(a) Overview. This section describes the overall process for verifying and calibrating the performance of chassis dynamometers.
(b) Scope and frequency. The following table summarizes the required and recommended calibrations and verifications described in this subpart and indicates when they must occur:
Table 1 of Sec. 1066.215--Summary of Required Dynamometer
Verifications------------------------------------------------------------------------
Type of verification Minimum frequency \a\------------------------------------------------------------------------Sec. 1066.220: Linearity Speed: Upon initial installation, within
verification. 370 days before testing, and after major
maintenance. Torque (load): Upon initial
installation and after major
maintenance.Sec. 1066.225: Roll runout Upon initial installation and after major
and diameter verification. maintenance.Sec. 1066.230: Time Upon initial installation and after major
verification. maintenance.Sec. 1066.235: Speed Upon initial installation, within 370
measurement verification. days before testing, and after major
maintenance.Sec. 1066.240: Torque Upon initial installation, within 7 days
(load) transducer of testing, and after major maintenance.
verification.Sec. 1066.245: Response Upon initial installation, within 370
time verification. days before testing, and after major
maintenance.Sec. 1066.250: Base inertia Upon initial installation and after major
verification. maintenance.Sec. 1066.255: Parasitic Upon initial installation, after major
loss verification. maintenance, and upon failure of a
verification in Sec. 1066.270 or Sec.
1066.275.Sec. 1066.260: Parasitic Upon initial installation, after major
friction compensation maintenance, and upon failure of a
verification. verification in Sec. 1066.270 or Sec.
1066.275.Sec. 1066.265: Acceleration Upon initial installation and after major
and deceleration maintenance.
verification.Sec. 1066.270: Unloaded Upon initial installation, within 7 days
coastdown verification. of testing, and after major maintenance.Sec. 1066.275 Dynamometer Upon initial installation, within 1 day
readiness verification. before testing, and after major
maintenance.------------------------------------------------------------------------\a\ Perform calibrations and verifications more frequently, according to
measurement system manufacturer instructions and good engineering
judgment.
(c) Automated dynamometer verifications and calibrations. In some cases, dynamometers are designed with internal diagnostic and control features to accomplish the verifications and calibrations specified in this subpart. You may use these automated functions instead of following the procedures we specify in this subpart to demonstrate compliance with applicable requirements, consistent with good engineering judgment.
(d) Sequence of verifications and calibrations. Upon initial installation and after major maintenance, perform the verifications and calibrations in the same sequence as noted in Table 1 of this section, except that you may perform speed linearity verification after the verifications in Sec. Sec. 1066.225 and 1066.230. At other times, you may need to perform specific verifications or calibrations in a certain sequence, as noted in this subpart. If you perform major maintenance on a specific component, you are required to perform verifications and calibrations only on components or parameters that are affected by the maintenance.
(e) Corrections. Unless the regulation directs otherwise, if the dynamometer fails to meet any specified calibration or verification, make any necessary adjustments or repairs such that the dynamometer meets the specification before running a test. Repairs required to meet specifications are generally considered major maintenance under this part.