ASTM D6277 Method for Determination of Benzene in Spark-Ignition Engine Fuels
ASTM D6277 Standard Test Method for Determination of Benzene in Spark-Ignition Engine Fuels Using Mid Infrared Spectroscopy
10. Calibration and Qualification of the Apparatus
10.1 Before use, the instrument must be calibrated according to the procedure described in Annex A1. This calibration can be performed by the instrument manufacturer prior to delivery of the instrument to the end user. If, after maintenance, the instrument calibration is repeated, the qualification procedure must also be repeated.
10.2 Before use, the instrument must be qualified according to the procedure described in Annex A1. The qualification need only be carried out when the instrument is initially put into operation, recalibrated, or repaired.
11. Quality Control Checks
11.1 Confirm the calibration of the instrument each day it is used by measuring the benzene concentration using the procedure outlined in Section 12 on at least one quality control sample of known benzene content. The preparation of known benzene concentration is described in 11.1.1 and 11.1.2.
11.1.1 Standard(s) of known benzene concentration shall be made up by mass according to A1.1 and converted to volume % using the measured density as outlined in Section 13. At least one standard shall be made up at 1.2 (±0.2) mass % benzene, that is, nominally 1.0 volume %. Additional standards may also be prepared and used for quality control checks.
11.1.2 Standard(s) should be prepared in sufficient volume to allow for a minimum of 30 quality control measurements to be made on one batch of material. Package or store, or both, quality control samples to ensure that all analyses of quality control samples from a given lot are performed on essentially identical material.
11.2 If the benzene volume % value estimated for the quality control sample prepared at 1.2 mass % benzene differs from the known value by more than 0.12 volume %, then the measurement system is out-of-control and cannot be used to estimate benzene concentrations until the cause of the out-of-control behavior is identified and corrected.
11.3 If correction of out-of-control behavior requires repair to the instrument or recalibration of the instrument, the qualification of instrument performance described in A1.3 shall be performed before the system is used to measure benzene content on samples.
