---

Xq^ is the start value of oxygen analyser reading, expressed as a mole fraction;

x₀₂ is the oxygen analyser reading during test, expressed as a mole fraction;

is the start value of carbon dioxide analyser reading including ambient air content, expressed as a mole fraction;

x_Co₂ is the carbon dioxide analyser reading during the test, expressed as a mole fraction;

x^a_}]_2O is the ambient mole fraction of water vapour (to be calculated according to Equation (A.8)

given in A.3).

NOTE The definition of start value is given in the appropriate part of this standard (see 5.5.3, E.3.2.3 and E.3.3.4).

Equations (A.3) to (A.7) are based on certain approximations leading to the following limitations.

1. The amount of CO generated is not taken into consideration. Normally, the error is negligible. If the concentration of CO is measured, corrections can be calculated for those cases where the influence of incomplete combustion may have to be quantified.

2. The influence of water vapour on measurement of flow and gas analysis is only partially taken into consideration. A correction for this error could be obtained by continuous measurement of the partial water vapour pressure but is not considered necessary for this test.

3. The value of 17,2 x 10³ kJ/m³ for the factor E, is an average value for a large number of products and gives an acceptable accuracy in most cases.

A.3 Calculation of the mole fraction of water vapour in the air

The mole fraction of water vapour in the air can be calculated from the conditions of the atmosphere (ambient temperature, 0_atm, relative humidity, RH, and atmospheric pressure, p°_atm) taken at the start of the test.

The following equation is used for the calculation: where

- ^RH

H₂O 100

1

о
Patm

_e23,2

3816
(0_o;m+273,15)-46

(A.8)

RH is expressed in %;

p°_atm is expressed in Pa;

0atm is expressed ІП °С.Annex В
(normative)

Smoke production

The optical density is represented by the extinction coefficient, k, expressed in reciprocal metres (m'¹), and is defined as follows:

(B.1)

where

J_o is the light intensity for a beam of parallel light rays measured in a smoke free environment with a detector having the same spectral sensitivity as the human eye;

1 is the light intensity for a parallel light beam having traversed a certain length of smoky

environment;

L is the length of beam through smoky environment (optical path length), expressed in

metres.

The instantaneous rate of light-obscuring smoke SPR, expressed in square metres per second (m²/s), and the total amount of smoke TSP expressed in square metres (m²) are then calculated from:

S

(B.2)

(B.3)

PR = kV_s

TSP = j* V_sdt

0

where

V_s is the volume flow in the exhaust duct at actual duct gas temperature, expressed in cubic metres per second (m³/s);

t is the time from ignition of the burner, expressed in seconds (s).

NOTE Negative SPR values indicate I> /„which is not a smoke related phenomenon.Annex C
(informative)

Additional information on Reynolds number in Figure 5

The pressure differences are measured with a sensitive electronic manometer. The uniform low velocity flows are provided by two independent facilities as described in Me Caffrey and Heskestad [5]. A hot wire anemometer and Pitot-static tube, where appropriate, are used to determine the stream velocity. For data reduction via computer, the polynomial curve fit obtained for the points shown in Figure 5 is:

1

I = 1,533-1,366x10~³/?_e

+

(C.1)

1,688x10 ⁶7?_e² -9,706x1 O’¹⁰R³

+ 2,555x10“¹³R_e⁴ - 2,484x1 O'¹⁷R_e⁵

This representation is valid for 40 < R_e < 3 800 and is accurate to about 5 %.

A suitable value of D, the outer diameter of the probe, is 16 mm.Annex D
(normative)

Flow distribution inside the duct

D.1 General

For the calculation of HRR, a velocity profile factor k_c shall be used. This factor shall be determined by measuring the velocity profile both in both the vertical and horizontal direction of the duct. The procedure to determine k_c is specified in D.2.

D.2 Velocity profile factor k_c

D.2.1 General

The k_c factor shall be measured after set-up, maintenance, repair or replacement of the bidirectional probe or other major components of the exhaust system. The measurements shall be made using a Pitot tube, a hot wire anemometer or the bi-directional probe, provided correct positioning can be ensured.

