Environnement AS32M, Technical Manual, Page: 19 / 186

Duplication prohibited
AS32M
Environnement
S.A
DECEMBER 2013
1–11
1.1.2.5 Internal view of AS32M equipped with the permeation bench option
The mechanical and physical parts (see Figure 1–8)
Il includes the following elements:

The filter / solenoid valve assembly (1) and (2),

A thermal-insulated enclosure including the following:

Dryer (4)

Particles filter (5)

Optical cavity (6) and LED

Phototube (7)

The pump (8).
After passing through the sample inlet dust filter (1), the sample to be analyzed is directed towards a
block consisting of two 3-way solenoid valves (2).
These solenoid valves allow selection of the following:

In MEASUREMENT mode, the sample gas to be analyzed.

In ZERO mode, the ambient air filtered through the active charcoal filter (9).

In SPAN mode, a span gas that comes from the optional permeation bench.
The sample to be analyzed is aspirated through a permapure drier in reflux mode (4) and a dust filter
towards the optical cavity (6) closed at both ends by semi-transparent mirrors of high reflectivity. Light
emitted by the LED at 450 nm is detected by the phototube to the other end of the cavity (7).
The temperature of the optical cavity is controlled at 45 ° C by the microprocessor associated with a
PT100 sensor and a heating laminar.
A restrictor located at the optical cavity outlet enables the sample flow rate control and the dryer
operation in reflux mode. It is then exhausted towards outside by a membrane pump (8).
The permeation bench (16) consists of an aluminum chamber inside which is placed the permeation
tube. A bypass with restrictor is added to ensure the permanent ventilation of the permeation tube in
the bench.
The electric and electronic part (see Figure 1–8)
The electrical part consists of universal power supply block (10) delivering a voltage of 24VDC-225W
to generate all the necessary voltages. The analyzer can be connected to an AC supply voltage from
85 to 240VAC 50-60Hz.
The electronics consists of the following:

Pre-amplifier board and heterodyne demodulator (11),

LED driver and counting board (12),

Pressure sensor board (13),

Module board (14),

DNP-Arm7 board (15), which ensures the "dialogue" with the module board and keyboard / display
interface.

RBC board (17) to control the bench heating.

Adaptation board (18) to connect the bench to the Module board.