contiguou s an d 

### 1/
. Non-Contiguou s Readings

Station , an d Smok e Typ e ByAveragin g Time ,

Smok e Generator , Blac k Smoke , Contiguou s Reading s Mean Observe d Opacit y 0 t o 5 " 5 t o 1 0 1 0 t o 1 5 1 5 t o 2 0 2 0 t o 2 5 2 5 t o 3 0 Tota l Sampl e Siz e 3 0 sec .

% 2. 6 45. 2 47. 0 5. 2 0. 0 0. 0 10 0 27 0 1 min
.

% 4. 1 44. 3 51. 6 0. 0 0. 0 0. 0 10 0 12 2 Averagin g Time 2 min
. % 2. 7 58. 1 39. 2 0. 0 0. 0 0. 0 10 0 7 4 3 min
. 4

% 0. 0 65. 6 34. 4 0. 0 0. 0 0. 0 10 0 3 2 min
.

%

— 5 min
.

%

— 6 min
.

. '/

—

Smok e Generator , Whit e 0 t o 5 5 to 1 0 1 0 t o 1 5 1 5 to 2 0 2 0 t o 2 5 2 5 t o 3 0 Tota l Sampl e Siz e 5. 6

53. 0 32. 7 7. 7 1. 0 0. 0 10 0 61 1 7. 9

52. 5 33. 2 6. 1 0. 3 0. 0 10 0 34 3 Smoke ,

12. 0 51. 1 30. 4 6. 5 0. 0 0. 0 10 0 18 4 Contiguou s

18. 0 39. 0 33. 0 10. 0 0. 0 0. 0 10 0 10 0 Reading s

4. 0 50. 0 42. 0 4. 0 0. 0 0. 0 10 0 5 0 2. 0

54. 9 39. 2 3. 9 0. 0 0. 0 10 0 5 1 2. 3

83. 7 14. 0 0. 0 0. 0 0. 0 10 0 4 3

Riverben

d Stea m 0 t o 5 5 t o 1 0 1 0 t o 1 5 1 5 to 2 0 2 0 t o 2 5 2 5 t o 3 0 Tota l Sampl e Siz e 3. 3

77. 0 15. 7 3. 9 0. 2 0. 0 10 0 46 0 Station ,

4. 8 82. 0 10. 5 2. 6 0. 0 0. 0 10 0 22 8 Whit e Smok

e 6. 7 76. 7 13. 3 3. 3 0. 0 0. 0 10 0 12 0 . , Con t

7. 5 77. 5 12. 5 2. 5 0. 0 0. 0 10 0 8 0 Lguou s Reading s

7. 5 70. 0 22. 5 0. 0 0. 0 0. 0 10 0 4 0 7. 5

75. 0 15. 0 2. 5 0. 0 0. 0 10 0 4 0 5. 0

80. 0 12. 5 2. 5 0. 0 0. 0 10 0 4 0P.4 1

B- 5

Tabl e B- 2 Continue d

Riverben d Stea mStation , Whit e Smoke , Averag e o f Tw o Observers , Contiguou s Reading s Mea n Observe d Opacit y 0 t o 5 5 t o 1 0 1 0 t o 1 5 1 5 t o 2 0 2 0 t o 2 5 2 5 t o 3 0 Tota l Sampl e Siz e 3 0 sec .

% 6. 1 79. 6 12. 8 1. 6 0. 0 0. 0 10 0 69 0 1 min
.

% 8. 8 81. 9 8. 2 1. 2 0. 0 0. 0 10 0 34 2 Averagin g Time

2 min
. 3 min
. % % 10. 6 12. 5 75. 0 75. 8 11. 7 9. 2 2. 8 2. 5 0. 0 0. 0 0. 0 0. 0 10 0 10 0 18 0 12 0 4 min
. % 10. 0 75. 0 15. 0 0. 0 0. 0 0. 0 10 0 6 0 5 min
.

% 13. 3 75. 0 8. 3 3. 3 0. 0 0. 0 10 0 6 0 6 min
.

