United States

Environmental Protection

Agency

Air and Radiation EPA420-P-98-019

March 1999

M6.FLT.006

Soak Length Activity

Factors for Diurnal

Emissions

DRAFT

 Printed on Recycled Paper
EPA420-P-98-019

March 1999

Soak Length Activity Factors for Diurnal Emissions

M6.FLT.006

DRAFT

Assessment and Modeling Division

Office of Mobile Sources

U.S. Environmental Protection Agency

NOTICE

This technical report does not necessarily represent final EPA decisions or positions.

It is intended to present technical analysis of issues using data which are currently available.

The purpose in the release of such reports is to facilitate the exchange of

technical information and to inform the public of technical developments which

may form the basis for a final EPA decision, position, or regulatory action.
m6flt006.wpd DRAFT 1 Mar 1, 1999

- Draft -

Soak Length Activity Factors for Diurnal Emissions

Report Number M6.FLT.006

Last Revised on March 1, 1999

Edward L. Glover

U.S.EPA Assessment and Modeling Division
m6flt006.wpd DRAFT 2 Mar 1, 1999

1.0 INTRODUCTION

MOBILE6 will compute and report (as a user option) hourly emission factors for

start, running, and evaporative emissions. These will be in addition to the standard daily

emission estimates which are currently calculated by MOBILE5. The hourly emission

factors will allow the MOBILE6 model to provide more precise output that accounts for the

time of day that vehicle emissions occur. The temporal distribution of emissions is an

important factor in the formation of diurnal evaporative emissions. 

The hourly emission estimates require considerable vehicle activity information and

analysis. The term “activity” refers to the vehicle’s operating mode such as running, idling,

parked (soaking), etc. The specific activity information includes soak durations, time of

soak, trip lengths, time of trip, and other information. This document (M6.FLT.006)

discusses the issue of vehicle soak time as it pertains to diurnal emissions. Other activity

estimates needed to develop daily emission factors for hot soak, running loss, start and

running exhaust emissions, and resting loss emissions will be documented in other

MOBILE6 documents listed with the report numbers “M6.FLT.XXX”. Also, for general

information on evaporative emissions and their modeling in the MOBILE6 model, the

reader is encouraged to review “M6.EVP.001" and “M6.EVP.002".

2.0 DATA SOURCES USED

The primary data source for this analysis is an EPA instrumented vehicle study

conducted in Baltimore, Spokane and Atlanta. In these studies, instrumentation to monitor

vehicle usage was installed with the motorists’ permission on 168 randomly selected

vehicles while they were tested at an Inspection / Maintenance (I/M) station. The motorists

returned one or two weeks later to have the instrumentation removed. Information from

more than 8,500 vehicle-trips was recorded. The raw data collected from the study were

processed by the Radian Corporation under EPA contract to create a “trip characteristics”

file. This processed file was used to develop the hourly soak time distributions. For more

details regarding the instrumented vehicle study and the data processing, please refer to the

document “Travel Trip Characteristics Analysis” Final Report under EPA Contract 68-C1-

0079 WA 2-05 with Sierra Research. 

3.0 METHODOLOGY FOR DIURNAL EMISSION ACTIVITY

This section describes the basic methodology to develop the trip length activity

estimates used to calculate diurnal emissions. The process consisted of several steps.

These are discussed below.
m6flt006.wpd DRAFT 3 Mar 1, 1999

3.1 Definitions

3.1.1 Diurnal Emissions

Diurnal emissions are evaporative emissions which may escape from a non-running

vehicle subsequent to its hot soak, and while it is exposed to a thermal gradient cycle of

sufficient magnitude. Emissions are produced primarily during and immediately following

the portion of the cycle when temperatures rise. Diurnal emissions are defined as excluding

emissions that occur during vehicle running, starting, or hot soak operation. They also

generally occur over a period of time of several hours, and must be apportioned to the

various hourly groups. 

For purposes of the MOBILE6 model, three types of diurnals can occur. The first

type is the multi-day diurnal. This type occurs if a vehicle is operated, and then “soaks” (is

parked) for two or more days, and experiences two or more cycles of sufficiently large

thermal gradients during the multi-day soak period to raise fuel tank temperatures past a

threshold value. The second type is the full or one-day diurnal. This type of diurnal needs

to begin prior to the beginning of the temperature rise (i.e., prior to 6AM), and can last for

up to 24 hours. The third type is the interrupted diurnal. This type is similar to the

previous ones, except that the soak periods range from a minimum of one hour up to 24

hours, and they start later in the day (i.e., the vehicle is operated during the morning so that

the early morning heat build (begins at 6 AM) is interrupted). The diurnals which range

from 25 hours to 48 hours are a combination of a one day diurnal and an interrupted diurnal

or multi-day depending on when they start. 

