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JEMStar II CAISO Approved

Monday, April 1, 2019

ROCHESTER, NY, U.S.A. – ISO metering sites in California can now use the AMETEK Power Instruments’ JEMStar II meter, which received the CAISO approval.


The JEMStar II has the highest accuracy in the market at 0.05% of reading for watt hours. The JEMStar II is often used to measure hundreds of thousands of dollars of electricity revenue at utility generation and transmission substations and the industry best 0.05% accuracy will ensure you account for all of it. The JEMStar II has an industry first color graphic display for showing real time power values, meter status, site conditions and more. The meter has 7 communication ports available including dual independent Ethernet ports with security to meet NERC CIP requirements. The JEMStar II has advanced power quality monitoring to provide quick and easy analysis of system anomalies.

“The innovative, straightforward JEMWARE configuration Software makes our meter the easiest one to use” says AMETEK’s Product Manager Steve Bleier. “Most meter technicians can configure our JEMStar II with no assistance required.”  On the industry leading high accuracy for watt hours, “While we guarantee the 0.05% accuracy for 10 years, we were quite impressed with the typical accuracy of 0.02% and this will be a great benefit for our California customers that use this as their cash register”.

AMETEK Power Instruments is a unit of AMETEK, Inc., a leading manufacturer of electronic instruments and electromechanical devices with annualized sales of approximately $4 billion. For more information, contact AMETEK Power Instruments, 255 North Union Street, Rochester New York 14605 Web site:

CONTACT: Steve Bleier (585) 238-4078,