DRJAYNE , I believe the conversion you are referring to is a different scale that can be used to measure PPM (parts per million). Some meter have more than one measuring function, EC and TDS are the most common.
using 1 gallon of RO water I added 5ML/CC of GHGrow which gave me 750ppm, and then I added 10ML/CC GHBloom and get a reading of 1290ppm/ 1.90EC. My syringe has a nozzle so my measure of 5/10 is prolly more like 7/12 to be honest. So if you converted ML/CC to TBS./TSP. you'd have your answer based on my meter.
Does that help?
Also, I found this:
Calculated EC/TDS levels:
EC microsiemen:
0-4-8: 946 µS
0-5-10: 1184 µS
0-8-16: 1894 µS
TDS @ 0.5 conversion:
0-4-8 = 473 ppm
0-5-10 = 592 ppm
0-8-16 = 947 ppm
TDS @ 0.7 conversion:
0-4-8 = 663 ppm
0-5-10 = 829 ppm
0-8-16 = 1326 ppm