% 10. 0 81. 7 8. 3 0. 0 0. 0 0. 0 10 0 6 0

Smok e Generator , Whit e Smoke , Non-Contiguou s Reading s Highes t 2 Highes t

4 Highes t

8 Highes t

1 2 0 t o 5 5 t o 1 0 1 0 t o 1 5 1 5 t o 2 0 2 0 t o 2 5 2 5 t o 3 0 Tota l Sampl e Siz e 0. 0 18. 2 68. 2 13. 6 0. 0 0. 0 10 0 2 2 52. 0 44. 0 4. 0 0. 0 0. 0 0. 0 10 0 2 5

Stea mStation , Whit e Smoke , Non-Contiguou s Reading s 0 t o 5 5 t o 1 0 1 0 t o 1 5 1 5 t o 2 0 2 0 t o 2 5 2 5 t o 3 0 Tota l Sampl e Siz e 0. 0

36. 4 48. 5 15. 2 0. 0 0. 0 10 0 3 3 0. 0

64. 7 26. 5 8. 8 0. 0 0. 0 10 0 3 4 0. 0

63. 2 28. 9 5. 3 2. 6 0. 0 10 0 3 8 0. 0

72. 5 20. 0 7. 5 0. 0 0. 0 10 0 4 0

—Non-contiguou s an d contiguou s reading s define d i n Tabl e A-l
.

- = Sampl e siz e les s tha n 2 0 observations
.P.4 2

Appendi x C Estimatio n o f th e Measuremen t Erro r o f A n Observe rP.4 3



### C- 1

Estimation o f th

e Measuremen t Erro r o f A n Observe r

I n Section 3 o f thi s report , mentio n wa s mad e o f th e variou s contri

bution s t o th

e varianc e o f mean deviation s ove r al l run s an d observer s (e.g. , betwee n ru

n variation , measuremen t error...)
. I n thi s appendix , a descriptio n i s give n o f howRT I estimated thes e contribution s for differen t averagin

g times
. I n particular , RT I wa s interested i n removin g th e con tribution s t o th

e varianc e o f mean deviation s o f difference s betwee n run s
an d observer s s o tha t an observer' s measuremen t erro r (i.e. , the s.d
. o f
an observer' s deviation s i n repeated measurements ) coul d be examined fo r differen t averagin

g times
. T o begi n wit hRT I assumed tha t the followin g mode l represented th e
mea n deviation , Y , , , fo r ru n i , observe r j an

d averagin

g tim e t :

Y ij k = u + R i + ° j + RO i j + e ij k i = 1,2,..
. ,r ; (C-1 ) j » 1,2,...,o ; an

d k = • 1,2,.
. .,n(t)
. wher e r = numbe r o f runs ,

o = numbe r o f observers , n(t ) = numbe r o f averagin g time s pe r ru

n pe r observe r fo r averagin g tim e t (e.g. , n(t ) = 1 for a 6-minut e averagin g time) ,
u = overal l mean whic hi s a constant , 2 R . *- » effec t o f ru

n i wit hzer o mean an d varianc e a , i r 2 0
. = effec t o f observe r j wit hzer o mean an d varianc e a , 3 o RO. . = effec t o f interaction betwee n observe r j an d ru n i wit hzer o 1 J 2 mea n an d varianc e a ,

r o
e.. , = rando

merro r fo r t averagin g tim e wit hzer o mean an

d varianc e a (i.e. , squar e o f observe r measuremen t error)
. 2 The mode l give n i n (C-1 ) i s called a varianc e component s mode l an d a ,

### C- 2

2 2 2 <z, 7 and a ar e calle d varianc e components . Usin g th e abov e model , o r o e t th e varianc e o f Y , i s give n by :

