Chemcassette ® Detection System; Detector Optics; Stain Pattern - Honeywell Vertex M Technical Handbook

Vertex M 24-Point Continuous Monitor
TM
• Top exhaust port
There are 24 inlets, one for each monitored location.
One exhaust port is also located on top of the Vertex
M cabinet.
1.6 Chemcassette
The Chemcassette
contained, microprocessor controlled analyzer that
occupies one slot in a Vertex M. Sample lines and the
vacuum source are connected to the Chemcassette
via a single 10-tube connector.
The system powers up in the same state as when
powered down. Data is stored in the module's memory
until the data acquisition computer retrieves it.
The Vertex M Analyzer modules use the Honeywell
Analytics' Chemcassette
Analyzer modules sample and detect a specific gas
or family of gases.
• Each eight-point Analyzer module:
• Manages Chemcassette
• Provides optical detection of stain
• Directs sample flow through the
Chemcassette
®
• Stores data for retrieval by the data acquisition
computer
Components of the detection system include:
• Chemcassette
®
• Optics and electronics for the detection system
• Chemcassette
®
• Self adjusting proportional valves

1.6.1 Detector Optics

The heart of the Chemcassette
Section 1 - Introduction
Detection System
®
Analyzer module is a self-
®
optical detection system.
®
tape transport
®
detection tape
tape transport mechanism
module is an optical
®
detection system that measures a stain that develops
on the Chemcassette
target gas. Each eight-point Analyzer module has two
detection heads, each with four individual detectors.

1.6.2 Stain Pattern

The following chart shows the stain pattern of sample
detection on the Chemcassette
®
When monitoring a location, the system detects and
measures a specific gas or a family of gases in the
sample. The microprocessor in the analyzer module
interprets the data and responds appropriately.
In the legacy detection system, the sample enters
the inlet and passes through the Chemcassette
tape to the sample outlet. The target gas in the
sample flow reacts with the tape and produces a
stain density proportional to the gas concentration.
An LED in the detector head illuminates the sample
stain and the detector then optically measures the
stain.
1-14
tape in the presence of a
®
tape.
®