Pneumatics; Electronics; Figure 1-3. Model 82I Probe Controller Flow Diagram - Thermo Scientific Mercury Freedom 80i Manual

Introduction
Model 82i
Clean, dry, pressurized (~85 psig) air feeds two electo/pneumatic pressure

Pneumatics

transducers which adjust and maintain output pressure to the Model 83i
probe eductor and blowback pneumatics (Figure 1–3).
Pressurized (~85 psig) Hg-free zero air or nitrogen feeds a third
electo/pneumatic pressure transducer which adjusts and maintains dilution
gas pressure to the Model 83i probe dilution module.
Three electronic pressure transducers (Figure 1–3) associated with the
individual regulators are also contained within the Model 82i, as well as an
electronic vacuum transducer monitoring the dilution module vacuum in
the Model 83i.
Figure 1–3. Model 82i Probe Controller Flow Diagram

Electronics

The Model 82i communicates with the Model 80i via a RS-485 link. The
Model 80i acts as the master component in the Mercury Freedom ™
System with both the Models 81i and 82i slaved to the analyzer. All
commands are initiated by the Model 80i. The Model 82i receives
commands and sends information to the analyzer.
The Model 82i also receives two 4-20 mA signals from the probe critical
orifice pressure transducer and the fast loop venturi pressure transducer.
Thermo Fisher Scientific Mercury System Manual 1-5