Portable Ethylene Analyzer


Product Details


Please refer to page number 25 in the User Manual.

For continuous mode, we recommend a minimum of 600 mL for a sample. For GC Emulation Mode, the minimum sample volume is 15 mL, but this mode is not as sensitive to low levels of ethylene. The lower detection limit of the F-900 is 40 ppb, or 0.040 ppm when used in Continuous Monitoring Mode. In GC Emulation Mode, the lower detection limit is 0.800 ppm with a range of 0.800 ppm to 20 ppm.

In Continuous monitoring mode, gas enters through the inlet of the device and is drawn in by the pump. The inlet can be free of tubing, in which case it will measure ambient air, or it can be connected by tubing to a chamber or other measurement location or apparatus. In GC Emulation Mode samples are injected into a special port that connects to both the inlet and outlet of the device.

The device will automatically switch between the PPB and PPM level ethylene sensors depending on the measurement level that it is currently reading and the slope of the change in reading. The automatic switching threshold is about 2.5 ppm. Each sensor can also be manually shut off prior to measurement.

There are common, everyday sources of ethylene that can be picked up on by the sensors in your Felix Gas Analyzers. Common sources of ethylene include smoke or exhaust. Furthermore, the ethylene sensors inside of the Felix Gas Analyzers are also sensitive to various volatile organic compounds (VOCs). Various cleaning agents are often a source of VOC readings. If you are inside, it is not uncommon for the ethylene sensors to report readings between 0-0.5ppm of ethylene. If you are outside, drawing clean ambient air (away from traffic, smoke, or other sources of exhaust) it is more typical to see 0.0 ppm readings for ethylene.

The 16GB card provided with the F-9xx gas analyzers technically has indefinite storage capacity as the files can be moved off the card to reopen storage space. However, without moving any files off the card, it can hold up to ~60 million measurements from a F-9xx analyzer. If the instrument is saving data every minute that equates to ~40,000 days of measurement before the SD card is full.

  1. Open up the desired manual in a browser window 
  2. Click ‘Accessibility Mode’ 
  3. Select the download icon. The manual will download as a pdf. 

I don’t feel that my F-9xx Gas Analyzer is reading accurately, what should I do?

When communicating with support it is helpful to provide: 

  1. Serial number and firmware version on the instrument 
  2. Send the sensor parameter file (.config file) found on the SD card by doing the following: 
  3. Navigate to setup > factory setup 
  4. Select ‘backup’. The instrument will store a backup file of the current configuration file.  
  5. Send this config file with the day’s date to 


If your analyzer is less than three months old, see the two options below: 

  1. Try restoring the factory defaults on the device  
  2. Navigate to setup > factory setup 
  3. Select ‘restore’ and restore the parameter file containing the calibration set at the manufacturers facility 
  4. Perform a baseline calibration on the sensors 

Perform a set zero calibration on the sensors using the external conditioning chamber filled with potassium permanganate for the ethylene sensor and the external conditioning chamber filled with soda lime for the CO2 sensor. Use the O2 calibration in air menu option to calibrate the O2 sensor using ambient air. Only use the O2 set zero setting if you are using 100% nitrogen gas.  

Please see the user manual for more details.  

If your analyzer is over three months old, see options below: 

If your instrument is over three months of age, inaccurate sensor readings could indicate a need for calibration. You can try a baseline calibration (or set zero) of the sensors first and if this does not bring the readings into spec, then perform a full calibration.  

Please see ‘How Do I Calibrate the Instrument?’ FAQ for more details.  

  • Navigate to the manual you wish to translate (available in our support section).
  • Once the manual is open, select the contextal menu by selecting the "..." option in the upper-right hand corner of your screen.
  • Select the translate option (as shown above).
  • Select your preferred language. Select translate.

Note: Due to limitations of Microsoft Translate, manuals greater than 50 pages in length currently do not support dynamic translation.

First, we need to set the internal volume of the unit in accordance to which sensors are present.

  • Setup > Calibration > Injection Parameters
  • Set internal volume according to which sensors the unit is equipped with
    • C2H4 Only – 22.5
    • C2H4, O2 & CO2 low-resolution – 27.5
    • C2H4, O2, CO2 low-resolution & CO2 high-resolution – 39.0
    • C2H4 & CO2 high-resolution – 37

Next, we will calibrate the unit using the following formula:

Calibrated Volume = (Sample concentration * Sample volume) / GC Emulation Result

**Please note that it is absolutely imperative that the analyzer have all sensors properly calibrated before continuing.**

  • We recommend C2H4 concentrations of 2000ppb and 75ppm (10mL) for GC Emulation calibration
  • When calibrating for PPB disable the PPM sensor and vice versa
  • Navigate to Setup > Measure > Mode and select ‘GC Emulation’
  • Return to the main menu and select ‘Measure’
  • Follow the on-screen instructions, including attaching the ‘injection port kit’ and entering in the volumes of your ppb and ppm samples
  • After a stabilization and pre-processing period, the unit will take 75 seconds to analyze the provided sample
  • Once complete, take note of the C2H4 and flow values. The C2H4 value represents the ‘GC Emulation Result’
  • Enter the values provided into the above formula to calculate the ‘calibrated volume’ value
  • Enter the ‘Calibrated Volume’ value under Setup > Calibration > Injection Parameters
  • Repeat the process for the other C2H4 sensor (PPM or PPB)

The temperature and relative humidity sensor is located inside the F-900, before the electrochemical sensor. There is an additional relative humidity sensor after the ethylene sensor to help track water loss.


