At Chem-Dry of Tampa FL we use several indicators to find hidden urine spots in carpet. Once urine is deposited in the carpet it can disappear into the backing leaving no visual cues on the carpet fibers itself. That means the carpet can look perfectly fine but urine is lurking in the backing and the pad underneath. You might not notice the urine deposits until they have built up and start to smell like ammonia.
So how do you find urine deposits that leave no trace on the surface? At Chem-Dry of Tampa FL we use 3 different indicators to find urine deposits. The first one is simple, the smell. You can get on your hands and knees and sniff the carpet until you find the offending odor and target to spot for cleaning.
The second indicator of urine is little more scientific. By using a UV light and glasses that filter out the color purple you can see urine fluorescing in the carpet, see the picture above. Broken down blood proteins and a bit of phosphorus in the urine allows it glow under a black light. IF it glows with a slightly green hue, then it's most likely urine.
The third indicator of urine involves using a moisture detector to find hidden urine spots. Urine salts absorb and holds moisture that can easily be detected with a tool that is used to located hidden moisture.
Combining all three of these methods makes finding urine in carpet easy.