In This Video we will see step by step procedure how to do manual zero calibration for AO 2000 Model The zero should be calibrated manually prior to a manual span calibration. Test Gas Supply If the test gases enter at the zero or span gas input, the test gas supply is controlled by the integral valves. If the test gas enters directly via the sample gas inlet, the zero and span gases must be blocked off. It may be necessary to repeat calibration if the measurement value is still not stable after calibration has been started. The subsequent process is based on the measurement value obtained in the previous calibration. Stay connected with our social media pages: Instagram : https://www.instagram.com/analyzerinstruments/ Telegram : https://t.me/analyzer_Inst twitter : https://twitter.com/Analyzer_inst LinkedIn : https://www.linkedin.com/groups/8225482/ Facebook page : https://www.facebook.com/AnalyzerInstruments Blog