(a) Portable air compressor or compressor means any wheel, skid, truck, or railroad car mounted, but not self-propelled, equipment designed to activate pneumatic tools. This consists of an air compressor (air end), and a reciprocating rotary or turbine engine rigidly connected in permanent alignment and mounted on a common frame. Also included are all cooling, lubricating, regulating, starting, and fuel systems, and all equipment necessary to constitute a complete, self-contained unit with a rated capacity of 75 cfm or greater which delivers air at pressures greater than 50 psig, but does not include any pneumatic tools themselves.

(b) Maximum Rated Capacity means that the portable air compressor, operating at the design full speed with the compressor on load, delivers its rated cfm output and pressure, as defined by the manufacturer.

(c) Model year means the manufacturer's annual production period which includes January 1 of such calendar year; Provided, that if the manufacturer has no annual production period, the term “model year” shall mean the calendar year.

(d) Compressor configuration means the basic classification unit of a manufacturer's product line and is comprised of compressor lines, models or series which are identical in all material respects with regard to the parameters listed in § 204.55-3.

(e) Category means a group of compressor configurations which are identical in all aspects with respect to the parameters listed in paragraph (c)(1)(i) of § 204.55-2.

(f) [Reserved]

(g) Noise emission test means a test conducted pursuant to the measurement methodology specified in § 204.54.

(h) Inspection Criteria means the rejection and acceptance numbers associated with a particular sampling plan.

(i) Acceptable Quality Level (AQL) means the maximum percentage of failing compressors that, for purposes of sampling inspection can be considered satisfactory as a process average.

(j) Batch means the collection of compressors of the same category or configuration, as designated by the Administrator in a test request, from which a batch sample is to be randomly drawn and inspected to determine conformance with the acceptability criteria.

(k) Batch sample means the collection of compressors that are drawn from a batch.

(l) Batch sample size means the number of compressors of the same category or configuration which is randomly drawn from the batch sample and which will receive emissions tests.

(m) Test sample means the collection of compressors from the same category or configuration which is randomly drawn from the batch sample and which will receive emissions tests.

(n) Batch size means the number, as designated by the Administrator in the test request, of compressors of the same category or configuration in a batch.

(o) Test sample size means the number of compressors of the same configuration in a test sample.

(p) Acceptable of a batch means that the number of non-complying compressors in the batch sample is less than or equal to the acceptance number as determined by the appropriate sampling plan.

(q) Rejection of a batch means that the number of non-complying compressors in the batch sample is greater than or equal to the rejection number as determined by the appropriate sampling plan.

(r) Acceptance of a batch sequence means that the number of rejected batches in the sequence is less than or equal to the sequence acceptable number as determined by the appropriate sampling plan.

(s) Rejection of a batch sequence means that the number of rejected batches in a sequence is greater than or equal to the sequence rejection number as determined by the appropriate sampling plan.

(t) Shift means the regular production work period for one group of workers.

(u) Failing compressor means that the measured noise emissions of the compressor, when measured in accordance with the applicable procedure, exceeds the applicable standard.

(v) Acceptance of a compressor means that the measured noise emissions of the compressor, when measured in accordance with the applicable procedure, conforms to the applicable standard.

(w) Test Compressor means a compressor used to demonstrate compliance with the applicable noise emissions standard.

(x) Tampering means those acts prohibited by section 10(a)(2) of the Act.