, Billerica, MA, offers the HygroTrac wireless system for monitoring environmental conditions remotely in buildings, to check for moisture-related problems. Small HygroTrac wireless sensors are installed throughout a building to monitor RH, temperature, and moisture content. Readings are transmitted to the DA gateway that is connected to a dedicated secure Web server via Ethernet or phone line. A single gateway can receive data from up to 600 sensors that can be installed in a 150–250 ft. area. You can view data live on the Web site as well as send email warnings to a PC or mobile phone.