Betekenis van:
proportional sampling

proportional sampling
Zelfstandig naamwoord
    • the population is divided into subpopulations (strata) and random samples are taken of each stratum

    Synoniemen

    Hyperoniemen


    Voorbeeldzinnen

    1. A heat exchanger HE or electronic flow compensation EFC may be used for proportional particulate sampling and for flow determination.
    2. A bag sampling system may be used to collect a proportional sample of the air withdrawn from and admitted to the enclosure.
    3. The isokinetic sampling probe must be installed facing upstream on the exhaust pipe centreline where the flow conditions in paragraph EP are met, and designed to provide a proportional sample of the raw exhaust gas.
    4. The isokinetic sampling probe must be installed facing upstream on the exhaust pipe centreline where the flow conditions in section EP are met, and designed to provide a proportional sample of the raw exhaust gas.
    5. If flow compensation (i.e., proportional control of sample flow) is used, it must be demonstrated that the ratio of main tunnel flow to particulate sample flow does not change by more than ±2,5 per cent of its set value (except for the first 10 seconds of sampling).
    6. If flow compensation (i.e., proportional control of sample flow) is used, it must be demonstrated that the ratio of main tunnel flow to particulate sample flow does not change by more than ± 5 per cent of its set value (except for the first 10 seconds of sampling).
    7. If the temperature at the inlet to either the PDP or CFV is not kept within the limits stated above, a flow compensation system is required for continuous measurement of the flow rate and control of the proportional sampling in the particulate system.
    8. If the temperature at the inlet to either the PDP or CFV or SSV is not kept within the limits stated above, a flow compensation system is required for continuous measurement of the flow rate and control of the proportional sampling in the particulate system.
    9. If flow compensation (i.e., proportional control of sample flow) is used, it must be demonstrated that the ratio of main tunnel flow to particulate sample flow does not change by more than ± 5 % of its set value (except for the first 10 seconds of sampling).
    10. If it is not possible to compensate for variations in the flow rate provision shall be made for a heat exchanger and a temperature control device as specified in paragraph 2.3.3.1 so as to ensure that the flow rate in the system is constant and the sampling rate accordingly proportional.