IM3 Automatic Calibration Procedure

Before starting a calibration, procure the required calibration gases, compressed nitrogen for zero calibration, and a certified CO2 span gas. Connect the gases to the nitrogen and the CO2 span gas ports on the front of the CGF. Access the IM3 software by entering the system’s unique URL in a browser search bar. Verify that the system is ready and on standby. Check the configuration page and verify that the system is set up appropriately. In this case, it’s set up to run a treadmill on bank B.

Next, open the status page to assess the gas analyzers. Make sure the oxygen, the CO2, and the water vapor sensors all measure within range, indicated by the green status. And do the same for the main flow rates. Next, click to open the Utilities menu. Then select Gas Analyzer Auto-Calibration. From the Auto-Calibration page, enter the CO2 span gas value in the window. In this case, it’s 0.0922%. Verify the span gas value on the cylinder’s calibration certificate, 0.922%. For this video, we’ll select short zero and both span CO2 and span oxygen. That’s all that’s needed to set up the Auto-Calibration.

Next, click Start Auto-Calibration to begin the procedure. The message window will periodically update to display the steps during the Auto-Calibration. In preparation for zero calibration, the calibration path is flushed with nitrogen. Then nitrogen is passed through the analyzers. Now the system waits for the sensors to equilibrate to the pure nitrogen. The progression of this procedure can also be viewed on the real-time graphs. Select the CO2 analyzer on bank B. The real-time graph shows the start of the calibration and the nitrogen entering the analyzer. The O2 analyzer shows a similar progression. And so does the water vapor analyzer. All converge on zero. Zero equilibration takes about 10 minutes, and in the interest of time, we’ll speed this up.

Once the system has reached a reliable equilibration value, it applies a zero value to each of the analyzers. Then a flush valve opens to replace all of the nitrogen from the calibration path with ambient air. This takes about 15 seconds. Next, the calibration path is flushed with CO2 span gas. The real-time graph reveals an increase in the CO2 values, beginning at zero to ambient and then to the span gas concentration, 0.922%. O2 measures return briefly to ambient values before dropping to zero due to the anoxic CO2 span gas. Water vapor behaves similar to the O2 measures. The message window shows that the system is waiting to equilibrate to the value of the CO2 span gas. All of this is reflected in the real-time graph.

CO2 span equilibration takes about five minutes. And again, for the interest of time, we’ll speed this up. After five minutes, the CO2 span is applied, the calibration path is then flushed, and ambient air is measured to set the O2 span value. Here, the real-time graph shows how CO2 drops from the span level back to the ambient concentration, in this case, 0.0435%. O2 and water vapor also return to ambient values. O2 span equilibration takes about ten minutes. We will again speed up this process for you. After ten minutes, the O2 span is completed, the calibration path is then flushed, and the system indicates a successful calibration.

After the calibration, we can check the status page again. The analyzers, specifically O2, now shows corrected values of 19.15%, compared to the previous value of 20.34%. Your system is now ready to collect accurate data. Thank you.