How to Measure
Water must be applied to
the affected area and to non-affected spot. The non-affected spots can be very
close in proximity to the affected spot. The best applicator is trigger sprayer
applying a mist. The more water that is added, the more the pH will shift
towards ‘7’. The flat surface probes have an advantage here on requiring the
least amount of water. Next, agitate the areas for testing with a clean bone
scraper. Agitating with a towel or a hand can help corrupt the readings by
introducing other substances to the spots. If the probe has been sitting in
another solution such as a soaker bottle for the flat surface probe, then rinse
it off with tap water. Apply the probe to the area to be tested and ignore the
first two or three readings. Agitating the faceyarn with the probe will give
better results and dragging it from the problem area to an adjacent area can
reveal a wealth of information. However, using the probe in this manner will
shorten its life, especially on the flat surface probe.
|
AREA |
pH |
Source |
Additional Action |
|
Spot |
Less than 3 with color loss |
Strong Acid: toilet bowl cleaner, tile cleaner are
likely, HCl or car battery acid, H2SO4 or a rust stain
spotter residue. |
Neutralize with strong alkaline detergent to a pH of 6
to 8. On nylon, spot dyeing may be difficult if not impossible due to fiber
degradation. |
|
Overall |
3 to 6 |
On new nylon & wool carpets, Acid dye lock |
Check Colorfastness at higher pH by soaking yarns in
solutions |
|
Spot |
From 3 to 6.0 and sticky |
Food Related |
Try spotting with tannin spotter or enzymes. See the
carpet cleaner’s HANDBOOK by the Academy of Textiles and Flooring for
specific pHs of specific foods. |
|
Overall |
4.0 to 5.5 & clean |
Acid Rinse |
None |
|
Overall |
6.0 to 6.7 & soiled |
Typical pH for Soil |
Typical pH for Soil indicating no recent cleaning. |
|
Spot |
0.3 to 1.0 less than surrounding carpet and smells like
urine |
Urine |
Run other tests to confirm urine i.e. black light &
moisture. Neutralize to a pH of 6 to 8. If there is color loss on nylon,
spot dyeing may be difficult if not impossible. |
|
Spots |
Between 2 to 4 points lower than surrounding carpet
with color loss |
Metal cleaners that contain reducing agents. |
Neutralize with alkaline oxygen bleach to a pH of 7 to
8, and then repair the color. |
|
Overall |
7.0 & clean |
Neutral Rinse, some low moisture methods are buffered
at pH 7.0 |
None |
|
Overall |
7.3 to 8.0 |
The carpet has been cleaned, likely with HWE with Stain
Resist Detergent |
Check the fluorochemical protection by gently placing
baby oil on the yarns to see if they bead and the stain resistant by soaking
the yarns in dye for three minutes and rinsing with tap water. |
|
Overall |
8.1 to 8.7 |
HWE with pH 10.0 Detergent |
Recommend acid rinse in cleaning and checking the
protectants. |
|
Overall |
8.8 to 9.2 |
HWE with High pH Detergent |
Recommend acid rinse in cleaning. Look for bleeding.
|
|
Spot |
9.5 & higher with possible color loss |
Oven Cleaner or bleach. If there is a color loss on
nylon or missing yarn on wool, the household bleach is the problem |
Neutralize household bleach with a strong acid and/or
sodium bisulfite to a pH between 6 & 7. For nylon, consider spot dying. |