How to make the Pressure Drop for the cigarette filter rod?

Making PD measurements
The exact procedure for measuring the PD of samples will depend not only on the type of sample to be measured but also on the type of instrument used. There are a number of points, however, that need to be checked for all PD measurements:
▪   The  instrument  used  should  be  suitable  for  the  type  of product  to  be  measured. Generally, the type of sample holder and measurement head device is different for filter  rods  and  cigarettes  due  to  their  different  construction  and  measurement requirements.
o Filter rods should be completely encapsulated in an impermeable sleeve to prevent air ‘short-circuiting’ down the outside of the filter
o Cigarettes require that the butt end of the sample only is encapsulated by the sample holder [2].
▪   The  instrument  should be  adjusted  correctly  for the  sample  to be measured with reference to the manufacturer’s instructions.
o Ventilated cigarettes require that the centre seal is located correctly so that values  of  PDO  and  PDC  are  correctly  measured  (particularly  that  the ventilation inlets are not blocked).

o For both cigarettes and filter rods, the correct size of seals/sleeve should be fitted to avoid leakage or crushing of the sample. As a guide, the following sizes are recommended:
o Cigarettes:
Consult  instrument  instructions;  typically  several  sleeve  sizes  are available to  cover the  full  diameter range  of products  that includes ultra/micro slims (~4.7.mm), super slims (~5.2 mm), slims (~7 mm), conventional king size (~7.9 mm) and magnums (up to ~9 mm).
o Cured filter rod:
Sleeve inside diameter = (rod diameter – 0.1 mm) to (rod diameter – 1.0 mm)
o Uncured filter rods:
Sleeve inside diameter = (rod diameter – 0.1 mm) to (rod diameter – 0.6 mm)
▪   Samples should be in equilibrium with the measurement environment to avoid errors due to moisture and temperature changes within the sample during the measurement.
▪   Samples should be handled carefully and as little as possible to avoid damage and changes of sample moisture and temperature.
▪   Calibration should be made frequently enough to avoid errors in measurement due to PD changes with ambient conditions. The changes in measured PD value with changes in ambient conditions are given in [3]. For guidance, calibration is recommended if:
o Ambient temperature has changed by more than 2 °C
o Ambient moisture level has changed by more than 20 % RH
o Ambient pressure has changed by more than 50 mbar