ASTM D6201 Dynamometer Evaluation of Unleaded Spark-Ignition Engine Fuel
ASTM D6201 Standard Test Method for Dynamometer Evaluation of Unleaded Spark-Ignition Engine Fuel for Intake Valve Deposit Formation
11. Calibration
11.1 Test Standard Calibration:
11.1.1 Verification:
11.1.1.1 Verify the calibration of test stands with reference fuel tests scheduled by the TMC. Stand calibration tests are normally conducted upon expiration of the 180 day calibration time period. However, calibration time periods may be adjusted by the TMC. Any deviation from the standard calibration time frequency shall be approved by the TMC and reported on a supplemental operational data sheet of the final test report. Any non-reference test started within 180 days of the completion date of the previous calibration test is considered within the calibration time period.
11.1.1.2 Containers of reference fuel additive are provided by the TMC for each stand calibration test. Each container has the correct amount of reference fuel additive to blend with 300 gal of the IVD Reference Base fuel.
11.1.2 Unacceptable Calibration Results:
11.1.2.1 It is recognized that a certain percentage of calibration tests will fall outside the acceptance limits because of the application of statistics in the development of the acceptance limits. Failure of a reference fuel test to meet Shewhart or EWMA precision control chart limits can be indicative of a false alarm or a stand or industry problem. When this occurs, the laboratory, in conjunction with the TMC, shall attempt to determine the problem source. The TMC may solicit input from industry expertise (other testing laboratories, the test sponsor, ASTM Technical Guidance Committee, IVD Dynamometer Test Surveillance Panel, IVD Dynamometer Test Operations and Hardware Subpanel, and so forth) to help determine the cause and extent of a problem. Industry problems shall be adjudicated by the IVD Dynamometer Test Surveillance Panel.
11.1.2.2 If the TMC determines the problem is a false alarm, and is stand related, there is no impact on non-reference tests running in other stands within the laboratory.
11.1.2.3 The TMC will reschedule a calibration test once it is satisfied that no particular problem exists or the problem has been resolved. The laboratory shall provide adequate documentation to support the conclusions reached during this process. This documentation shall be attached to the acceptable calibration test report. It shall provide sufficient information to show how the problem related to other tests operated during the same period of time.
11.1.3 Test Stand Modifications - Report modification of test stand control systems or completion of any nonstandard test on a calibrated stand to the TMC immediately. A nonstandard test includes any test completed under a modified procedure requiring hardware or controller tuning modifications to the test stand. The TMC will determine whether another calibration test is necessary after the modifications have been completed.
11.1.4 Reference Fuel Accountability:
11.1.4.1 Laboratories conducting calibration tests are required to provide a full accounting of the identification and quantities of all reference fuels used.
11.1.4.2 With the exception of the new fuel analysis required in 9.2, no physical or chemical analysis of new reference fuels shall be performed without permission of the TMC. Retain all reference fuel samples for 90 days.
11.1.5 Test Numbering System:
11.1.5.1 Acceptable Tests - The test number shall follow the format AA-BB-CCC, where AA represents the stand number, BB represents the number of tests since the last reference, and CCC represents the total number of tests on the stand.
As an example, 02-15-125 represents the 125th test on Stand No. 2 and the 15th test since the last reference. Consecutively number all tests on a given stand.
11.1.5.2 Unacceptable or Aborted Tests - If a calibration test is aborted or the results are outside the acceptance limits, the CCC portion of the test number for subsequent calibration test(s) shall include a letter suffix. The suffix shall begin with the letter A and continue alphabetically until a calibration test is completed within the acceptance limits. For example, if three consecutive unacceptable calibration tests are completed on the same test stand, and the test number of the first test is 02-0-125, the next two test numbers would be 02-0-125A and 02-0-125 B. If the results of the next calibration test are acceptable, the test number 02-0-125C would permanently identify the test and appear on future correspondence. The completion of any amount of operational time on tests other than calibration tests will cause the test number to be increased by one. No letter suffix will be added to the test number of tests other than calibration tests.
11.2 Instrumentation Calibration - Calibrate the instrumentation described below once every four tests or six weeks, which ever comes first, or as otherwise indicated.
11.2.1 Engine Load Measurement System - Calibrate the load measurement system once every four tests or six weeks, which ever comes first. Calibrate over the operating range of the test.
11.2.2 Engine Speed Measurement System - Calibrate the speed measurement system once every four tests or six weeks, which ever comes first. Calibrate over the operating range of the test.
11.2.3 Engine Manifold Absolute Pressure Measurement System - Calibrate the manifold absolute pressure measurement system once every four tests or six weeks, which ever comes first. Calibrate over the operating range of the test.
11.2.4 Engine Fuel Consumption Measurement System - Calibrate the fuel consumption measurement system once every four tests or six weeks, which ever comes first. Calibrate over the operating range of the test.
11.2.5 Engine "Real Time" Equivalence Ratio Measurement System - It is recommended that a real time equivalence ratio measurement system be utilized with this test. One example of a typical system is the HORIBA Model MEXA 101. The system utilizes an extended range exhaust gas oxygen sensor (UEGO) air-fuel sensor that is inserted into the exhaust gas stream. The instrument gives instantaneous equivalence ratio measurements. One advantage of the system is its ability to detect when the test is not operating at normal equivalence ratio conditions (usually representing an engine problem). It allows for the problem to be addressed as it occurs. Calibrate the equivalence ratio measurement system once every four tests or six weeks, whichever comes first.
11.2.6 Exhaust Gas Analysis Calibration - If exhaust gas analysis equipment is used, calibrate the exhaust gas analysis equipment before each set of measurements are taken during the test. The calibration technique should compensate for the flow rate sensitivity of the exhaust gas analysis meters.
11.2.7 Pressure and Temperature Probe Measurement Systems - Calibrate the pressure and temperature probe measurement systems used to acquire the pressure and temperature data detailed in Table 1 every four tests or six weeks, which ever comes first. Calibrate over the operating range of the test.