Depending on the length of the soak, the full diurnal and the interrupted diurnal may

represent only a fraction of the thermal cycle. Also, in terms of activity parameters, the

MOBILE6 model diurnal activity parameters will reflect vehicles which experienced more

than one interrupted diurnal during the day. Their contribution is a function of the length

and timing of vehicle trips during the day. For example, a vehicle that makes a quick trip

from 10:00 to 10:20 AM, and is parked until sundown will be reflected in the hourly

activity parameters as part of a full diurnal (from 6 AM to 10 AM), and an interrupted

diurnal from 12:20 AM until sundown. During the two hour period between 10:20 AM and

12:20 AM the vehicle is in hot soak mode.

3.1.2 Hourly Diurnal Activities

For this analysis of vehicle activity, hourly diurnal activity estimates have a

different basis than hourly running emission activity estimates. Where the hourly running

emissions are based on the number and/or length of trips in the given hour, the hourly

diurnal activity estimates are based on whether a multi-day, full day, or interrupted diurnal

occurred during that hourly group. For example, a vehicle can have several trips during a
m6flt006.wpd DRAFT 4 Mar 1, 1999

given hourly group interval; however, a vehicle is either experiencing a diurnal during a

given hourly group interval, or not experiencing it during the given hourly interval. In other

words the analysis assumed that each vehicle in the database could have either one or no

diurnals during a given hour on a given day. 

3.2 Hourly Intervals

The 24 hour day was divided into 14 different hourly groups. Thirteen of these

groups have a duration of one hour. These start at 6:00AM and run through 6:59:59PM.

The fourteenth group contains the remaining nighttime hours as one interval. Collapsing

these hours into one group was done for three reasons: (1) the emissions contributed during

the night have a relatively smaller impact on daily ozone than those contributed during the

morning or day, (2) there were relatively little data for these time periods, and (3) what data

were available produced results which showed very little hour to hour variance. The hourly

intervals are shown in Table 1. In addition to its use for diurnal activity estimates, the same

hourly group structure is used in the calculation of activity estimates for start emissions,

running emissions, hot soak emissions, resting loss emissions, and running loss emissions.
m6flt006.wpd DRAFT 5 Mar 1, 1999

Table 1

Hourly Ranges

Group Name Hourly Range Time

6 6 - 7 6 am to 7 am

7 7 - 8 7 am to 8 am

8 8 - 9 8 am to 9 am

9 9 - 10 9 am to 10 am

10 10 - 11 10 am to 11 am

11 11 - 12 11 am to noon

12 12 - 13 noon to 1 pm

13 13 - 14 1 pm to 2 pm

14 14 - 15 2 pm to 3 pm

15 15 - 16 3 pm to 4 pm

16 16 - 17 4 pm to 5 pm

17 17 - 18 5 pm to 6 pm

18 18 - 19 6 pm to 7 pm

24 19 - 24 and 24 - 5 7 pm to 6 am

3.3 Identifying the Hourly Diurnals in the Database

The instrumented vehicle database consists of ‘trip’ type data. This means that the

initial vehicle start time and stopping times were recorded while the vehicles were

operating. The database was based on more than 8,500 vehicle trips, and the corresponding

number of prior and subsequent soaks. For this analysis, the individual trip data were not

used directly since the activity information was needed on an hourly basis rather than on

a per trip basis. In essence, it was necessary to know for a given hourly group interval the

number of vehicles which were experiencing a diurnal, and the number of vehicles which

were in running mode or in hot soak mode.

Examination of the roughly 8,500 vehicle trips showed 168 vehicles, and 1,425

vehicle-days of data in the sample. The concept of vehicle-days was used instead of trips
m6flt006.wpd DRAFT 6 Mar 1, 1999

because diurnals can occur over several hours, and each vehicle can experience either one

or zero diurnals in a given hour of a day. For example, at 6 to 7 AM, a vehicle is either

experiencing a diurnal or running / hot soaking (not experiencing a diurnal). The 1,425

vehicle-days were reduced down to 1,257 valid vehicle-days by omitting each vehicle’s first

day of operation in the program. The omission of each vehicle’s first test day was

necessary because the length of the soak prior to the installation of the instrumentation was

not known. For example, if vehicle #10 were operated for 14 days in the program, it would

account for 13 valid vehicle-days.

Creating the 13 hourly groups (nighttime group 14 was omitted) for diurnal

activities was necessary because diurnal emissions are a function of time of day and

duration of soak. For example, on a day with a typical temperature cycle, the diurnal

emission effect on the 11 to 12 AM interval after an eight hour soak will likely be larger

than the diurnal emissions on the 6 to 7 AM interval after an eight hour soak. 

Once the database was organized into 1,257 valid vehicle-days, it was necessary to

determine for each of the 13 hourly groups whether a diurnal had occurred on each of the

1,257 valid vehicle-days, and the soak duration prior to the beginning of the hourly group.

