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Cambridge Sensotec Rapidox 1100ZR-H-PFC-E O
2
Analyser Instruction Manual
Version 1.2
16
Last printed 22/07/2015 18:08:00
absolute). To access this function scroll down to menu option 7 “Pressure Mode”
and press ENT. The desired mode can then be selected using the UP & DOWN
arrows and pressing ENT to store and proceed. The two modes available are:
1.
None
:
If this mode is selected then there is no pressure correction
performed on the oxygen reading. The pressure and oxygen sensor act
independently. If the sensor is working in air (20.95%) and the pressure is
doubled to 1000 mbar then the reading will also double to 41.9%. This is
the correct oxygen partial pressure in air at 2 bar since there is a simple
linear relationship between pressure and concentration.
2.
Auto
:
This is the factory default setting. If the Auto mode is selected then
the Rapidox uses the reading from the internal pressure sensor to correct
the oxygen partial pressure and maintain a concentration reading. If the
sensor is working in air (20.95%) and the pressure suddenly jumped to, for
example, 500 mbar above atmospheric, the oxygen reading would remain at
20.95% because the sensor has been corrected for the pressure change.
This allows users who are working with fluctuating input pressures to
maintain a ‘meaningful’ reading of oxygen concentration that will only be
affected by changes in gas composition and not gas pressure.
Note that when this mode is activated the user will be asked to enter a value for
the current ambient pressure to slightly improve the accuracy of the correction.
The factory default is 1013mbar which is the average ambient pressure for the UK.
The ambient pressure at your location will depend on altitude and prevailing
weather conditions.
7.13
Setting the Baud Rate
If you are using the software for data logging you can chose the communications
speed (Baud Rate) by scrolling down the menu to no. 8 “Baud Rate” and using the
UP & DOWN arrows to select either 9600 or 57,600. Press ENT button again to
store and return to normal operation. The default factory setting is 57,600.
However if you are using an older PC you can decrease this to 9600 to improve the
reliability of the software and data communications.
7.14
RS232 / RS485 Port
It is possible to factory set the data communications port to either RS232 or
RS485. Once configured at the factory it is not possible to change unless the unit
is returned to Cambridge Sensotec Ltd. Data from the Rapidox is sent on demand
to the 9-way 'D' type socket (8) on the rear panel and can be read using a simple
terminal programme such as 'HyperTerminal' in Windows, or with the user's own
custom software. Alternatively a simple and convenient data logger programme is
included with the supplied software and is described in section 9 below.