Discontinuous oxygen purity measurement
within the expanded range of 99
to 100 volume % O2
?? Portable and rugged instrument, lightweight
??Analogue and digital linear
indication
??Physical meas
PMA50 EEX
Application
Due to the extremely fast response time of the patented M&C magneto-dynamic measuring cell with no stagnant volume as well as the negligible cross sensitivity from other sample gas components, the portable M&C oxygen analyser PMA 10S does not normally limit its use for a wide variety of applications where oxygen purity measurements are essential.
Description
The PMA 10S oxygen purity analyser, being an extended version of the PMA 10, is provided with an electronic suppression system which enables oxygen purity measureents within the expanded 99-100 vol.% range.
This measuring range is displayed on the analogue meter whilst the digital indicator remains for the 0- reading.
The electronic zero suppression system may be selected by means of a push button switch which is located on the control panel of the instrument.
The PMA 10S analyser can normally be used also for its standard PMA10 functions. Oxygen purity measurements could only be made discontinuously. The measuring accuracy of the analyser can be maintained when calibration of the instrument with a certified gas takes place before the measurement procedure in order to avoid influence of ambient temperature and pressure. A measurement of 1 vol.% can be easily realized whilst the maximum value remains at 100 vol.%. Other measurement within this range can be performed.
– Further technical data see leaflet PMA10, 13.1. –
Measuring principle of M&C oxygen analyser
The PMA 10S utilises the paramagnetic principle of operation to measure oxygen concentrations. The analyser measures the paramagnetic susceptibility of the oxygen in the sample gas by means of the M&C magneto-dynamic measuring cell. The physical propertys which distinguishes oxygen from other gases is its paramagnetism. It is significantly higher comparing to other common gases. This operation principle is one of the most accurate and reliable procedures to determine the oxygen concentration in a gas mixture from 0 to 100 Vol.%. The robust M&C cross-flow cell has no stagnant volume. Advantages are the fast response time, the flow rate up to 60 l/hr, the small volume of 2 ml, the extremely low drift, the absolute linearity and the negligible cross sensitivity against other sample gas components. With a proper sample conditioning and pressure, the M&C cell will never need replacing. The dumbbell with a small mirror at its centre is mounted in a strong inhomogenous magnetic field. The paramagnetic oxygen strengthens the forces on the diamagnetic dumbbell and causes a shifting which is detected by a system consisting of light beam, mirror and a photo cell. A compensation current is induced via the feedback coil on the dumbbell and leads to a reset of the dumbbell into its zero-position.
The required current is linearly proportional to the oxygen concentration