By definition, a diurnal occurred if the vehicle was NOT operating, or had NOT operated

in the previous two hours. In practice this will be slightly more than two hours because the

data could not be analyzed on a basis any finer than by hour. For example, if a vehicle

started at 7:35 AM, it was assumed to start at 7:00 AM. Also, by the definition, it was

assumed that diurnal emissions would be very small in magnitude during the nighttime

hours of 7 PM to 6 AM (group 14), although a vehicle’s soak period could encompass part

or all of this time interval. As a result, the activity distribution for the 6 PM to 7 PM group

will be used for the nighttime hours.

For each hour, the duration of the preceding soaks were grouped in 12 intervals.

These intervals are shown in the first column of Table 2. They range from a soak duration

of 1 to 2 hours up to a multi-day soak of 72 hours or more. The 12th row (labeled “running

/ hot soak”) contains the percentage of vehicles which were not experiencing a diurnal

during a given hourly group. For example, the fifth column of the fourth row of numbers

in Table 2 says that 1.67 percent of the valid vehicle-days had soaks which started between

four and five hours prior to 10 AM, and did not include any vehicle operation between 10

and 11 AM.

For illustration, the hourly diurnal activity results are shown in Table 2 for all of the

hourly groups and for a range of soak hours. The percentages in each column add to 100

percent and include vehicles which are not having a multi-day, full, or an interrupted

diurnal (See Section 4.3 for definition of diurnal types). The percentage of vehicles in a

given hourly group which are likely experiencing a multi-day diurnal are those in the rows

labeled as 48 to 71 and 72+. The percentage of vehicles which are likely (there are a few

exceptions depending on when the soak began) experiencing a full diurnal plus an
m6flt006.wpd DRAFT 7 Mar 1, 1999

interrupted diurnal are those in the row labeled 24 to 47. The percentage of vehicles which

are experiencing an interrupted diurnal are in the rows labeled 1 to 2 through 8 to 23. For

example, the table shows that at the 6 to 7 AM interval, 61.02% of the vehicles are

experiencing a soak which has lasted between 8 and 24 hours. For comparison, by 3 to 4

PM, the percentage of vehicles in this category (8 to 24) has dropped to less than 6 percent.

3.4 Hourly Diurnal Activity Results

To apply the activity distribution to all soak lengths and to smooth the distribution

curve, MOBILE6 will apply activity values using a distribution curve. The actual diurnal

activity distribution parameters which will be used in MOBILE6 are shown in Table 3. A

set of four parameters (A, B, C, and D) is shown for each of the 13 hourly groups. The 6 -

7 group is the distribution for the 6 to 7 AM group, the 18+ group is the distribution for all

the evening and nighttime hours between 7 PM and 6 AM. These parameters are the result

of fitting Weibull equations (non-linear regression) to the diurnal activity results. Fitting

the Weibull equations to the activity results produces a smoother activity distribution for

the individual hourly groups than is shown in Table 2. The smoothness of the curve is

reflected in the high r-square values (> 0.97) of the fit. Using the fitted value for the

distribution was done in-order to conform to the structure of the diurnal emission factors

being built into MOBILE6. These require some fairly small time intervals. If the unfitted

data were used directly, some of these intervals would be represented by no data or only a

very small amount of data.

The Weibull function fit is of the form:

Y = A - B * exp( -C * Soaklength**D ) Eqn 1

where A, B, C, and D are regression coefficients (listed in Table 3), and soaklength in hours

(1 to 72+) is the independent variable. The variable Y is the cumulative distribution in

percent.

The Weibull function fit is a cumulative distribution of the soaks which are

diurnals. It does not include the portion of the fleet which is in hot soak or running mode.

For example, substituting the coefficients for Hourly Group 6 - 7 from Table 3 and a soak

length of 72 hours into Equation 1 produces a maximum cumulative distribution of 85.0

percent. The remaining 15 percent of the fleet is in hot soak or running mode.

0.850 = 0.8502 - 0.8427 * exp(-0.001616 * 72 ** 2.6440) Eqn 2
m6flt006.wpd DRAFT 8 Mar 1, 1999

In the MOBILE6 model it will be necessary to calculate the percentage of soaks in

a given hourly group which are X hours in duration. This is done by transforming the

cumulative Weibull distribution into a non-cumulative distribution using Equation 3.

D(i) = Y(i) - Y(i-1) Eqn 3

where D(i) is the distribution for the interval from t-1 to t, Y is the Weibull function

from Eqn 1.

For example, for Group 6 - 7 the percentage of soaks which are 5 - 6 hours is shown in

Equations 4 and 5.

0.09822 = 0.8502 - 0.8427 * exp(-0.001616 * 5 ** 2.6440) Eqn 4

0.05906 = 0.8502 - 0.8427 * exp(-0.001616 * 4 ** 2.6440) Eqn 5

0.0392 = 0.09822 - 0.05906 Eqn 6

The value is 0.0392 or 3.92 percent of the fleet has a preceding 5 to 6 hour soak

during the 6 to 7 AM period.

