World-wide oil industry demands resulted in a stand-alone, battery powered, digital/analog display, intrinsically safe pressure sensing and display system which has made obsolete all previous instrumentation. Houston Digital Instruments manufactures a line of battery operated stroke counters and choke position indicators. Other non-drilling applications include ballast control monitoring stations and riser tension applications. HDI has also developed pit volume totalizer systems and BOP test systems, which are based on the same technology.\r\n\r\nHDI has anticipated the need for new and innovative designs and has recently developed a microprocessor base that is being used in the expansion of its instrument line to include: SPM and RPM meters, Tong Torque, Rotary Torque, Crane Scale Systems, Bulk Weight Systems, Complete Drilling Consoles and Drilling Weight Indicator Systems.\r\n\r\nThis group has a combined experience of more than forty years of direct customer contact, both in the field on drilling rigs, and in the design and manufacture of solutions to instrumentation and drilling process monitoring problems.