Var(Y, ( 

### ^ ) = o 2 

### + a 2 

### + a 2 

### + a * (C-2 ) ij k r o r o e t Equatio n (C-2 ) represent s th e varianc e o f mea n deviation s take n ove r run s
and observers
. Th e standar d deviation s give n i n Tabl e 4 o f thi s repor t estimat e th e squar e roo t o f Equatio n (C-2 ) fo r variou s averagin g times
. • However , i f on e i s onl yintereste d i n estimatin g th e varianc e o f a singl e observe r i n repeate d measurement s durin g th e sam e ru n (i.e. , observe r " 2 measuremen t error ) the n a n estimat e o f onl ya i s desired
. Thus , Tabl e 5 o f thi s repor t present s estimate s o f W o = a . 2 2 2 I n orde r t o estimat e th e varianc e componen t a (a s wel l a s a , o 2 an d a ) RT I use d th e Analysi s o f Varianc e Procedur e (se e [4] ) whic h r o equate s calculate d mea n square s t o thei r expecte d value s and solve s th e resultin g equation s fo r th e varianc e components . Tabl e C- 1 present s th e 2 2 2 2 resultin g estimate s o f o , a , a and a byaveragin g time , statio n and 2 smok e type . Not e i n th e tabl e tha t th e estimat e o f o i s equa l t o th e Erro r M S (excep t fo r averagin g tim e = 6 minutes ) sinc e th e expecte d valu e 2 o f th e Erro r M S unde r mode l (C-1 ) i s equa l t o o . Fo r averagin g tim e equa l t o 6 minute s ther e i s onl yon e observatio n pe r run ; and therefore , 2 2 th e expecte d valu e o f th e Erro r M S i s equa l t o C J + a Thus , i n thi s r o e t 2 "2 * 2 cas e RT I estimate d a a s u = MS E - a (a t 3 minutes)
. Th e estimate s

e t e t r o 2 2 2 o f a , a and a i n th e tabl e ar e approximat e estimate s (slightl ybiased ) i n th e sens e tha t th e expecte d mea n square s wer e assume d t o b e fo r balance d dat a (i.e. , equa l number s o f observation s fo r eac hru n and observer)
. However , thi s bia s shoul d b e small
. I t i s als o importan t t o not e tha t th e estimate s give n i n Tabl e C- 1 ar e onl yfo r averagin g time s wher e mea n tru eP.4 5

C- 3

opacit yi s greate r tha n 1 0 percent . RT I compute d th e estimate s fo r thi s leve l o f tru e opacit yt o accoun t somewha t fo r th e fac t tha t th e varianc e
o f mea n deviation s depend s o n th e leve l o f mea n tru e opacit y(thi s i s quit e eviden t i n Tabl e 4)
. Th e estimate s fo r mea n tru e opacit yles s tha n 1 0 percen t wer e no t compute d i n th e presen t study
. "2 Tabl e C- 1 indicates , a s on e woul d expect , tha t a decrease s signif

icantl ywit haveragin g tim e whil e i n genera l a , a an d a d o not . Thi s i s du e t o th e fac t tha t increasin g th e averagin g tim e implie s averagin g
ove r additiona l observation s withi n a ru n and observer ; an d therefore , onl y 2 2 2 a i s affected
. Th e tabl e als o indicate s tha t o i s muc hlarge r tha n a . e t r ° o 2 2 2 Test s o f significanc e o f a , a and a indicate , fo r almos t al l case s

6 r o r o give n i n Tabl e C-1 , tha t thes e varianc e component s ar e significantl y differen t fro mzero .

~ 2 I n examinin g th e estimate s o f a give n i n Tabl e C-1 , on e woul d ex pec t tha t th e estimate s fo r a 6-minut e averagin g tim e woul d b e eve n smalle r tha n observed , relativ e t o a 30-secon d averagin g tim e i f a n observer' s reading s withi n a ru n wer e uncorrelated
. However , th e presenc e o f corre latio n betwee n contiguou s reading s bya n observe r tend s t o somewha t re duc e th e effec t o f averaging
. A s a n exampl e o f th e effec t o f thi s corre lation , conside r th e following : Suppos e tha t th e varianc e o f a n observer' s readin g (X. ) withi n

2 a ru n = a . No wi f on e average s two o f th e observer' s reading s (X.
. an d X_ ) withi n th e ru n and th e reading s ar e independent , the n th e varianc e o f th e averag e wil l b e X,+X , a 2 , T T / 1 2 ^ e . 2 Var(—=— ) = —- r = . 5 a . z i. e However , i f th e tw o reading s ar e no t independen t bu t hav e aP.4 6



### C- 4

correlation = r , the n th e varianc e o f th

e averag e wil l b e

X l + X 2 a e 

### Var(-^—£ ) =- f (2+2r)
. Thus , i f r a
. 8 the

n
X.+X , 3. 6 a 2 ' VarH^ ) - —,-S

- = . 9 a l &

an d the averagin

g o f the tw

o correlated reading s ha s decrease d the varianc e b

ya relativel ysmal l amoun t compared t o the cas e
o f averagin

g tw o independen t readings
.