The results in Table 2 and Table 3 represent both weekdays and weekends. The

combination of the two types was necessary because of a lack of data on weekends (there

were insufficient numbers of weekend vehicle-days). Inclusion of these data may bias the

weekday results slightly; however, no analysis was done to quantify this potential bias. To

overcome this potential problem, the MOBILE6 input structure will allow for optional user

input of separate weekend/weekday parameters should they become available.
m6flt006.wpd DRAFT 9 Mar 1, 1999

TABLE 2

Diurnal Activity Parameters by Hourly Group

SOAK Hrs 6 - 7 AM 7 - 8 AM 8 - 9 AM 9 - 10 AM 10 - 11 AM 11 - 12 AM 12 - 1 PM 1 - 2 PM 2 - 3 PM 3 - 4 PM 4 - 5 PM 5 1 to 2 1.27% 2.23% 5.25% 12.97% 14.88% 8.99% 7.48% 7.80% 11.14% 8.99% 10.18% 2 to 3 0.72% 1.27% 2.15% 5.09% 12.09% 13.13% 6.92% 5.41% 5.73% 8.75% 6.44% 3 to 4 1.27% 0.64% 1.19% 1.91% 4.93% 10.10% 11.30% 5.57% 4.30% 4.85% 6.52% 4 to 5 3.02% 0.95% 0.64% 1.11% 1.67% 4.77% 7.80% 10.26% 5.09% 3.98% 4.14% 5 to 6 3.50% 2.86% 0.95% 0.56% 0.95% 1.43% 4.30% 7.40% 9.39% 3.82% 3.58% 6 to 7 4.85% 2.94% 2.70% 0.72% 0.40% 0.80% 1.27% 3.90% 6.76% 8.19% 3.74% 7 to 8 5.81% 3.98% 2.63% 2.55% 0.56% 0.40% 0.64% 1.11% 3.26% 4.93% 6.05% 8 to 23 61.02% 47.81% 36.20% 29.04% 23.71% 17.90% 13.37% 9.63% 7.40% 5.89% 6.60% 24 to 47 4.93% 4.06% 3.26% 2.39% 2.07% 1.91% 1.27% 1.27% 0.95% 1.03% 0.72% 48 to 71 0.88% 0.72% 0.64% 0.56% 0.48% 0.48% 0.48% 0.40% 0.32% 0.24% 0.24% 72+ 0.48% 0.32% 0.32% 0.16% 0.08% 0.08% 0.08% 0.08% 0.08% 0.08% 0.08% running / hot soak 12.25% 32.22% 44.07% 42.96% 38.19% 40.02% 45.11% 47.18% 45.58% 49.24% 51.71% TOTAL 100.00% 100.00% 100.00% 100.00% 100.00% 100.00% 100.00% 100.00% 100.00% 100.00% 100.00% 1
m6flt006.wpd DRAFT 10 Mar 1, 1999

Table 3

Weibull Distribution Coefficients for Diurnal Activities 

Hourly

Group

Coefficient

A

Coefficient

B

Coefficient

C

Coefficient

D

Regression

R2 Value

6 - 7 0.8502 .8427 0.001616 2.6440 0.995

7 - 8 0.6559 0.6342 0.001473 2.5928 0.996

8 - 9 0.5418 0.4793 0.001880 2.4486 0.995

9 - 10 0.5525 0.3867 0.002715 2.2846 0.994

10 - 11 0.5987 0.3971 0.038477 1.3344 0.973

11 - 12 0.5950 0.8389 0.5479 0.5086 0.974

12 - 13 0.5313 0.9246 0.6797 0.4943 0.981

13 - 14 0.4995 0.6927 0.4367 0.6834 0.979

14 - 15 0.5039 0.5180 0.2147 1.0038 0.976

15 - 16 0.4630 0.4793 0.2227 1.0182 0.981

16 - 17 0.4361 0.3870 0.1233 1.3237 0.989

17 - 18 0.4400 0.3881 0.1723 1.1886 0.996

18 + 0.5025 0.4509 0.1967 1.1494 0.998
m6flt006.wpd DRAFT 11 Mar 1, 1999

4.0 USING THE HOURLY DIURNAL ACTIVITY INFORMATION

4.1 Overview

To use the diurnal activity information in the MOBILE6 model requires that the

activity information be integrated with the diurnal emission parameters. This is not a trivial

task since both the activity information and the diurnal emission information are both

functions of time of day and soak length. Also, the task is made more difficult since several

types of diurnal emissions exist, and some of these are a function of both the time of day

being evaluated and the time that the soak began. 

4.2 Diurnal Types

Four different diurnal types are present in MOBILE6. These are Interrupted, Full,

Two-day, and Three-day. In addition, there are periods where there is no diurnal because

the vehicle is running or under a hot soak. More complete information on diurnal types and

diurnal emissions can be found in EPA documents EPA-420-P-98-011 “Modeling Hourly

Diurnal Emissions and Interrupted Diurnal Emissions Based on Real-Time Diurnal Data”

-M6.EVP.001, and M6.EVP.003 “Evaluating Multiple Day Diurnal Evaporative Emissions

Using RTD Tests”.

