A low weight encoding circuit of a power delivery system for encoding data sent out on an IO bus with minimal current drawn so as to minimize signal and timing distortions. The counting information collection unit collects counting information including detection time of a gamma ray from a counting result output by a detector for counting light derived from a gamma ray, and stores the counting information in a buffer. The structure has a rated K-factor defining an expected flow of fluid in gallons per minute from the outlet divided by the square root of the pressure of the flow of fluid fed into the inlet of the passageway in pounds per square inch gauge.