Transmitance or Transmittance: How To spell?
The word Transmitance is misspelled against Transmittance, a noun meaning "Transmission."
Transmittance has double "tt" is mispronounced as "t"Remember double 'TT' in between the strings transmi & ance which should not be misspelled with single 'T'
Wrong Spelling:  transmi-t-ance  Correct Spelling:  transmi-tt-ance 
Find more wrongly spelled words of Transmittance to spell it well.