SAMPLES AND EVALUATION

A1.1 Evaluation principles (1) Telecom has an obligation to protect all its customers against avoidable malfunctions by ensuring that the whole system meets recognised standards. Any malfunctions can lead the customer to suspect the integrity of the Telecom network. Telecom therefore has to be assured that all equipment connected to its network is likely to meet the minimum standards set by this Specification.

(2) Absolute confidence in the equipment connected would require that every item be thoroughly tested, but this is clearly impractical. For most types of equipment, a test of one unit is accepted as a reasonable means of assessment. However, for telephony devices, the electro-acoustic facilities require a more stringent approach and a minimum sample of three units are required to be tested.

* Previously, Specification PTC 202 called for 20 samples of telephones to be tested.

(3) Limits in this Specification make full allowance for production tolerances.

* Telecom accepts that any production process needs to have some allowance for process and component variability and the various limits have been set as a compromise between network ideals and typical production capability.

A1.2 Number of samples

A1.2.1 Simple telephony devices (1) For all simple telephony devices, a sample of three units shall be submitted to a recognised Testing Authority for each electrical/acoustic design for testing against this Specification. All three units should meet requirements before a Telepermit can be granted.

(2) Telecom, however, reserves the right to call for larger samples to be tested if the test results and/or other information supplied indicate doubtful compliance. If considered necessary, Telecom will call for a sample of 20 units to be tested against selected clauses of Section 4, and an acceptable quality level (AQL) of 10 % defective (ref. British Standard BS 6002) will be used to determine acceptability.

(3) Should test results indicate that a sample made up of two or more types of telephone claimed to be "electro-acoustically identical" actually consists of differently performing designs, the Testing Authority shall arrange for additional units to be provided by the Applicant to make up the full sample of each type.

A1.2.2 Other devices (1) A sample of one unit of non-telephony devices shall be submitted to a recognised Testing Authority for testing against this Specification.

(2) Also, at the discretion of Access Standards, for more complex or specialised telephony devices, testing of only one unit may be accepted.