The Temperature Sentinel is an industrial grade, Ethernet data acquisition product for monitoring temperature within the range of -67°F to +257°F (-55°C to +125°C) and is equipped with one SPDT electro-mechanical relay and the ability to communicate with up to four digital temperature sensors and one optically isolated status/digital input. It can be controlled and/or monitored over any IP network including private networks, IP-based industrial control networks, and the Internet. Users can operate the product using a web browser or web-enabled mobile device, while email notification may be configured to alert up to four recipients when alarms are detected. The user may also enable a sound effect to play when an alarm is generated. Logging of configured data acquisition conditions and site ID may be emailed from once an hour to once a day. The electro-mechanical relay can be controlled through the web server interface as well as be setup to respond to alarm conditions based on the temperature sensors and/or input condition. The Temperature Sentinel is very easy to set up using a web browser. It has a simple Monitor/Control Page, which displays the temperature readings of the four digital temperature sensors that are connected to the unit, as well as the current state of the SPDT relay and optically isolated status/digital input.