Analog Devices Inc. EVAL-CHAMBER

Overview

EVAL-CHAMBER from Accumold Corporation is a precision-machined optical smoke chamber designed for integration with the ADPD188BI optical sensor IC. It features critical internal dimensions including 11.80±0.05 mm ID, 12.50 mm outer diameter, and 30 mm height, with angular tolerance ±1° and positional alignment controlled to ±0.0002" on critical features. It enables reliable light-scattering detection in residential and commercial smoke alarms.

For engineers reviewing the EVAL-CHAMBER datasheet, EVAL-CHAMBER mechanical drawing, EVAL-CHAMBER mounting interface, or EVAL-CHAMBER compatibility with ADPD188BI, key considerations include internal cavity geometry, optical path alignment, dimensional repeatability across production lots, and thermal stability under UL/EN smoke alarm environmental test profiles.

Technical Context

The EVAL-CHAMBER is a passive optical cavity component that defines the physical sensing volume and light path between the ADPD188BI's integrated LED emitters and photodiode receivers. Its internal surface finish, wall geometry, and inlet/outlet port placement directly influence scattering efficiency and false-alarm immunity.

Manufactured via high-precision micro-molding per Accumold drawing 28800X Rev B, it conforms to third-angle projection standards with critical tolerances held to ±0.0002" (±5 µm) on datum-controlled features. Dimensional compliance ensures repeatable optical coupling and mechanical registration to the ADPD188BI evaluation PCB.

Key Specifications

Availability

EVAL-CHAMBER is available at Aetrix Electronics and suitable for smoke detector development, UL-certified alarm system prototyping, and optical sensing validation requiring stable component supply and traceable mechanical specifications.

Supply support for EVAL-CHAMBER includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Accumold Corporation is a U.S.-based precision micro-molding specialist serving medical, sensing, and optical markets with sub-10 µm tolerance capability and ISO 13485 certification.

The 28800X product line delivers application-specific optical cavities engineered for co-design with Analog Devices' ADPD188BI, targeting low-noise, high-reliability smoke detection systems compliant with UL 217 and EN 14604.

FAQ

What is the primary function of the EVAL-CHAMBER in a smoke detection system?

The EVAL-CHAMBER serves as the calibrated optical sensing chamber that houses the ADPD188BI sensor IC. It defines the precise light-scattering volume where smoke particles interrupt the LED-to-photodiode optical path. Its geometry and surface finish are optimized to maximize signal-to-noise ratio and minimize false alarms. The EVAL-CHAMBER must be used with the ADPD188BI to achieve specified detection sensitivity and response time per UL 217.

Is the EVAL-CHAMBER compatible with sensors other than the ADPD188BI?

No - the EVAL-CHAMBER is mechanically and optically tuned specifically for the ADPD188BI's dual-LED/dual-PD architecture, emitter wavelength (525 nm and 850 nm), and PCB footprint. Its internal dimensions, port locations, and alignment datums do not support interchangeability with other optical sensors. Use of EVAL-CHAMBER with non-ADPD188BI devices is not validated or supported.

Does the EVAL-CHAMBER include mounting hardware or PCB assembly?

No - the EVAL-CHAMBER is a standalone machined plastic component without screws, gaskets, or circuitry. It is intended for manual or automated press-fit installation onto an ADPD188BI-equipped evaluation board (e.g., ADPD188BI-ARDZ). No soldering, adhesives, or fasteners are supplied with the EVAL-CHAMBER unit itself.

What dimensional standard does the EVAL-CHAMBER drawing follow?

The EVAL-CHAMBER drawing follows ANSI Y14.5-2018 geometric dimensioning and tolerancing (GD&T) standards, with third-angle projection and dual-unit annotation (inches/mm). Critical dimensions are annotated with star (*) symbols and controlled to ±0.0002", per Accumold drawing 28800X Rev B dated 9/30/2019. All tolerances are explicitly stated - no defaults apply.

How does the black ABS material contribute to EVAL-CHAMBER performance?

The black ABS material provides >99% diffuse light absorption across 400–1000 nm, eliminating internal reflections that would corrupt the ADPD188BI's scattered-light measurement. Its low outgassing and thermal stability (−10°C to +60°C operating range) prevent contamination of optical surfaces and maintain dimensional integrity during smoke alarm temperature cycling tests required by UL 217.