Profile: Doble PowerTest Ltd. is a supplier of diagnostic test instruments and knowledge services to the electric power industry. Our products include circuit breaker diagnostics, insulation analysis equipment, protection, and transformer diagnostics. Our circuit breaker diagnostic products allow to test simple and complex circuit breakers using a single field portable instrument & windows based software. The circuit breaker test system is a precision instrument for testing all types of circuit breakers. It performs timing functions for up to four breaks per phase with motion measurements. Our insulation analyzer evaluates the integrity of high voltage sub-station apparatus by measuring the power factor or tangent delta, along with a number of other essential values. It also measures the capacitance, to evaluate physical changes to the apparatus.