Precision oxygen analyser offers convenience in biogas measurement

A precise oxygen analyser for continuous monitoring applications, the Parox 2000Plus is an enhanced version of MBE AG’s Parox 2000 paramagnetic oxygen analyser, now featuring an auto-calibration function and an RS232 interface, making it more convenient to operate.  As an option, a flow sensor with alarm settings can be installed.

Described as a simple, accurate and cost effective paramagnetic oxygen analyser, the system can be enhanced with the addition of NDIR units for carbon monoxide, carbon dioxide or methane measurement. It has a wide field of application in ambient, emission and process gas measurements – so it can be used for monitoring biogas, sewer gas, landfill gas, and gases from fermentation processes, as well as for the purposes of establishing toxicity and lower explosion limits.

MBE AG

The device employs the paramagnetic measuring principle (a partial pressure measurement using a rotatable glass dumbbell). The paramagnetic sensor unit itself is thermostat temperature controlled at 55°C. Measuring ranges from 0 – 5 Vol.% O2 up to 95 – 100 Vol.% O2 are available (analogue output: 4 – 20 mA or 0 – 20 mA). When combined with NDIR units for CO (typically 0 – 10 Vol.%),  for CO2 (typically 0.2 to 100 Vol.%) and/or for CH4 (typically 10 to 100 Vol.%), a multi-component analyser can be used.

The instrument is microprocessor controlled with self-diagnosis capability; it is operated by means of a user friendly key pad and a 16-digit LCD display. In addition, the analyser can also be controlled via the RS232 interface (USB or D-Sub).

The programmable auto calibration function together with the integrated relays allow a fully automatic calibration by connecting appropriate zero and span gas. An internal flow regulator, the basis of accurate measurements, guarantees a small and constant flow through the O2 measuring cell while a constant flow between 10 and 90 l/h of measuring or calibration gas is applied at the inlet of the analyser. If an electronic flow sensor is installed, the incoming flow can be monitored and will be displayed together with the concentration value. Furthermore two different alarm relays can be set for supervising the measured concentration.

The Parox analyser is available in various case dimensions, as a 19” rack or table version, as a half 19” portable instrument or in a wall-mounted housing. By adding NDIR units for carbon monoxide, carbon dioxide or methane, the PAROX 2000Plus even becomes a multi-component analyser, the MBE2000Plus. Thus, a wide field of application in ambient, emission and process gas measurements is open. For example, biogas, sewer gas, landfill gas, gases from fermentation processes, toxicity and lower explosion limits. For a landfill application, MBE2000Plus could employ a combination of a built-in PAROX 1200 O2 and a NDIR methane unit.