Model 82I; Figure 1-2. Model 81I Flow Diagram - Thermo Scientific Mercury Freedom 80i Manual

Introduction

Model 82i

Model 82i
1-4 Mercury System Manual
Figure 1–2. Model 81i Flow Diagram
The output of the low flow MFC is passed through a coiled, Teflon
encapsulated Hg source, which is maintained at a precisely known
temperature and pressure. The Hg saturated flow is directed by Valve V2
(NC) to combine with dilution flow from Valve V3 (NC) providing
calibration gas to either:
A Hg analyzer via Valve V5 (NC)
●
Or the Hg probe via Valve V5 (NO)
●
Calibration gas to the probe is sent directly to the critical orifice or to the
spike port (for filter flooding) by switching the appropriate probe valve
(orifice or spike).
The check valve is used to keep the orifice (located in the probe) from
being over pressurized during an orifice zero or calibration.
Excess flow (atmospheric dump) during a probe calibration is routed
through an internal Hg scrubber prior to being sent to exhaust. Also during
any zero air mode (instrument, orifice, or system), the Hg saturated flow is
directed via V2 (NO) through a Hg scrubber prior to being sent to exhaust.
The Model 82i Mercury (Hg) Probe Controller is configured as one
component of the Thermo Scientific integrated Hg Continuous Emission
Monitoring System (CEMS). The Model 82i is not available as a stand-
alone instrument.
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