SIEMENS HFP-11 FIRE ALARM SMOKE HEAT DETECTOR HFP11,HFP-BRAND NEW-SHIPS N 24 HRS Condition is Brand New. Brand: SIEMENS Model: HFP-11 FIRE ALARM SMOKE HEAT DETECTOR HFP11,HFP. Shipped with USPS First Class Mail . You Will Receive 1 ea SIEMENS HFP-11 FIRE ALARM SMOKE HEAT DETECTOR HFP11,HFP-BRAND NEW-SHIPS N 24 HRS. RARE VINTAGE COLLECTIBLE SHIPS N 24 HOURS Packed By Our Award Winning Packaging And Shipping Department Long Time E-commerce Seller For Over 20 Years LIMITED AVAILABILITY Follow Our Store For Rare Products Posted Daily and Specials Please click https://www.ebay.com/usr/boughtnowcommerce Inventory Box Number: 407 Description: The HFP-11 is a plug-in, two-wire, multi-sensor detectorwith both photoelectric and thermal inputs and is compat-ible with Fire Finder XLS and FS-250 series of controlpanel systems. Each detector consists of a dust resis-tant, field-cleanable photoelectric chamber, a solid statenon-mechanical thermal sensor, and microprocessorbased electronics with a low-profile plastic housing. TheHFP-11 utilizes state-of-the-art ASIC circuitry and surfacemount technology for maximum reliability. Every HFP-11fire detector is shipped with a protective dust cover. TheHFP-11 fire detector utilizes an infrared light emittingdiode (IRLED), and light sensing photodiode. Undernormal conditions, light transmitted by the LED isdirected away from the photodiode and scattered throughthe smoke chamber in a controlled pattern. The smokechamber is designed to manage light dissipation andextraneous reflections from dust particles or other non-smoke airborne contaminants in such a way as to main-tain stable, consistent detector operation. When smokeenters the detector chamber, light emitted from theIRLED is scattered by the smoke particles and is receivedby the photodiode.