The emission effects of the Null diurnal (a running or non diurnal mode),

Interrupted diurnal, Full diurnal, and two and three day diurnals are all assumed to start

prior to 6 am. The interrupted diurnals are a function of the time of day at which the

diurnal started, ranging from 7am to 2pm. Each has a different emission effect as explained

in M6.EVP.002. These are labeled: “I - 7 am”, “I - 8am”, “I - 9am”, “I - 10am”, “I - 11am”,

“I - 12 am”, “I - 1pm”, and “I - 2pm”. Several of these are illustrated in the sample

calculation.

4.3 Rules for Determining Diurnal Type

The MOBILE6 model uses rules in the hourly diurnal emissions calculation to

determine how to allocate vehicle activity to each diurnal emission type. The rules are

based on which hour of the day is being modeled, the soak duration, and in the case of

interrupted diurnals, the time of day the soak began. For example, for Hour X, the activity

data will indicate what percentage of the fleet has been soaking for what period of time.

The model must allocate these activity fractions to the appropriate type of diurnal.

Knowing how much activity data to allocate to interrupted, full, two-day, and three-day

diurnal types allows MOBILE6 to properly weight each type together for each hour of the

day.
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Rules One through Four point to a case where there is no diurnal. These are the

Null diurnal cases. The vehicle is either in hot soak mode or resting loss mode. Rule Five

applies to an interrupted diurnal, and rules Six through Eight apply to full or multi-day

diurnals. Soak time refers to the length of the soak in hours, and hour refers to the hour of

the day on a 24 hour clock (i.e., 5 = 5 AM).

Table 4

Determining the Type of Diurnal

Rule # Rule Diurnal Type Explanation

Rule 1 Soaktime < 1 Hot Soak Hot Soak Period - No diurnal

Rule 2 Soaktime >= 1 and 

Soaktime < 2

Resting Loss Vehicle Equilibrating to Ambient

- No diurnal

Rule 3 Hour <= 5 (5 AM) Resting Loss Assume no diurnal emission from

midnight to 5 am

Rule 4 Soaktime <= Hour - 13 Resting Loss No diurnal beginning in

Afternoon assume no temp rise

after 3 pm.

Rule 5 Soaktime > Hour - 13 and

Soaktime <= Hour - 5

Interrupted Hot Soak ended after 6 am causes

interrupted diurnal.

Rule 6 Soaktime > Hour - 5 and

Soaktime <= Hour + 17

Full Diurnal begins at 6 am. No

significant diurnal on previous

day.

Rule 7 Soaktime > Hour + 17 and

Soaktime <= Hour + 41

Two-Day Diurnal begins at 6 am. 

Significant diurnal previous day.

Rule 8 Soaktime > Hour + 41 Three-Day Diurnal begins at 6 am. 

Significant diurnal previous two

or more days.

Application of the “diurnal rules” is shown graphically in the attached Excel

spreadsheet “Diur_Rule.xls”. It requires Excel 97, and should be viewed in color. The

overall spreadsheet contains two worksheets (Tables A-1 and A-2). The first worksheet is

a matrix with hour of the day as columns and Soaktime as rows. It shows the entire range.

The second worksheet shows only the interrupted diurnals. The reader should note that

there are several different types of interrupted diurnals based on the time of day the soak

period started. The overall worksheet matrix is color coded to represent each type of

diurnal / no diurnal. The color pink represents the periods of the day / soak combinations

when no diurnal occurs (hotsoak periods). The yellow color also represents the periods

when a diurnal does not occur. This is typically during the nighttime hours when only
m6flt006.wpd DRAFT 13 Mar 1, 1999

resting loss emissions occur. The darker blue periods near the top of the figure represent

the interrupted diurnal periods. The green portion the figure indicates when a full day

diurnal can occur. The lighter blue section of the figure with white letters represents the

two day diurnal, and the red section at the bottom represents the three day diurnal periods.

4.4 Example Calculation

An example calculation is provided in the accompanying linked (attached)

spreadsheet. This calculation is fairly lengthy and involves three separate spreadsheets

linked as document EVP_DIU2.XLS. It is attached and discussed in this section to provide

a sample calculation of the method of combining the activities with the diurnal emissions.

The sample calculation provides an estimate for diurnal emissions in grams per hour per

vehicle and grams per hour per day per vehicle for the case of 1990-93 PFI vehicles which

did not fail the purge or pressure I/M test. Other 1981 and later model year groups and

evaporative I/M test status cases would use similar calculations.

The calculations in the spreadsheet are based on incorporating the methodology

described in document EPA420-P-98-011 (or M6.EVP.002) “Modeling Hourly Diurnal

Emissions and Interrupted Diurnal Emissions Based on Real-Time Diurnal Data”, and the

diurnal activity estimates described in the current document.

