BS ISO 7210:2018 pdf download – Routine analytical cigarette-smoking machine — Additional test methods for machine verification
5.2.2 System A
The signal delivered by the pressure transducer is linearized by appropriate circuits and transmitted to an integrator and a recording apparatus.
The system can record a picture of the puff profile and measure its volume.
5.2.3 System B
This system uses digital conversion and a computer to produce the same information as it is given by system A.
5.2.4 Requirements for both systems
The device shall not increase the pressure drop of the system above the limit of 300 Pa and the overall gain and response of the system shall be sufficient to visualize the puff profile and determine its significant parameters.
A sufficient result will be achieved by the use of elements that fulfil the following conditions:
— laminar flow element with a nominal pressure drop of 100 Pa ± 10 Pa at a flow of 17, 5 ml/s;
— pressure transducer with a suitable range, an accuracy of ± 5 Pa or better and a minimal response frequency of 1 kHz.
The above apparatus provides the means to obtain flow rate and time profiles for puffing as shown in ISO 3308 and ISO 20778.
NOTE Measurement of puff volume, by either system A or system B, can only be a secondary measurement following calibration by reference to a primary device such as a soap film burette as described in Clause 7.
5.2.5 Expression of results
The following results need to be reported:
— total drawn puff volume, in ml;
— maximum flow rate, in ml/s;
— time between starting and reaching the maximum flow rate, in s;
— volume drawn after the time the puffing source ceases to apply suction, in ml;
— total puff duration time, in s.
The target values for the above parameters shall be those specified in ISO 3308 and ISO 20778.
6 Verification of restricted smoking
Measurement of the volume of the smoulder stream smoke between two puffs for machines of discontinuous function or between two suction strokes for machines of continuous function.
For smoking machines with permanent connection of the port to the suction device, this test is not necessary.
Apparatus permitting an assembly as shown in Figure 3, so that:
— the length of a soap film bubble flowmeter does not exceed 12 cm;
— there is close contact between the smoke port or the cigarette holder, the soap film bubble flowmeter and the cigarette.
Smoke the first half of a cigarette without using the test unit. Introduce and adjust a soap bubble in the soap film bubble flowmeter as described in the supplier’s manual. Connect the test unit to the smoke port or cigarette holder and insert the cigarette into it. Carry out the test during smouldering of the second half of the total length of the cigarette. On linear machines the test should be performed for at least one minute. On rotary machines it should be performed over a full rotation.
6.4 Expression of results
Note the flow rate of the smoulder stream smoke, in millilitres per minute, for each channel of the smoking machine. The result shall not exceed 1 ml/min.
7 Soap film bubble flowmeter for the determination of the puff volume
This clause describes the apparatus of a soap film bubble flowmeter used for the determination of the puff volume as specified in ISO 4387 and ISO 20779.
The burette is moistened with wetting agent solution and connected to the smoking position of the smoking machine. A lamella (bubble) is generated and adjusted to the zero-mark of the burette. Upon release of a puff, the bubble is displaced by the puff volume of the smoking machine and thus indicates the actual puff volume amount. Figure 4 shows the principal design of a soap film bubble flowmeter.BS ISO 7210 pdf download.