73478089
Apr 30, 1984
Jul 2, 1985
A MECHANICAL INSTRUMENT FOR RECORDING DATA CONCERNING WELL DRILLING OPERATIONS, SUCH AS DRILLING TIME IN MINUTES PER FOOT, ROUND TRIP TIME FOR CHANGING BITS AND ADDING JOINTS, SHUT-DOWN TIME AND THE LIKE; PRESSURE GAUGES, PRESSURE TRANSMITTERS, LEVEL TRANSMITTERS, INSTRUMENTATION CONSOLES AND FLOW TRANSMITTERS, ALL FOR USE IN THE WELL DRILLING INDUSTRY
Electrical and Scientific Apparatus