Pack Nitriding

A method of surface hardening of steel in which parts are packed in a steel box with the nitriding compound and heated to elevated temperatures.

Partial Annealing

An imprecise term used to denote a treatment given cold-worked material to reduce the strength to a controlled level or to effect stress relief. To be meaningful, the type of material, the degree of cold work, and the time-temperature schedule must be stated.

Patenting

drawing of wire or between drafts. This process consists of heating to a temperature above the transformation range and then cooling to a temperature below Ae1 in air or in a bath of molten lead or salt.

Pirani Gage

An instrument used to measure the pressure inside a vacuum chamber. The gage measures electrical resistance in a wire filament which will change in temperature depending on atmospheric pressure.

Packet

1. A unit of digital information in PACKET COMMUNICATIONS. It consists of a header followed by a certain number of data bits or bytes. 2. See WAVE PACKET. 3. See PACKET COMMUNICATIONS. 4. See PACKET RADIO.

Packet Communications

A method via which data is exchanged through a network between or among people or computers. Information is sent and received in blocks of information called packets. Each packet is routed individually through the network according to the most efficient possible path at the time of its transit. At the destination, the packets are reassembled into the original signal. This scheme makes more efficient use of network resources than continuousconnection or single-path methods. However, when network usage is heavy, there can be a delay in the arrival of a sufficient number of packets to produce an intelligible received signal.