Instrumentation and controls for operation of no. 2 soaking pits at fairless works

This paper describes the instrumentation and controls for operation of soaking pits. All components of the system are plug-in units of the solid-state type, except for input switching, which are mercury-wetted relays. The input signals to the logger emanate from sixty-four chromel-alumel thermocouples with a range of 0–2500°F. The points are periodically logged on thirty-minute intervals as well as on demand. Continuous scanning takes place at the rate of one point per second between the periodic logs. Upon detection of an off-normal signal, one that has exceeded the set point, all points will be logged with the off-normal being printed in red. When the process returns to normal, all points are logged again even between periodic logging time. With the detection of each off-normal, the alarm will sound and continue to sound until acknowledged by the operator.