Heat Sensors

Chip: MCP9801

Pricing information*

Part Number	Leads	Package Type	Temp Range	1-25	26-99	100+	1000-4999	5000+
MCP9801-M/MS	8	MSOP	-55C to +125C	1.12	0.93	0.85	0.82	0.81

*from http://www.microchip.com/wwwproducts/Devices.aspx?dDocName=en020950, prices are in USD ($)

±1°C Accuracy from -10°C to +85°C

±2°C Accuracy from +85°C to +125°C

Key:

MSOP: Mini Small-Outline Package - a method of packing the sensors to save board space

Alternate Options

Near-IR radiation: http://fire.nist.gov/bfrlpubs/fire96/PDF/f96140.pdf
By measuring the radiation emmisions it is possible to detect a fire. This method could significantly lower false detection rates, but not yet approved standard.

Proposed system

Multiple temperature sensors in each room of the buliding would send a current temperature reading back to the control system. Any consistent, significant, sudden raise of temperature would trigger the system's fire alarm. By comparing the output of multiple sensors in one room, the system could detect malfunction in any one sensor to both simultaneously increase real detection rates and decrease false detection.