Instrument Transformer Meter Multiplier Calculator
Combine CT and PT ratios and scale a register or pulse reading while accounting for an existing meter multiplier.
Enter instrument values
Use 1 when the input reading has not already been multiplied.
Meter scaling
About this calculator
Combine CT and PT ratios and scale a register or pulse reading while accounting for an existing meter multiplier.
Verify meter programming, pulse constants, units, and any billing multiplier before applying the result. This calculator cannot determine whether the entered meter configuration is correct.
Method and assumptions
CT ratio = CT primary ÷ CT secondary. PT ratio = PT primary ÷ PT secondary. Adjusted value = entered register value × CT ratio × PT ratio ÷ multiplier already applied to that reading.
Calculated results reflect only the ratios, spans, burdens, and readings entered. Verify instruments, wiring, polarity, configuration, and manufacturer limits independently.
FAQs
Can I open or disconnect a current transformer secondary while energized?
No. Never open an energized CT secondary. Follow approved electrical safety procedures and manufacturer instructions.
Does a calculated value verify billing or instrument configuration?
No. Confirm whether the meter or register already applies CT/PT scaling and verify the configured ratios with the metering documentation.
Sources
Use instrument nameplates, meter configuration records, transmitter setup data, and manufacturer compliance-voltage specifications for the installed equipment.