Isokinetic Sampling Train M9096

Metric Calculations
Profile Version
Variables Used In Calculations
Ps

Absolute Stack Pressure, mbar

Pb

Barometric Pressure, mbar

Pstatic

Static Pressure, mbar

Md

Dry Molecular Weight of the Stack Gas

%CO2

Carbon Dioxide Content in Gas as a Percentage, %

%O2

Oxygen Content in Gas as a Percentage, %

%N2

Nitrogen Content in Gas as a Percentage, %

CO(ppm)

=
=

Carbon Monoxide Content in Gas, ppm

Percentage of Water Vapour in the Gas Stream on a Volume/Volume Basis

Ms

Molecular Weight of the Stack Gas on a Wet Basis

Vmc

Volume of Gas Pulled Through the Meter at STP, m3

Vwc
VH2O

Volume of Water as a Gas Condensed from the Stack Gases when Vmc (m3) of Gas is Pulled Through the Meter, m3

=
=

Volume of Condensed Water Collected in a Moisture Test, mL or g

22.414/(18 x 1000) (Molar Gas Volume at STP and Molecular Weight of Water (18))

Nozzle Diameter, mm

Qm

Pm

Ideal Flow Rate Through the Sample Train (l min-1)

Pressure in the Gas Meter (in Simple Systems this is the Barometric Pressure Pb), mbar

Tm

Absolute Temperature of the Gas Meter (in Simple Systems this is the Ambient Air Temperature Close to the Meter ( Tamb oC + 273), K

Bwm

Percentage of Water Vapour in the Gas Meter on a Volume/Volume Basis, Assumed to be Zero as Most Gas Meters are After the Drying System, %

Cp

Pitot Tube Coefficient (S-Type = 0.84; Ellipsoidal Type = 1), Ideally Should Be a Calibrated Tip and This Value Used

Bws
Bws

0.001245
Dn

Percentage of Water Vapour Present on a Volume/Volume Basis

Isokinetic Sampling Train M9096

Variable

Page 1 of 12

Ts
P

=
=

Absolute Temperature of the Stack Gases (Average Stack Temp. oC + 273), K

Differential Pressure of the Velocity Head as Measured by the Pitot Tube, mbar

Isokinetic Sampling Train M9096

Variable

Page 2 of 12

Isokinetic Sampling Train M9096

Metric Calculations
Profile Version
Variables Used In Calculations
As

Cross-Sectional Area of the Stack (m2)

i.e. (P)avg= (Average (P1 + P2 + P3 + etc).))2 in Many Cases the Simple Average Will Suffice

Vmc

Volume of Gas Pulled Through the Meter at STP and on a Dry Gas Basis, m3

Vm
Yd

Volume of Gas Pulled Through the Meter as Recorded by the Meter, m3

Gas Meter Calibration Factor to Account for Calibration of Meter Usually Yd = 1

0.2695

=
=

Correction Factor to STP = 273/1013

Density of Gas at Pressure P (Pa) and Temp T (K)

Boltzmann Gas Constant 8.31432 X 103 Nm kmol-1.K-1

Molecular Weight of the Specific Gases

Qa

Actual Flow of Gases in Duct at Stack Gas Conditions of Temperature and Pressure, m3

Qstd
Cstd

Actual Flow of Gases in Duct at STP, m3

Measured Concentration in the Stack Gases at STP and on a Dry Gas Basis, mg Nm-3

Ds

Total Amount of Dust Collected Including Washings, mg

Es
q
I(%)

=
=
=

Emission Rate from the Stack, kg hr-1

Time Pump was Running and Gas Being Sampled, min
Isokinicity, %

Qm

Flow Through the Meter at Meter Conditions, l min-1

Isokinetic Sampling Train M9096

Variable

Page 3 of 12

Isokinetic Sampling Train M9096

Metric Calculations
Profile Version
Conversion of Units
Pressure
Pressure is measured in a variety of unit and as a result often leads to confusion, the following are useful inter-conversions:
1 mbar
= 10.2 mmH2O
1 mbar