1-MCP is short for 1-Methylcyclopropene. This is a synthetic plant growth regulator, which is structurally related to ethylene (natural plant hormone). When applied to fruit, 1-MCP binds to ethylene receptors without triggering the signal cascade that leads to climacteric ethylene biosynthesis and ripening. Commercially, it is used to slow down the ripening of fruit and to maintain the freshness of cut flowers. The chemical formula is C4H6.


The unit has an SD card and the format can be read on any Mac or PC. Data can also be downloaded via USB. The F-900 Controller software is used when connecting to a PC to view real-time data. 

Both are portable, but the research kit includes the other components shown on the website, such as the fruit chamber and wand and hard-sided carrying case. The Research Kit is designed to make measurement of fruits on a tree (non-destructively) more convenient. A fan is built into the chamber to mix the air around the fruit.

If data isn't displaying properly, try saving the file as a .csv file type and re-opening it. If saving as a .csv does not fix how the data is displayed, you may need to change the separator value on your computer.

To change the separator in all .csv text files:

    1. In Microsoft Windows, click the Start button, and then click Control Panel.
    2. Open the Regional and Language Options dialog box.
    3. Do one of the following:
      1. In Windows Vista and 7, click the Formats tab, and then click Customize this format.
      2. In Windows XP, click the Regional Options tab, and then click Customize.
    4. Type a new separator in the List separator box. For example, type ","
    5. Click OK twice.

NOTE: After you change the list separator character for your computer, all programs use the new character as a list separator. You can change the character back to the default character by following the same procedure.

There is a protective hydrophobic filter inside the IN port on the front of the F-900. This will prevent moisture from fully entering the instrument. Silica gel in a conditioning chamber can be used to dry out the gas stream, either before or after the gas passes the electrochemical sensor. Refer to the flow path diagram in the Setup>Chamber section of the User Manual for more information. 

  • The F-900 and F-900RK ship with a humidity scrubber (silica gel) and an ethylene scrubber (Purafil Fresh Air Sachets).
  • If the F-900 includes the optional CO2 sensor, a jar of CO2 scrubber (soda lime) is provided. Please contact Felix Instruments technical support with any questions.

Climacteric fruits refer to fruits that have high respiration rate during the fruit's ripening. During the ripening process of climacteric fruits, the production of a phytohormone, ethylene, dramatically increases up to 1000-fold of the basal ethylene level. Climacteric fruits are ones that are able to ripen after being picked. An example of climacteric fruit is bananas; they are picked and shipped green and then ripen at a later time (often in the store or home). Climacteric fruits include, but are not limited to, apples, apricots, avocados, bananas, cantaloupes, figs, guavas, kiwis, mangoes, nectarines, peaches, pears, persimmons, plums, and tomatoes. [Source:]

  • The F-900 could be used to help optimize Controlled Atmosphere Storage Rooms and prevent losses. Ethylene is an important and sensitive marker for ripening of fruits. Other postharvest research applications are possible.
  • In addition to plants, some microorganisms, including fungi and bacteria, synthesize ethylene. Microorganisms can cause great losses in the postharvest industry through disease and mold, so research into ethylene and the pathogen-host interaction is important. A common plant pathogen that produces ethylene is Botrytis cinerea.
  • Measuring ethylene concentration in the air of rooms where young apple trees in pots are stored adjacent to refrigerated apple storage rooms, in order to assess the safety to young apple trees. During the winter months, the safe level for storage of first year apple trees is below 50ppm.
  • Commercial apple growers could monitor the ethylene levels of empty refrigerated rooms before storing bare-root nursery trees. Rooms should be empty of ethylene before storing nursery trees and often growers have no way to monitor this.
  • Monitoring ethylene emission from industrial sources. Ethylene is of interest because it plays a role in atmospheric ozone chemistry. This will be dependent on interfering gas and the source of industrial emissions.

To start using the F-900, you need to create a file to save data into. Go to File<Create. Change the file00 to the desired file-name and press save. Next, open the file to save measurements. Go to File<Open and use the arrows to highlight the newly created file. If the value next to the file-name is a negative number, this indicates an error. You should delete the file and create it again. Then, open it and check that the value is zero. Now, you can save data into this file.

Several types of material have been found to outgas interfering gases of the ethylene sensor, such as Tygon.  Viton and Teflon have successfully been found to not outgas. 

Both chambers are optional, but it is recommended to use Chamber In as PolarCept for most measurements.  The most common use for Chamber In is to separate light hydrocarbons, such as alcohol, from the gas stream which may interfere with the measurement.  The most common use for Chamber Out is to be filled with potassium permanganate, so that it cleans all ethylene and other hydrocarbons from the gas stream, so that any ethylene that is measured must have come from the sample. Chamber OUT is also commonly used with KMnO4 to calibrate the zero of the ethylene sensors.