The micro-oxygen meter has a too large error compared to the manual value
Thread Content
Process: Pressure swing adsorption; Equipment manufacturer: Shanghai Ruiqi. Problem description: In August 2019, the nitrogen production system was shut down due to a reduction in the amount of nitrogen used by the upstream units. Before shutdown, the production rate was 800–900 standard cubic meters per hour, with a purity level of 99.98%. After it was restarted a month later, the purity level fluctuated between 91% and 96%, and these fluctuations became more pronounced as the flow rate increased; the lowest purity level reached 99.89%. The sealings of the exhaust valves in both towers were damaged, and they were replaced today. The purity sensor as well as the micro-oxygen detector were also replaced. After these replacements, when the system was started up, the purity level was 99.98% at a production rate of 400 standard cubic meters per hour, with a micro-oxygen level of 400 ppm. However, manual analysis indicated a level of 800 ppm. What could be the reason for this, experts?
Manual sampling may result in higher values in trace analysis, while online instruments can use standard gases to check for any deviations.
There is a significant difference between manual analysis and instrument-based testing; it is recommended to send the micro-oxygen meter for calibration, so that the oxygen content can be measured accurately thereafter.
Okay, thank you. I’ll prepare a standard sample this afternoon
Okay, thank you. I’ll prepare a standard sample this afternoon