Fixed Volume Mode
To begin, the unit should be disconnected from the sample of interest while the sensors purge, stabilize and equilibrate to the ambient environment. The instrument will purge for 5 seconds to remove the previous sample from the internal tubing of the instrument. If additional time is required, press the Right arrow to start the purge cycle again. Once stable, the instrument will prompt the user to connect the sample and press start to begin measuring.
Assemble the probe by connecting the “Fixed Volume Needle Probe” black tubing to the intake of the F-950. Next, twist on a hydrophobic filter to the end of the tubing. The filter will prevent any moisture or debris from being sucked into the instrument. Finally, attach a sterile needle to the filter. Depending on the application, needles can be re-used.
After the start button has been pressed, the pump will run until the sample volume (default: 15 mL) has been drawn into the F-950, and then the loop will close while the sample is analyzed. Maximum sample volume in fixed volume mode is 18.5 mL. Minimum sample volume is 10 mL for 5-10% accuracy.
When the loop is closed the F-950 system should be disconnected from the sample. The unit will read “Processing… after the fixed volume is drawn inside the unit. Once processing is seen on the display, disconnect from the sample while the sensors analyze the fixed volume sample and provide the results.
The final result is then displayed on a new screen. The values listed are the concentrations of C2H4, CO2, and O2 present in the sample. To the right of the concentrations, are the relative humidity, temperature, volume of sample, and duration to collect and analyze sample.
Press the start button to return to the measurement screen. Connect to the next sample and press the start button to begin another measurement.