Document ID: chunk:federal_register_of_legislation:F2023L00129:reg:10:p85
Version: federal_register_of_legislation:F2023L00129
Segment Type: reg
Provision Reference: reg 10 (pt 85/150)
Character Range: 964375–967358

Numeratorm / Denominatorm
3.2. "Numerator"
 The numerator of a specific monitor m (Numeratorm) is a counter indicating the number of times a vehicle has been operated such that all monitoring conditions necessary for that specific monitor to detect a malfunction have been encountered.
3.3. "Denominator"
 The denominator of a specific monitor m (Denominatorm) is a counter indicating the number of vehicle driving events, taking into account conditions specific to that specific monitor.
3.4. "General Denominator"
 The general denominator is a counter indicating the number of times a vehicle has been operated, taking into account general conditions.
3.5. Abbreviations
 IUPR In-Use Performance Ratio
 IUPRm In-Use Performance Ratio of a specific monitor m
4.  General requirements
 The OBD system shall have the capability of tracking and recording in-use performance data (paragraph 6.) of the OBD monitors specified in this paragraph, of storing these data in computer memory and communicating them off-board upon request (paragraph 7.).
 The in-use performance data of a monitor consists of the numerator and denominator enabling the calculation of the IUPR.
4.1. IUPR monitors
4.1.1. Groups of monitors
 Manufacturers shall implement software algorithms in the OBD system to individually track and report in-use performance data of the groups of monitors mentioned in Appendix 1 to this annex.
 Manufacturers are not required to implement software algorithms in the OBD system to individually track and report in-use performance data of monitors running continuously as defined in paragraph 4.2.3. of Annex 9B to this Regulation.
4.1.2. Multiple monitors
 For each group of monitors which are required to be reported by paragraph 4.1.1., the OBD system shall separately track in-use performance data, as specified in paragraph 6., for each of the specific monitors belonging to that group.
4.2. Limitation of the use of in-use performance data
 In-use performance data of a single vehicle are used for the statistical evaluation of the in-use performance of the OBD system of a larger group of vehicles.
 Contrary to other OBD data, in-use performance data cannot be used to draw conclusions concerning the road-worthiness of an individual vehicle.
5.  Requirements for calculating in-use performance ratios
5.1. Calculation of the in-use performance ratio
 For each monitor m considered in the present annex, the in-use performance ratio is calculated with the following formula:
 IUPRm = Numeratorm / Denominatorm
 Where the Numeratorm and Denominatorm are incremented according to the specifications of this paragraph.
       5.1.1.  Requirements for the ratio when calculated and stored by system
 Each IUPRm ratio shall have a minimum value of zero and a maximum value of 7.99527 with a resolution of 0.000122[44].
 A ratio for a specific component shall be considered to be zero whenever the corresponding numerator is equal to zero and the corresponding denominator is