The text of this example calculation is written to coincide with the Excel

spreadsheet EVP_DIU2.XLS. This spreadsheet consists of three tables. These are: FDD

“Non Gross”, “Gross Temps”, and “Hourly”. The “Non Gross” table provides an example

calculation of the average daily diurnal emission estimate for a vehicle which is not a gross

liquid leaker. The “Gross Temps” table is a calculation of the daily temperature

distribution used to calculate the diurnal emissions of the gross liquid leakers. The

“Hourly” table is the primary table. It calculates the individual hourly diurnal emissions

for each soak length of non-gross liquid leakers and gross liquid leakers, and sums them

into a daily total. The gross liquid leakers and the non-gross liquid leakers are discussed

separately in document EPA420-P-98-011 (or M6.EVP.002), and in the MOBILE6 model

because gross liquid leakers are a small portion of the vehicle fleet, but nevertheless have

a large impact on the total diurnal emissions because of their tremendous emission rates.

4.4.1 Hourly Diurnal Emissions of Non-Gross Liquid Leakers

The “FDD Non Gross” table calculates the full day diurnal (FDD) for a vehicle that

is not a gross liquid leaker (NGLL). The formulas are shown at the top of the sheet and the

result (FDD) is given at the bottom of the sheet. The value is 2.6832 grams of HC for this

example.

The value of FDD is used in the “Hourly” spreadsheet in the columns Non Gross -
m6flt006.wpd DRAFT 14 Mar 1, 1999

Diurnal grams (Worksheet “Hourly” Cells CC through CU) to calculate the hourly diurnal

emissions for each hourly group (i) at each soaktime (j). The formula which is used in each

cell of the matrix is:

Hourly Diurnal(i,j) = FDD * Diurnal Fract(i,j) * Activity Fract(i,j) Eqn 7

where hourly group i ranges from 6-7am to 11-12pm (18 groups)

where soaktime = j ranges from 1 to 72 hours

where Hourly Diurnal is the average g/vehicle for that hour, including both soaking and

non-soaking vehicles.

The ‘Diurnal Fract(i,j)’ parameter is shown in worksheet “Hourly” Cells BI-CA for

each hourly group and soaklength. The ‘rules’ used to develop the Diurnal Fract parameter

are shown in worksheet “Hourly” Cells AO-BG. The value in each of the Diurnal Fract

cells is the fraction of a daily diurnal that cell or hourly group / soak length represents. As

reported in M6.EVP.002.

The “Activity Fract(i,j)” parameter used in Eqn 7 is shown in worksheet “Hourly”

Cells U-AM. These are the fraction of an hourly group’s activity represented by one of the

soaklengths. Each column normalizes to unity (i.e., Column V sums to 1.0). The activity

values shown in worksheet “Hourly” Cells U-AM were calculated from the cumulative

activity values shown in worksheet “Hourly” Cells A-S.

The final average daily diurnal for a non-gross liquid leaker is shown in worksheet

“Hourly” cell CU. This reflects the impact of the activity distribution and the interrupted

diurnals. The value for this example of vehicles that pass both purge and pressure tests is

1.271 grams / day - non-gross liquid leaker. In comparison, the value would be 2.6832

grams /day - nongross liquid leaker if all of the fleet received a full day diurnal.

4.4.2 Hourly Diurnals of Gross Liquid Leakers

Equation 8 was used to calculate the hourly diurnal emissions of gross liquid leakers

(HDGLL). It is a function of the hourly temperature difference (difference within an hour),

and the daily temperature difference (difference between the current hour and the

temperature prior to 6:00AM). It is weighted by the activity distribution in Table 2.

HDGLL = 100.29*(0.008958 + (0.007383*Hourly DTemp) + (0.003053*Daily DTemp) ) * Activity Eqn 8

The hourly and daily temperature differences are shown in worksheet “Hourly”

(Cells CX-DP). The calculation in Equation 8 excluding the activity weighting was done

in worksheet “Hourly” (Cells DR-EJ), and the activity weighting was done in worksheet
m6flt006.wpd DRAFT 15 Mar 1, 1999

“Hourly” (Cells EL-FD).

The daily temperature difference for each hourly group and soak time is based on

the daily temperature profile found in the spreadsheet table “Gross Temps”. This table

takes the standardized temperature profile found in the Code of Federal Regulations -

40CFR86, and creates a new standardized temperature profile based on the daily minimum

and maximum temperatures. In this case, the daily minimum and maximum temperatures

were 82 F to 106 F.