1 hpa

1 mbar

0.75006 mmHg

1 mbar

100 Pa

1013.25 mbar
13.6 mmH2O

760 mmHg

1 mmHg

1 mmH2O

0.09807 mbar

10332.3 mmH2O

760 mmHg

1 mmH2O

9.81 Pa

1 Pa

1 Nm (N is a Newton in this case Normal as used elsewhere)

101325 Pa

760 mmHg

1 mmHg

1.33322 mbar

Temperature
In this equation is always assumed to be in absolute units
Absolute Temp

Temperature in Celcius + 273 K

Isokinetic Sampling Train M9096

Variable

Page 4 of 12

Isokinetic Sampling Train M9096

Variable

Page 5 of 12

Isokinetik Flowrate Calculation

M9096 Isokinetic Flowrate Calculation

S-212352-1
Element

Value

Unit

Stack Temperature

571.70 deg C

Stack Pressure

101.33 kPa (gauge)

Available
Nozzles

Selected

Calculated

3.0 mm

Nozzle

Flowrate

4.5

Stack Velocity

11.12 m/sec

4.5 mm

Console Temperature

20.00 deg C

6.0 mm

Absolute Pressure

101.32 kPa (absolute)

Nozzle Area

15.9043

Condition Factor

0.3470

Calculated Flow

3.6824

3.68

l / min

7.5 mm

M9096 Isokinetic Flowrate Calculation

S-212352-2
Element

Value

Unit

Stack Temperature

610.27 deg C

Stack Pressure

101.31 kPa (gauge)

Available
Nozzles

Selected

Calculated

3.0 mm

Nozzle

Flowrate

4.5

Stack Velocity

11.19 m/sec

4.5 mm

Console Temperature

20.00 deg C

6.0 mm

Absolute Pressure

101.32 kPa (absolute)

Nozzle Area

15.9043

Condition Factor

0.3318

Calculated Flow

3.5428

7.5 mm

Page 6

3.54

l / min

Isokinetik Flowrate Calculation

M9096 Isokinetic Flowrate Calculation

S-212352-3
Element

Value

Unit

Stack Temperature

612.18 deg C

Stack Pressure

101.33 kPa (gauge)

Available
Nozzles

Selected

Calculated

3.0 mm

Nozzle

Flowrate

4.5

Stack Velocity

11.37 m/sec

4.5 mm

Console Temperature

20.00 deg C

6.0 mm

Absolute Pressure

101.32 kPa (absolute)

Nozzle Area

15.9043

Condition Factor

0.3311

Calculated Flow

3.5929

3.59

l / min

7.5 mm

M9096 Isokinetic Flowrate Calculation

Element

Value

Unit

Stack Temperature

121.00 deg C

Stack Pressure

101.31 kPa (gauge)

Stack Velocity
Console Temperature
Absolute Pressure

Available
Selected

Calculated

3.0 mm

Nozzle

Flowrate

12 m/sec

4.5 mm

4.5

20.00 deg C

6.0 mm

101.32 kPa (absolute)

Nozzle Area

15.9043

Condition Factor

0.7437

Calculated Flow

8.5156

Nozzles

7.5 mm

Page 7

8.52

l / min

Isokinetic Sampling Train M9096

Metric Calculations
Profile Version
Calculations
JENV No.
Sample ID.
Sampling Data:
Pb
Pstatic
% CO2
% O2
% N2

=
= Incinerator

CO (ppm)
Bws
Dn
Qm
Pm
Tm
Bwm

=
=
=
=
=
=
=
=
=
=
=
=

Cp
Ts
DP

=
=
=

1013.00 mbar
0.49 mbar
6.60 %
9.10 %
79.00 %
1.0000 ppm
3.00 %
To be Determined (mm)
3.68 Ideal flowrate through the sample train (l min-1)
1013.00 (In sample systems this is the barometric pressure Pb, mbar)
293.00 K
0.00 Percentage of water vapour in the gas meter on a volume/volume basis, assumed to be zero as most of gas
meters are after drying system, %
0.84
844.70 K
1.91 mbar

