The Siemens DI-B3 is a legacy ionization smoke detector head. Specifically, the product’s short description identifies it as a duct-use-only application. The Siemens part number is 500-085081.
First, the DI-B3 senses combustion particles using an ionization chamber. Then the detector signals alarm to the panel through its companion B-series base. As a result, the panel reports the alarm and triggers system response.
In addition, ionization detectors respond quickly to fast-flaming fires. Therefore, the DI-B3 was widely specified for combustion-particle-heavy fire scenarios in legacy Siemens installations.
About the Siemens DI-B3 Legacy Detector
The DI-B3 is part of the Siemens DI-series detector family. Specifically, the “B” designation indicates the B-series base interface. As a result, the DI-B3 plugs into a different base than the standard DI-3 head. Furthermore, this product line is no longer in current production — Siemens has phased out ionization in favor of photoelectric and intelligent detectors.
Important Notes Before Ordering
- Confirm your base matches the B-series interface before ordering
- The short description lists this part for duct-use-only application — verify with your system designer
- Reconditioned or new-old-stock units may be the only available source
- Many jurisdictions restrict ionization detector replacements; confirm local code compliance
Replacement Sourcing
The DI-B3 is increasingly difficult to source as a new OEM part. Therefore, facilities maintaining legacy Siemens fire alarm infrastructure should plan ahead. Specifically, holding a small spare-parts inventory is the typical approach.
Order or Get Application Help
Life Safety Consultants specializes in legacy Siemens fire alarm components. For questions about the DI-B3, base compatibility, or your specific panel, call 1-888-557-0558. Alternatively, email sales@lifesafetycom.com.
For more information, contact the Life Safety Consultants team at (888) 557-0558, or email us at: sales@lifesafetycom.com
Additional information
| Weight | .5 lbs |
|---|---|
| Dimensions | 6.5 × 6.5 × 2.5 in |
| Part Type | Duct Detector / Housing, Smoke Detector |
| Manufacturers | Siemens |
| Compatible Panels | Siemens legacy conventional fire alarm panels, Siemens DI-series compatible panels |
| Compatible Bases | B-series Siemens detector base (verify specific base part number) |
| Cross Reference | DI-B3, DIB3 |
| Specification | Ionization detection technology, B-series base configuration, legacy Siemens DI-series product family, for use with compatible Siemens fire alarm control panels |







