Abstract: A method for maintaining the optimal argon injection flow rate which will result in production of steel slab of a chosen alloy having optimal cleanliness. The steel is cast using an argon injected slide gate. The selected steel has a known optimal argon injection flow rate Qb* for casting steel of optimal cleanliness. The method involves calculating the present steel pressure and determining the present injection flow rate conductance Gb? of the argon injected slide gate during either of 1) a steel pressure change event; or 2) an argon flow change event. The measurements are used to calculate present argon pressure required to insure the required injection flow rate of argon into the steel for optimal cleanliness of the cast steel.

Abstract: Testing methods and apparatus for testing the health of steel tubes used in reformers and other tubes and pipes used in other high temperature applications are provided. The method includes the steps of transmitting two sinusoidal electromagnetic signals, each having a different frequency F1 and F2, into the reformer tube, receiving a response signal, and analyzing the received response signal's intermodulation frequencies to determine the state of the steel reformer tube.

Abstract: Testing methods and apparatus for testing the health of steel tubes used in reformers and other tubes and pipes used in other high temperature applications. The method includes the steps of transmitting two sinusoidal electromagnetic signals, each having a different frequency F1 and F2, into the reformer tube, receiving a response signal, and analyzing the received response signal's intermodulation frequencies to determine the state of the steel reformer tube.

Abstract: Testing methods and apparatus for testing the health of steel tubes used in reformers and other tubes and pipes used in other high temperature applications are provided. The method includes the steps of transmitting two sinusoidal electromagnetic signals, each having a different frequency F1 and F2, into the reformer tube, receiving a response signal, and analyzing the received response signal's intermodulation frequencies to determine the state of the steel reformer tube.

Abstract: Testing methods and apparatus for testing the health of steel tubes used in reformers and other tubes and pipes used in other high temperature applications. The method includes the steps of transmitting two sinusoidal electromagnetic signals, each having a different frequency F1 and F2, into the reformer tube, receiving a response signal, and analyzing the received response signal's intermodulation frequencies to determine the state of the steel reformer tube.

Abstract: A wireless local area network (10) includes a plurality of stations (12) adapted to transmit and receive message packets via a distribution system (30). In a time division multiplexing embodiment the network (10) operates using successive timing frames (FR1, FR2, etc.) each consisting of three timing intervals (T1, T2, T3). During the first timing interval (T1) the distribution system (30) normally transmits synchronizing packets (HBT), to which a station (12) desiring to transmit responds by transmitting an information packet during the next second timing interval (T2). During the subsequent first timing interval (T1), the distribution system (30) retransmits the received information packet.

Abstract: Testing methods and apparatus for testing the health of steel tubes used in reformers and other tubes and pipes used in other high temperature applications. The method includes the steps of transmitting two sinusoidal electromagnetic signals, each having a different frequency F1 and F2, into the reformer tube, receiving a response signal, and analyzing the received response signal's intermodulation frequencies to determine the state of the steel reformer tube.