Absolute Pressure of the Stack Gas:

Ps

mbar
1013.49 mbar

Molecular Weight of Dry Gas Stream:

Md

27.9360

Molecular Weight of Stack Gas (Wet):

Ms

27.6379

Molecular Weight of Stack Gas (Wet):

D n =|
Dn

const .Q m Pm 100B wm
T mC p
=

100B ws

T sM s
Ps ( P )avg

2.9886 mm

The ideal flowrate Qm is 1 m3 per hour which is 3.68 l min-1 in this example it can be any rate within the capacity of the system being used.
Pm = Pb = Barometric Pressure and Tm is the ambient air temp in the vicinity of the gas meter.
It is unlikely that a 3.01 mm nozzle would be available so it is usual practice to choose the nearest size available. It is safest to chose the slightly
smaller nozzle than calculated as this will ensure that there is sufficient capacity to sample all the sample points. In this case we would chose the 3
mm nozzle rather than the 4.5 mm nozzle also available. However this will also result in a slightly smaller sample of gas being obtained.
Isokinetic Sampling Train M9096

Calculations

Page 8 of 12

It is unlikely that a 3.01 mm nozzle would be available so it is usual practice to choose the nearest size available. It is safest to chose the slightly
smaller nozzle than calculated as this will ensure that there is sufficient capacity to sample all the sample points. In this case we would chose the 3
mm nozzle rather than the 4.5 mm nozzle also available. However this will also result in a slightly smaller sample of gas being obtained.

Isokinetic Sampling Train M9096

Calculations

Page 9 of 12

Setting the Flow Rate of the Sampler:

The flow setting is similar to determining the Isokinicity. We need to set Vs = Vn, i.e velocity in the stack is equal to the velocity entering the nozzle.

10.3108 l min-1

Determination of Particulate Sampling Results:

VH2O
Dn
Pm
Tm
Cp
Ts
DP
As
Vm
Yd

Ds

=
=
=
=
=
=
=
=
=
=
=
=

35.0000
3.00
1013.00
293.00
0.84
844.70
1.91
0.5029
0.200
0.3470
30
1.05

ml or g
mm
mbar
K
Pitot tube coeficient (S-Type)
K
mbar
m2 (Cross-sectional Area of the Stack)
m3 (Volume of Gas Pulled through the meter as recorded by the meter)
Gas Meter Calibration Factor to account for calibration meter
min (Time Pump was running and gas being sampled)
mg (Total amount of Dust Collected including washing)

Water Vapour in Stack:

0.0436 m3

Volume of Gas Sampled at Standard Condition:

At 273 K, 101.325 kPa the Corrected Volume of gas drawn by the gas meter will be:

0.0647 m3 (Volume of Gas Pulled through the meter at STP and on a dry gas basis)

0.4026 %

Velocity of Stack Gases:

25.9960 m s-1

Flow of Gases in the Duct:

784.335 m3 min-1

Isokinetic Sampling Train M9096

Calculations

Page 10 of 12

Flow at Dry Standard Conditions:

151.5184 m3 min-1

Particulate Concentration at STP and on a Dry Gas Basis:

16.2370 mg Nm-3 (Particulate Concentration at 273 K, 101.325 kPa and on a dry gas basis)

Particulate Emission Rate:

0.0738 kg hr-1

Particulate Concentration at STP and on a dry gas basis at 10 % O2:

14.9985 mg Nm-3

Percentage Isokinicity:

101.17 %

Isokinetic Sampling Train M9096

Calculations

Page 11 of 12

Worksheet Analysis

Dust Particulate
Gravimetric
Analyst
Signature

Sample ID.
S-140641

Notes :

Date
:

JENV NO.

Initial Weight

Final Weight

Dust Weight

DGM Initial

DGM Final

Air Volume

Result Dust

Final Result

(gram)

(gram)

(mg)

(liter)

(liter)

(Nm )

(mg/Nm )

(mg/Nm3)

0.1509

0.1520

1.1

Supervisor
Date

:
:

Signature