For comparison, the final average diurnal emission result for liquid leakers for this

example is shown in Cell CU. It is 63.326 grams / day- gross liquid leaker. This is a very

large emission result, especially in comparison to the value of 1.271 grams / day - nongross

liquid leaker. However, the high value for the gross liquid leaker is an extreme (not close

to the average vehicle diurnal emission). Gross liquid leakers are (fortunately) relatively

rare in the fleet, and typically make up less than 1 percent. They reflect vehicles with

serious fuel system problems where liquid fuel/vapor (not just vapor) is escaping from the

system. 
m6flt006.wpd DRAFT 16 Mar 1, 1999

5.0 COMMENTS

Comments on this report and its proposed use in MOBILE6 should be sent to the attention

of the author, and submitted electronically to mobile@epa.gov, or by fax to (734)

214-4939, or by mail to MOBILE6 Review Comments, US EPA Assessment and Modeling

Division, 2000 Traverwood Drive, Ann Arbor MI 48105. Electronic submission of

comments is preferred, since we will make any comments available on our web site. In

your comments, please note clearly the document that you are commenting on including the

report title and the code number listed. Please be sure to include your name, address,

affiliation, and any other pertinent information.
Table A-1

Diurnal "Rules"

Prior

Diurnal Time Soak Time 6:00 AM noon 6 PM to 7 pm midnight to 1 am) 5:00 AM

hours hours 600 700 800 900 1000 1100 1200 1300 1400 1500 1600 1700 1800 1900 2000 2100 2200 2300 2400 100 200 300 400 500

0 hot soak hot soak hot soak hot soak hot soak hot soak hot soak hot soak hot soak hot soak hot soak hot soak hot soak hot soak hot soak hot soak hot soak hot soak hot soak hot soak hot soak hot soak hot soak hot soak

1 resting resting resting resting resting resting resting resting resting resting resting resting resting resting resting resting resting resting resting resting resting resting resting resting

0 2 F (6 am) I (7 am) I (8 am) I (9 am) I (10 am) I (11 am) I (noon) I (1 pm) I (2 pm) resting resting resting resting resting resting resting resting resting resting resting resting resting resting resting1 3 F (6 am) F (6 am) I (7 am) I (8 am) I (9 am) I (10 am) I (11 am) I (noon) I (1 pm) I (2 pm) resting resting resting resting resting resting resting resting resting resting resting resting resting resting2 4 F (6 am) F (6 am) F (6 am) I (7 am) I (8 am) I (9 am) I (10 am) I (11 am) I (noon) I (1 am) I (2 pm) resting resting resting resting resting resting resting resting resting resting resting resting resting3 5 F (6 am) F (6 am) F (6 am) F (6 am) I (7 am) I (8 am) I (9 am) I (10 am) I (11 am) I (noon) I (1 pm) I (2 pm) resting resting resting resting resting resting resting resting resting resting resting resting4 6 F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) I (7 am) I (8 am) I (9 am) I (10 am) I (11 am) I (noon) I (1 pm) I (2 pm) resting resting resting resting resting resting resting resting resting resting resting5 7 F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) I (7 am) I (8 am) I (9 am) I (10 am) I (11 am) I (noon) I (1 pm) I (2 pm) resting resting resting resting resting resting resting resting resting resting6 8 F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) I (7 am) I (8 am) I (9 am) I (10 am) I (11 am) I (noon) I (1 pm) I (2 pm) resting resting resting resting resting resting resting resting resting7 9 F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) I (7 am) I (8 am) I (9 am) I (10 am) I (11 am) I (noon) I (1 pm) I (2 pm) resting resting resting resting resting resting resting resting8 10 F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) I (7 am) I (8 am) I (9 am) I (10 am) I (11 am) I (noon) I (1 pm) I (2 pm) resting resting resting resting resting resting resting9 11 F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) I (7 am) I (8 am) I (9 am) I (10 am) I (11 am) I (noon) I (1 pm) I (2 pm) resting resting resting resting resting resting