D.2.2 Measurement specifications

1. The equipment shall be run on a damping setting sufficiently high to obtain a steady reading.

2. The duct shall have 4 entry ports, spaced by 90° around the circumference, which are used to introduce the velocity measurement device. When inserted into the duct the measurement probe shall be positioned and fixed mechanically, rather than held by hand.

NOTE 1 It is also possible to measure the gas velocity profile at all measurement positions with a duct having two entry ports which are spaced by 90°.

3. Measurements shall be taken from each port in turn and the entry ports not used shall be closed.

4. At each port the gas velocity shall be measured at each of 5 measurement radius positions, once when traversing the flow measuring device outwards from the centre to the duct wall and once when traversing inwards to the centre. Each velocity measurement shall consist of 10 readings or scans (i.e. a total of 20 readings at each measurement position).

NOTE 2 It is not necessary to note 10 readings or scans for a measurement if an appropriate anemometer which automatically measures and calculates an adequate average value is used.

The radius measurement positions shall be at the following distance from the wall expressed as a fraction of the radius (taken from ISO 3966:2008): 0,038 - 0,153 - 0,305 - 0,434 - 0,722 and 1,000 (centre). The positions for measurement for a 400 mm duct are shown in Figure D.1.

Dimensions in millimetres

Figure D.1 - Section of the exhaust duct - Positions for measurement of the gas velocity

D.2.3 Actions

Perform the following steps.

Set the volume flow of the exhaust to the setting where the velocity profile has to be determined and at a volume flow in the range given in 4.3.

1. Measure the gas velocity in all measurement positions, six positions per entry port.

2. Calculate the gas velocity at all measurement positions as the average of the 20 values measured, giving V_c for the centre position and five V„ values for the five other positions for each entry port.

NOTE As a result, the velocity profile is measured and calculated both horizontally and vertically over the full diameter.

D.2.4 Calculation of k_c

For a given radius the average velocity at a radius n is given by V_N, which is the average of the four V„ values measured. The average velocity at the centre is given by K_r, which is the average of the four V_c values measured. The profile factor k_c is then (1/5) x (V_Nt+ V_N2+ V_N3+ V_N4+ V_NS)/ V_c where V_NJ... V_NS are the average velocities at the 5 radii.D.2.5 Measurement report

The measurement report shall include the following information:

1. the velocity profile based on the average V„ at five radii and K, separately for each entry port (a vertical and a horizontal cross section);

the four values of V„ for each radius, the four values of V_c, the values f^and V_c, and the resulting k_c.Annex E
(normative)

Commissioning calibrations

E.1 General procedures for separate pieces of equipment

Several of the measuring instruments used need regular calibration. As a minimum, the calibrations in this annex shall be performed.

NOTE In this standard it is assumed that the instruments are also maintained and calibrated according to the manufacturers’ specifications.

E.2 Gas analyser calibrations

E.2.1 General

The same gas flow shall be used for calibration and for the test.

E.2.2 Oxygen analyser adjustment

The oxygen analyser shall be adjusted for zero and span each day on which tests are performed. The analyser output for dried ambient air shall be (20,95 ± 0,01) %. A possible procedure to perform the adjustment is given in F.2.1.

E.2.3 Oxygen analyser output noise and drift

E.2.3.1 Noise and drift

Noise and drift of the oxygen analyser output using the data acquisition system shall be checked after set up, maintenance, repair or replacement of the oxygen analyser or other major components of the gas analysis system.

NOTE It is recommended that this check is carried out at least every six months depending on the frequency of use of the equipment.

E.2.3.2 Actions

1. Feed the oxygen analyser with oxygen-free nitrogen gas, until the analyser reaches equilibrium.

2. After at least 5 min in oxygen-free conditions, adjust the volume flow in the exhaust duct to (1,00 ±0,05) m³/s and switch to air from the exhaust duct with the same flow rate, pressure and drying procedure as for sample gases. When the analyser reaches equilibrium, adjust the analyser output to (20,95 ± 0,01) %.

