| Sensabaugh and Cundiff (1967) | Puff-by-puff measure of whole smoke (vapour and PM) using solvent-coated glass electrode in smoke aerosol | RJ Reynolds Tobacco Company (RJRTC): Sensabaugh technique used internally for “several years” before 1971 |
| | Brown & Williamson Tobacco Company (BWTC): Used experimentally… “Work reported by Honeycutt, Frank, and Johnson showed a range of over one pH unit… for similar cigarettes of the same brand style.” (1984–1989) |
| Backhurst (1966) | Aqueous (cold-trapped) whole smoke measure using pH electrode | BWTC: Experimental use only |
| Artho and Grob (1966) | Measure of smoke pH of PM collected on Cambridge pad and dissolved in water | BWTC: Adopted as standard method, used until 1987, and in altered form through 1997 |
| | Lorillard Tobacco Company (LTC): Used internally by Ihrig, others 1969–1973 |
| Linder and Frank (1984) | Puff-by-puff measure of smoke pH using PM collected on Cambridge pad | BWTC: “this work was reported in a little-known file note” in 1984 |
| “Philip Morris” method (1970) | Whole smoke measure, no puff profile | Philip Morris (PMTC): Standard method, at least as early as 1970 |
| Lakritz (1975) | Measure of both whole smoke and vapour phase using platinum-sliver, silver chloride electrode | LTC: Internal method |
| Harris and Hayes (1977) | Whole smoke measure using pH electrode, modifying Sensabaugh method (with no puff profile) | BWTC: Used experimentally in 1990 |
| ISFET whole smoke method (1997) | Whole smoke measure, modifying Harris-Hayes method with use of solid-state probes (not glass electrode) | BWTC: Adopted in 1997 |