P19.7
Streak-Free Performance — Standardized Soiled Panel Test
Procedure 28 of 40 · Chapter 19 · §19.3.2
2 tables 0 notes
Table 1
| Score | Description | Criteria |
|---|---|---|
| 5 | Perfect | No visible streaks, droplets, haze, or film; optically clear |
| 4 | Excellent | Faint streaks visible only under close inspection ( cm) at oblique angle |
| 3 | Good | Visible but minor streaks at 30 cm; haze present but view not obstructed |
| 2 | Poor | Clearly visible streaks or film at 30 cm; cloudy or greasy appearance |
| 1 | Unacceptable | Heavy opaque film; view significantly distorted; requires re-cleaning |
Table 2
| Parameter | Test method | Acceptable range | Notes |
|---|---|---|---|
| Clarity | Visual, black background | Clear, no suspended matter | Settle 8 h minimum after manufacture |
| pH | Glass electrode, 25 °C | 7.0 – 10.5 | pH > 10.5 risks skin irritation and ammonia odor |
| Evaporation time | P19.6 (25 °C, 50 % RH) | 15 – 30 s | < 15 s may dry too fast; > 30 s risks residue |
| Streak score | P19.7 (1–5 scale) | (mean of 3 assessors) | < 3.0 indicates unacceptable residue |
| Non-volatile residue | Gravimetric (P19.6) | μg/cm² | Higher NVR correlates with streaking |