Table 3
Gel strength codes and the corresponding gel descriptions, reproduced from Sydansk and Argabright (1987).
| Gel strength code | Gel description |
|---|---|
| A | No detectable gel formed: The gel appears to have the same viscosity as the original polymer solution. |
| B | Highly flowing gel: The gel appears to be only slightly more viscous than the initial polymer solution. |
| C | Flowing gel: Most of the gel flows to the bottle cap by gravity upon inversion. |
| D | Moderately flowing gel: Only a small portion (5–10%) of the gel does not flow to the bottle by gravity upon inversion (usually characterized as a tonguing gel). |
| E | Barely flowing gel: The gel can barely flow to the bottle cap and/or a significant portion (>15%) of the gel does not flow by gravity upon inversion. |
| F | Highly deformable nonflowing gel: The gel does not flow to the bottle cap by gravity upon inversion. |
| G | Moderately deformable nonflowing gel: The gel deforms about half way down the bottle by gravity upon inversion. |
| H | Slightly deformable nonflowing gel: Only the gel surface slightly deforms by gravity upon inversion. |
| I | Rigid gel: There is no gel surface deformation by gravity upon inversion. |
| J | Ringing rigid gel: A tuning fork-like mechanical vibration can be felt upon tapping the bottle. |