Cambridge Sensotec Rapidox 1100ZR-H-PFC-E O
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Analyser Instruction Manual
Version 1.2
44
Last printed 22/07/2015 18:08:00
distinguish it from HW as in ‘HW Alarm Config’ which is the programming of the
physical alarm relays on the back of the analyser.
11.3
Prop. Flow Control tab
Figure 25: PFC configuration page
The on-screen edit boxes below the button labelled ‘write’ contain PFC variables
that can be reprogrammed into the Rapidox. The user can choose whether to use
ppm or percent notation to edit the text boxes, where appropriate, by selecting the
‘UNITS’ menu and clicking on ‘percent’ or ‘ppm’. To access a field, either click
inside it or use the TAB key to scroll through them. The field parameters are as
follows:
25)
Flushing Flow (%):
This parameter is used to set the initial flow of gas
through the valve during the warm up cycle of the Rapidox (typically four
minutes). It is normal in this stage to have the nitrogen gas valve opened to
its maximum to allow the oxygen level to be reached as quickly as possible.
The value is entered in terms of a percentage (0-100%) where 0% means the
signal is 4mA and the valve is fully closed, and 100% means the signal is
20mA and the valve is fully open. A typical setting would be 99%, but in
this release of the software the parameter is not yet functioning so please
ignore for the time being.
26)
O
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Regulation High Point:
The units of oxygen are displayed alongside the
text. Use the “Units” menu to change from % to ppm as you wish. This
parameter sets the upper limit of the target window O
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value. In order to
prevent the gas valve opening and closing excessively and wearing out, the
PFC operates around an upper and lower O
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value which defines the PFC
window. Inside the window the PFC stops adjusting the gas valve and
waits for the gas reading to creep outside the window region again. At this