When conducting fieldwork on tone languages, the linguist choosing to use the IPA to make phonetic transcriptions of tone is presented with a challenge: Current methods of tone transcription in the IPA require a degree of phonological analysis before they can be applied and when applied they do not adequately display pitch distinctions relative to other pitches. I describe this challenge and the bar method as a proposed solution. The bar method visually presents F0 distinctions relative to other F0 expressions without ties to segments. I hope this solution facilitates the discussion of phonetic tone transcription without regard to phonological assumptions, linguistic tradition, or geographical area of research.
This was a poster presentation of the full published paper mentioned here.
You should probably just cite the paper which is referenceable as:
Hugh J. Paterson III (2015) Phonetic transcription of tone in the IPA. In The Scottish Consortium for ICPhS 2015 (Ed.). Proceedings of the 18th International Conference of Phonetic Sciences Paper number 507.1-5. University of Glasgow: Glasgow, UK.