3. Within 1 min, start recording the oxygen analyser output at 3 s interval for a period of 30 min.

4. Determine the drift by use of the least squares fitting procedure to fit a straight line through the data points. The absolute value of the difference between reading at 0 min and at 30 min of this linear trend line represents the drift.

5. Determine the noise by computing the root-mean-square deviation around the linear trend line. NOTE Root-mean-square deviation (RMSD) is defined as: J" Л

ТЛУ’-У'У
m

n where = measured value;

у і = estimated/predicted value by linear trend line; n = total number of measurements.

E.2.3.3 Criteria

The sum of drift and noise (both taken as positive values) shall be not more than 0,01 % of the (K_o/K_a,_r) value.

E.2.3.4 Calibration report

The calibration report shall include the following information:

1. the graphs of O₂ (t) in % Г₀/Г_а,_г;

2. the noise and drift values calculated according to E.2.3.2 d) and e) and expressed as percentages of the V₀JV_air value.

E.2.4 Carbon dioxide analyser adjustment

The carbon dioxide analyser shall be adjusted for zero and span each day on which tests are performed. The analyser output shall be within 0,1 % (И_СОг/ И_а,_г) of the calibration gases used. The analyser output for carbon dioxide-free nitrogen gas shall be (0,00 ± 0,02) %. A possible procedure to perform the adjustment is given in F.2.2.

E.3 HRR calibrations

E.3.1 General

The calibration shall be performed both by means of burners and liquids.

E.3.2 HRR calibration by means of the burner defined in EN 60332-3-10

E.3.2.1 Conditions

1. Burner levels : 20,5 kW to 30,0 kW and 40 kW to 50 kW;

2. Ratio air/gas: settings from standard ignition source (for 40 kW to 50 kW the use of 1 or 2 burners is allowed);

3. Burner gas and air flow measurement: by means of mass flow or rotameter;

NOTE Mass flow meters are recommended.

On line measurement of gas consumption by means of mass loss measurement.E.3.2.2 Procedure

Perform the following steps with the measuring equipment operating, with the airflow into the chamber set to (8 000 ± 400) l/min and the door closed.

1. Set the volume flow of the exhaust to: V298 = (1,00 ± 0,05) m³/s.

2. Record the temperature in the exhaust duct and the ambient temperature for at least 300 s. The temperatures in the duct shall not differ by more than 4 К from the ambient temperature.

3. Start the time measurement and the automatic recording of data: t = 0 s, by definition.

4. Ignite the burner and adjust the propane mass flow according to Table E.1 within the first 5 s of each

step.

Table E.1 - Burner ignition times and HRR levels

5. Stop the automatic recording of data at the end of step 3.

E.3.2.3 Calculations

Calculate the following parameters using the k_c value obtained from the flow profile determinations for the commissioning A, factor and using the correct E-value for propane (16,8 MJ/m³):

1. the average HRR of burner between 540 s and 840 s;

2. the THR during the calibration test;

3. the mass loss of propane by means of weighing the gas bottle;

4. the start value of oxygen %, light intensity and HRR as the average during the first 60 s of the 300 s

base line period;

5. the end value of oxygen %, light intensity and HRR as the average during the last 60 s of the calibration test;

6. the difference between the start and end values of oxygen %, HRR and light intensity.

E.3.2.4 Criteria

The following criteria shall be met:

1. the average HRR of burner between 540 s and 840 s shall be within 10 % of the set value;

2. the THR measured during the calibration test shall not differ by more than 10 % from the total heat

release value determined from the mass loss measurement using the effective heat of combustion of propane (46,4 kJ/g). The error from this calculation (C,) shall be used in the determination of the commissioning factor, A_t;

3. the difference between the start and end of test values for oxygen %, HRR and light intensity shall meet the requirements in 5.5.4.