### C- 5

Tabl e C-1
. Analysi s o f Varianc e an d Estimate s o f Varianc e Component s fo r Mea n Tru e Opacity>10% ; B yAveragin

g Time , Station j c , -

r 1/2 / an d Smok e Typ e

Sourc e o f Variatio n 

### Ru n Observe r Run x Observe r Erro r TOTA L

Estimate s of,Varianc e Component s "2

a =B r n2 a =

' 2 a = r o

' 2 e t 

### 3 0 d f 1 5 ^ 

### 4 5 

### 53 2 59 5 Smok e Generator ,
sec . 

### M S 641.0 0 605.0 0 54.2 4 17.3 4
15.7 7
3.7 0
3.9 7
17.3 4 Blac k

Averagin

g Time 1 min
. d f M S 1 5 325.2 0 3 290.6 7 4 5 27.7 1 24 0 16.6 3 

### 30 3 15.6 6

3.4 6
2.3 4
16.6 3 

### 3 d f 1 5 

### 3 4 5 4 8 

### 11 1 Smok e min
. 

### M S 115.2 7 88.6 7 9.3 6 7.8 6
15.1 3
2.8 3 

### .8 5
7.8 6 

### 6 d f 1 4 

### 3

— 

## 4 2 5 9 min
. 

### MS 64.2 9 37.0 0

4.4 8
14.9 5 2.1 7

3.63 ^



### Ru n Observe r Ru n x Observe r Erro r TOTA L

Estimate s o f Varianc e Component s . 2

a = • r -2 a = o

~ 2 a = r o

~ 2 a , . = e t 

### d

f 1 8 

## 32 / 5 4 

### 51 2 58 7 MS 693.4 4 72.0 0 43.0 7 12.6 6
20.9 9
.2 0
3.9 2
12.6 6 mok e 

### d f 1 7 

### 3 5 1 

### 23 2 30 3 Generator , 

### M S 393.4 1 48.6 7 21.6 3 6.5 4
22.0 2

. .3 6
3.5 8
6.5 4 Whit e 

### df 1 7 

### 3 5 1 3 2 

### 10 3 Smok e 

### MS 114.5 3 15.2 3 7.0 6 5.2 0
18.6 6
.3 2
1.2 9
5.2 0 

### df

1 3 

### 3

— 

### 3 9 5 5 M S 92.3 8 3.3 3

4.3 8
22.0 0 

### .0 0

3.09 ^

### C- 6

Tabl e C-1
. Continue d

Sourc e o f Variatio n Ru n Observe r Ru n xObserve r Erro r TOTA L

Estimate s o f Varianc e Component s « 2



### a = r
~ 2
a = • 0


### " 2 a = • r o

~ 2 < * - a 

### e t 3 0 d f 1 5 3 4 5 60 4 66 7 Riverben d Stea m Station , Whit e Smok e
sec . M S 776.4 7 565.0 0 103.7 3 11.6 1
16.1 7 2.7 7 8.8 6 11.6 1 Averagin g Tim e

1 min
. d f M S 1 5 408.1 3 3 372.3 3 4 5 52.2 0 27 6 8.6 4 33 9 16.7 9 3.7 8 8.2 0 8.6 4 3 d f 1 3 3 3 9 5 6 11 1 min
. MS 146.5 4 146.6 7 19.0 3 3.4 0
15.9 4 4.5 6 7.8 2 3.4 0 6 d f 1 3 3

— 

### 3 9 5 5 min
. MS 73.2 3 73.3 3

9.5 1
15.8 7 4.5 4

1.69* /

—Analysi s fo r contiguou s reading s only
. 2 /

—d f 3 

### degree s o f freedom , M S = mea n squar e 3 /

—Fo r th e smok e generator , onl ydat a fro m4 o f th e 9 observer s wa s use d t o estimat e th e varianc e components . Thi s wa s don e t o eliminat e a computationa l proble mdu e t o th e relativel ylarg e numbe r o f degree s o f freedo mfo r th e interactio n betwee n run s an d observers
. 4 / "2 2 2

—a estimate d fo r 6 minute s byassumin g a fo r 6 minute s • a fo r e ro - r o 3 minutes ; e.g. , fo r blac k smok e a t 6 minutes ; a = 4.4 8 - .8 5 = » 3.63
. e t