Systems, apparatuses, and methods for providing negative pressure with instillation fluids to a tissue site are disclosed. Some embodiments are illustrative of an apparatus or system for delivering negative-pressure and/or therapeutic solution of fluids to a tissue site, which can be used in conjunction with sensing properties of fluids extracted from a tissue site and/or instilled at a tissue site. For example, a system may comprise a tissue interface adapted to be coupled to a source of instillation fluid and a dressing interface having a therapy cavity that includes a pH sensor, a humidity sensor, a temperature sensor, and a pressure sensor embodied on a single pad within the dressing interface to provide data indicative of acidity, humidity, temperature and pressure at the tissue site. Such apparatus may further comprise algorithms for processing such data for detecting leakage and blockage conditions as well as providing information relating to the progression of healing of wounds at the tissue site. An illustrative method may comprise disposing the tissue interface at the tissue site and the therapeutic cavity in fluid communication with the tissue interface. The method may further comprise instilling fluid to the therapy cavity and then sensing the pressure, humidity, temperature, and the pH of the fluids adjacent the tissue interface. The method may further comprise determining various flow characteristics of the system by using a processing element electrically coupled to the sensors for transmitting property signals from the sensors to a controller configured to assess the property signals in order to identify the flow characteristics.