A useful tool in rug washing is a Hydrosensor. Most people call it a moisture probe or moisture detector. After the squeegee, it’s probably the tool we use most often throughout the day. It’s mostly used to see if a rug is dry or not, but it can also be used to detect urine in a rug.

This Karastan came to us wrapped in plastic. The owner had a carpet cleaner steam clean it, afterwards they wrapped it in plastic. It was heavily contaminated with urine, so much that even just slightly touching the rug with our Hydrosensor prongs made the sensors go off like an alarm.

When urine dries, it turns into a salt. Those urine salts attract moisture. So despite the rug being dry, it’s going to always contain a small amount of moisture.

We like to keep our Hydrosensor tools handy, so we used 2″ PVC pipe and attached them to our rug drying wrack with zip ties. This keeps them close and safe.


A moisture meter can also be used to detect moisture in rugs. This tool is mostly used to detect moisture in drywall, but we can use it for pet urine. It’s not technically detecting pet urine, it’s just detecting the moisture in the rug that are a result of pet urine salts.

You can see the meter detecting more moisture as it gets closer to the areas with pet urine contamination.