10 12 F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) I (7 am) I (8 am) I (9 am) I (10 am) I (11 am) I (noon) I (1 pm) resting resting resting resting resting resting11 13 F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) I (7 am) I (8 am) I (9 am) I (10 am) I (11 am) I (noon) resting resting resting resting resting resting12 14 F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) I (7 am) I (8 am) I (9 am) I (10 am) I (11 am) resting resting resting resting resting resting13 15 F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) I (7 am) I (8 am) I (9 am) I (10 am) resting resting resting resting resting resting14 16 F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) I (7 am) I (8 am) I (9 am) resting resting resting resting resting resting15 17 F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) I (7 am) I (8 am) resting resting resting resting resting resting16 18 F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) I (7 am) resting resting resting resting resting resting17 19 F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) resting resting resting resting resting resting18 20 F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) resting resting resting resting resting resting19 21 F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) resting resting resting resting resting resting20 22 F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) resting resting resting resting resting resting21 23 F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) resting resting resting resting resting resting22 24 2 day (6am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) resting resting resting resting resting resting23 25 2 day (6am) 2 day (6am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) resting resting resting resting resting resting24 26 2 day (6am) 2 day (6am) 2 day (6am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) resting resting resting resting resting resting25 27 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) resting resting resting resting resting resting26 28 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) resting resting resting resting resting resting27 29 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) resting resting resting resting resting resting28 30 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) resting resting resting resting resting resting29 31 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) resting resting resting resting resting resting30 32 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) resting resting resting resting resting resting31 33 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) resting resting resting resting resting resting32 34 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) resting resting resting resting resting resting33 35 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) resting resting resting resting resting resting34 36 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) F (6 am) F (6 am) F (6 am) F (6 am) F (6 am) resting resting resting resting resting resting35 37 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) F (6 am) F (6 am) F (6 am) F (6 am) resting resting resting resting resting resting36 38 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) F (6 am) F (6 am) F (6 am) resting resting resting resting resting resting37 39 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) F (6 am) F (6 am) resting resting resting resting resting resting38 40 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) F (6 am) resting resting resting resting resting resting39 41 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) resting resting resting resting resting resting40 42 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) resting resting resting resting resting resting41 43 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) resting resting resting resting resting resting42 44 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) resting resting resting resting resting resting43 45 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) resting resting resting resting resting resting44 46 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) resting resting resting resting resting resting45 47 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) resting resting resting resting resting resting46 48 3 day (6 am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) resting resting resting resting resting resting47 49 3 day (6 am) 3 day (6 am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) resting resting resting resting resting resting48 50 3 day (6 am) 3 day (6 am) 3 day (6 am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) resting resting resting resting resting resting49 51 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) resting resting resting resting resting resting50 52 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) resting resting resting resting resting resting51 53 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) resting resting resting resting resting resting52 54 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) resting resting resting resting resting resting53 55 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) resting resting resting resting resting resting54 56 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) resting resting resting resting resting resting55 57 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) resting resting resting resting resting resting56 58 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) resting resting resting resting resting resting57 59 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) resting resting resting resting resting resting58 60 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) resting resting resting resting resting resting59 61 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 2 day (6am) 2 day (6am) 2 day (6am) 2 day (6am) resting resting resting resting resting resting60 62 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 2 day (6am) 2 day (6am) 2 day (6am) resting resting resting resting resting resting61 63 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 2 day (6am) 2 day (6am) resting resting resting resting resting resting62 64 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 2 day (6am) resting resting resting resting resting resting63 65 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) resting resting resting resting resting resting64 66 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) resting resting resting resting resting resting65 67 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) resting resting resting resting resting resting66 68 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) resting resting resting resting resting resting67 69 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) resting resting resting resting resting resting68 70 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) resting resting resting resting resting resting69 71 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) resting resting resting resting resting resting70 72 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) 3 day (6 am) resting resting resting resting resting resting

Di_rule.xls 3/8/99
Table A-2

Rules for Interrupted Diurnals

Prior

Diurnal Time Soak Time 6:00 AM noon 6 PM to 7 pm midnight to 1 

hours hours 600 700 800 900 1000 1100 1200 1300 1400 1500 1600 1700 1800 1900 2000 2100 2200 2300 2400

0

1

0 2 I (7 am) I (8 am) I (9 am) I (10 am) I (11 am) I (noon) I (1 pm) I (2 pm)

1 3 I (7 am) I (8 am) I (9 am) I (10 am) I (11 am) I (noon) I (1 pm) I (2 pm)2 4 I (7 am) I (8 am) I (9 am) I (10 am) I (11 am) I (noon) I (1 am) I (2 pm)3 5 I (7 am) I (8 am) I (9 am) I (10 am) I (11 am) I (noon) I (1 pm) I (2 pm)4 6 I (7 am) I (8 am) I (9 am) I (10 am) I (11 am) I (noon) I (1 pm) I (2 pm)5 7 I (7 am) I (8 am) I (9 am) I (10 am) I (11 am) I (noon) I (1 pm) I (2 pm)6 8 I (7 am) I (8 am) I (9 am) I (10 am) I (11 am) I (noon) I (1 pm) I (2 pm)7 9 I (7 am) I (8 am) I (9 am) I (10 am) I (11 am) I (noon) I (1 pm) I (2 pm)8 10 I (7 am) I (8 am) I (9 am) I (10 am) I (11 am) I (noon) I (1 pm) I (2 pm)9 11 I (7 am) I (8 am) I (9 am) I (10 am) I (11 am) I (noon) I (1 pm) I (2 pm)

10 12 I (7 am) I (8 am) I (9 am) I (10 am) I (11 am) I (noon) I (1 pm)11 13 I (7 am) I (8 am) I (9 am) I (10 am) I (11 am) I (noon)12 14 I (7 am) I (8 am) I (9 am) I (10 am) I (11 am)13 15 I (7 am) I (8 am) I (9 am) I (10 am)14 16 I (7 am) I (8 am) I (9 am)15 17 I (7 am) I (8 am)16 18 I (7 am)17 19

Di_rule.xls 3/8/99