E.3.3 HRR calibration by means of burning a flammable liquid

E.3.3.1 General

In addition to propane burns, calibration by burning a given mass of liquid in a tray shall be conducted in order to

1. compare the two kinds of calibration,

2. reach higher heat release levels, at least for short periods.

As an example, a procedure for methanol is given.

E.3.3.2 Conditions to be used for burning methanol

1. Combustible: methanol (99,5 % purity).

2. Tray area: area of approximately 0,4 m².

NOTE 1 The use of a circular tray is recommended.

3. Mass of combustible: (3 200 ± 25) g

4. Total mass loss measurement by measuring mass before and after test.

NOTE 2 The volume of methanol and tray area were chosen from the results of previous experiences as a compromise between the need to get a high enough peak HRR (approximately 150 kW) without jeopardising the chamber by releasing too much energy.

E.3.3.3 Procedure for methanol

Perform the following steps with the measuring equipment operating, with the airflow into the chamber set to (8 000 ± 400) l/min and the door closed during the burn:

1. set the volume flow of the exhaust to: V298 = (1,00 ± 0,05) m³/s;

2. record the temperature in the exhaust duct and the ambient temperature for at least 300 s. The temperature in the duct shall not differ more than 4 °С from the ambient temperature;

3. start the time measurement and the automatic recording of data where the start time is defined as t - 0 s;

4. weigh the amount of methanol to be used and pour it into the container at t = 240 s;

5. ignite the liquid at t = 300 s;

NOTE Care should be taken when working with burning liquids.

6. after extinction of the burning liquid wait for another 300 s;

7. stop the automatic recording of data after this 300 s period.

E.3.3.4 Calculations

Calculate the following parameters using the k_c value obtained from the flow profile determinations for the commissioning k, factor and using the correct E-value for methanol (17,47 MJ/m³):

1. the THR (total heat release) during the calibration test;

2. the corresponding total heat release by using the mass loss of methanol;

3. the start value of oxygen %, light intensity and HRR as the average during the period 60 s to 120 s of the 300 s base line period.

4. the end value of oxygen %, light intensity and HRR as the average during the last 60 s of the calibration test i.e. during the last 60 s of the 300 s after the pool fire has extinguished;

5. the difference between the start and the end values of oxygen %, HRR and light intensity.

E.3.3.5 Criteria

The following criteria shall be met:

1. the THR (total heat release) measured during the calibration test shall not differ by more than 10 % from the total heat release value determined with the mass loss measurement using the effective heat of combustion of methanol of 19,94 kJ/g. The error from this calculation shall be used in the determination of the commissioning factor, A_t;

2. the difference between the start and the end of test values for oxygen %, HRR and light intensity shall meet the requirements in 5.5.4.

E.3.4 Commissioning factor A_t used for HRR calculations

A final commissioning k, factor shall be determined after performing these calibrations with propane and liquid fuels as described in this annex. For this a correction factor is determined for both the propane and liquid fuel calibrations. This correction factor is determined as the THR calculated by means of the mass loss of propane or liquid divided by the THR measured by the HHR measurement system. The final к, factor is the k_c factor determined in D.2 multiplied by the average of the correction factors from the propane (C_p) and methanol (C_m) calibrations.

However the final k, factor used for the calculation of the heat release rate shall not differ by more than 10 % of the ^ factor determined in D.2. If the figure of 10 % is exceeded, then improvement of the velocity profile and/or troubleshooting shall be performed.

An example of this procedure is given below.

Assume that the k_c factor that was determined with the procedure in Annex D is equal to 0,9. The laboratory performs HRR calibrations at 20,5 kW, 30,0 kW and 40 kW to 50 kW with errors on THR of 3 %, 2,5 % and -1,5 % resulting in an average correction factor for propane of 1,3 %. Then a methanol calibration results in a THR error of 6 %. The overall average is thus 3,7 %. The final commissioning k, is then 0,93. Table E.2 and Figure E.1 give an overview of the procedure.

Table E.2 - Example of determination of commissioning k, factor