SOLSTAT EPM-910 Bench/Portable Digital pH/mV Meter

EPM-910 ... Bench/Portable Digital pH Meter
SOLSTAT's bench/portable pH Meter solution
Packaged in an attractive instrumentation case, this unit was designed as a single-purpose (pH) meter.  It was portable, battery operated
(alternatively powered by a wall-wart DC supply), and offered full pH functionality (with Automatic Temperature Compensation).