Servomex SERVOTOUGH Oxy, Operator'S Manual

Page: 13 / 145

01910001B_8 © Servomex Group Limited. 2020
1
1.
DESCRIPTION AND DEFINITIONS
1.1
Description
The
analyser is designed to provide stable, accurate and specific gas concentra�on measurements, and
is suitable for use in hazardous areas.
The
analyser uses a paramagne�c transducer to determine the oxygen (O
2
) content of gas samples in
concentra�ons of up to 21% in any background mixture, including con�nuously flammable backgrounds.
The
analyser is simple to operate, with an intui�ve user interface.
Gas
sample measurements are shown on the analyser display, and are also provided as milliamp (mA)
outputs and via Modbus digital communica�on (RS485 and Ethernet). The analyser also provides fault,
concentra�on, maintenance required and service in progress alarms and milliamp (mA) range indica�on
via 30Vdc 1A relay signal outputs.
The
analyser can also be equipped with an op�onal pressure sensor, Flowcube (F3) flow sensor
technology, sample compartment heater and auto valida�on 30Vdc 1A relay signal outputs.
The
analyser requires litle rou�ne maintenance, other than calibra�on (which is essen�al for the
accuracy of sample gas measurements).
1.2
Construction
The
analyser comprises an aluminium enclosure, with Viton® and silicone rubber seals.
Refer to Figure
1. The
analyser has two internal compartments:
1.2.1
Sample/control
com partm ent:
This compartment is accessed through the hinged door, on which the display and so� keys are mounted.
It contains intrinsically safe components such as the sample measurement transducer, pressure sensor
and sample compartment heater.
To ensure the stability of the measurement the transducer is maintained at approximately 65
°C
(149
°F
).
Where fited the pressure sensor is directly a�er the sample measurement transducer and compensates
for both barometric and other pressure changes, i.e back pressure varia�ons when ven�ng to flare
stacks and vent headers.
Where fited the Flowcube (F3) flow sensor is directly a�er the sample measurement transducer,
enabling accurate flow trending and alarm se�ng for many applica�ons including safety cri�cal
applica�ons. The flow sensor offers one high flow alarm and two low flow alarms which can be
configured to be inac�ve or to indicate a fault or maintenance required status via the instrument relay
outputs
or Modbus digital communica�on.
Where
fited sample compartment hea�ng allows samples with dew points of up to 50
°C
to be directly
sampled by the analyser and give greater robustness of the analyser to sample system upsets and
fluctua�ons.
The sample gas inlet and outlet connec�ons on the base of the analyser (see Figure
2
) are piped
into/from this compartment and contain sintered stainless steel par�culate filters, designed to give extra