Troubleshooting: Rapidox 3100

You must prevent water condensing inside the Rapidox as this will eventually damage the sensors. Use a moisture filter or water trap on the gas sample probe if you are working with water-saturated gases (e.g. biogas). Remember that humidity will affect the partial pressures of the other gases to a small degree and their readings will be slightly lower because of this. Please contact Cambridge Sensotec for further advice.

If you are using fresh air to zero the CO2 sensor, then set the zero gas value to 0.04% because there is 0.04% CO2 present in fresh outdoor air. When inside a building it will be considerably higher than this. If you are using a gas bottle (e.g. nitrogen or ‘zero-air’) then set the zero gas value to 0.0%.

It may be that remote diagnostics are able to define possible issues. This service is available through TeamViewer. Please contact Cambridge Sensotec for further advice.

Measuring moisture in gas is a slow process because the sensor surface has to dry out in the measurement gas to give a correct reading. The Rapidox’s internal plumbing collects moisture and, therefore, the analysis is notoriously slow. Please contact Cambridge Sensotec for further advice.

The date, time and other features are user-programmable via the configuration software or front panel, using the built-in configuration menu. When using the software ensure that the time and date are correct on the PC that you are using before attempting to reprogramme the Rapidox. The date format must be set via the software and uses the setting from the PC that was last used to set the date and time. The factory default date format is DD/MM/YY.

Select ‘Default Configuration’ from the ‘File’ menu and load the default ‘rxc’ file from the Rapidox software programme folder on your PC. Alternatively look for the default ‘rxc’ file on your USB, as supplied with the Rapidox. Open this file and then select ‘Write to Analyser’, which will reload the factory calibration. Alternatively you can load a standard default configuration at any time using the ’Load Default’ option from the user menu, which is accessed via the front panel keypad. This is not a permanent configuration for your analyser but it will solve your initial issues. For a long term solution, please contact Cambridge Sensotec for further advice.

Only select ‘Write to Analyser’ once all the values are correctly entered in the boxes on the right of the software window. The best procedure is to ‘Read Analyser Configuration’ and then press ‘Copy’ so that the values in the boxes are the same as those stored within the Rapidox memory. You can then edit these values and then select ‘Write to Analyser’ when finished.

Ensure that you are using the correct cable, as supplied (pin 2 to pin 2, etc.). A crossed RS232 cable (pin 2 to pin 3 etc.) will not work. Validate that your computer recognises your COM ports. Check in your Windows device manager to see if there are any conflicts. If you have an internal modem fixed to your PC, you may experience difficulties using this software. Please contact Cambridge Sensotec for further advice.

Return the Rapidox to the factory defaults using the keypad or communications software. Refer to the instruction manual for further details.

If the room air is very humid, it will affect the observed measurement, or the sensor may have drifted slightly because of natural ageing. If you are using air as a calibration point then simply recalibrate in the air to compensate for this.

Check to make sure which calibration gases are selected. Are they the same as the actual gases that you used to perform the calibration? If not you must recalibrate the analyser or re-load the factory defaults. Please refer to the instruction manual for further details.

If the Rapidox fails to power up, please check that the fuses have not blown. There are standard 20mm 2A slow blow fuses located in the power socket on both live and neutral lines. Replacement fuses are available from various electrical component suppliers. Please contact Cambridge Sensotec for further advice.

The sensor is not designed to measure oxygen above 10,000ppm. If the Rapidox has been switched off for a long time or the internal plumbing has been exposed to an oxygen-rich gas, then please wait a while for the low oxygen gas to flush through. After several minutes, the message should clear, and the Rapidox will resume normal operation.

What kind of gas are you running over the sensor? Does it contain hydrogen or helium? Does the problem disappear if room air is allowed into the Rapidox? If so then the heater may be struggling to warm the sensor with such cooling gases present. If the message continues for approximately eight minutes, then the Rapidox will indicate that the internal heater has failed, and the sensor needs replacing. Please contact Cambridge Sensotec for further advice