There are a number of sensors for monitoring room temperature and humidity. Most of them are integrated into the network as independent network devices, and are normally addressed via SNMP.
But you have to spend at least three hundred dollars on your first sensor. Searching for a cheaper and modular system, the author finally came across http://www.pcmeasure.com/; it has met all his requirements until now.
The fact that this chapter is restricted to this sensor is not meant to detract from other systems, but is down to the fact that this topic alone would be enough for a separate book.
A complete monitoring system for physical data normally consists of three components: ...