The Megger 249000 series calibration shunt calibrates a Megger 247000 series or DLRO10 series digital low resistance microhmmeter (sold separately). The shunt verifies the accuracy of the microhmmeter because the resistance of the shunt at a given current is known. The 249000 series is used to conduct more accurate resistance tests with a DLRO10 series microhmmeter.

Megger manufactures equipment for cable fault locating, protective relay testing, telecommunications and data integrity, and power quality testing under multiple brand names, among them Megger, Biddle, States, and AVO. The company, founded in 1889, is headquartered in Dover, England, and meets International Organization for Standardization (ISO) 9001:2008 standards.