Felix Storch F-900 User manual

DECLARATION OF CONFORMITY
Manufacturer:
CID Bio-Science, Inc.
1554 NE 3rd Ave
Camas, WA 98607
Declares that the CE-marked Product:
Product Model(s):
Model F-900
FCC Compliance Statement:
This device complies with part 15 of the FCC Rules. Operation is subject
to the following two conditions: (1) This device may not cause harmful
interference, and (2) this device must accept any interference received,
including interference that may cause undesired operation.
Complies With:
89/336/EEC Electromagnetic Compatibility Directive
73/23/EEC Low Voltage Directive
Compliance Standards:
EN 55027 RF Emissions Information
Technology Equipment
EN 50082-1 EMC Immunity Standard
EN 60950 Safety of Information
Technology Equipment Including Electrical Business Equipment
December 18, 2013
Leonard Felix
President

Contents
Introduction.................................................................................................................................................. 1
Features................................................................................................................................................... 2
Specifications.......................................................................................................................................... 3
Warnings...................................................................................................................................................... 5
Theory of Operation................................................................................................................................... 6
Interfering Gases.................................................................................................................................... 7
PolarCept................................................................................................................................................. 7
PolarCept: Measure........................................................................................................................... 8
PolarCept: Clean................................................................................................................................ 8
Unpacking the F-900 ................................................................................................................................. 9
F-900 Research Kit Accessories........................................................................................................ 10
Operating Instructions ............................................................................................................................. 11
Charging the Internal Battery ............................................................................................................. 12
F-900 CO2PPM Sensor and Battery Power................................................................................ 13
Measure Menu: Taking a Measurement............................................................................................... 14
Sensor Stability..................................................................................................................................... 14
Graph Mode.......................................................................................................................................... 14
Monitor Mode........................................................................................................................................ 15
Measurement Settings......................................................................................................................... 17
Notes About Measurements with the F-900..................................................................................... 17
Electrochemical Sensor Response................................................................................................ 17
Auto-Escape Feature....................................................................................................................... 18
Flow Block Error............................................................................................................................... 18
No SD card Present......................................................................................................................... 18
F-900RK: Using the Research Kit Fruit Chamber........................................................................... 18
GC Emulation Mode............................................................................................................................. 21
How GC Emulation Mode Works................................................................................................... 21
GC Emulation Mode Operation Procedure .................................................................................. 22
F-900 Calibration...................................................................................................................................... 25
Pre-requisites........................................................................................................................................ 25
Standard Operating Procedure.......................................................................................................... 27

Ethylene Sensors................................................................................................................................. 28
Ethylene PPB Sensor...................................................................................................................... 28
Ethylene PPM Sensor ..................................................................................................................... 28
CO2 Sensors......................................................................................................................................... 28
CO2 PPM........................................................................................................................................... 29
CO2 PCT........................................................................................................................................... 32
O2............................................................................................................................................................ 32
Ethylene Sensor Zero Calibration ......................................................................................................... 33
Manually Set Zero: Standard Operating Procedure........................................................................ 33
Manually Set Zero: PolarCept Enabled ............................................................................................ 34
Automatically Set Zero: Offset Correction........................................................................................ 34
F-900 Menu System Diagram ............................................................................................................... 36
Setup Menu............................................................................................................................................... 37
Setup Measure ..................................................................................................................................... 37
Setup Autosave.................................................................................................................................... 37
Setup Sensor........................................................................................................................................ 38
Setup Calibration.................................................................................................................................. 39
C2H4Calibration................................................................................................................................ 39
Offset Correction.............................................................................................................................. 40
Flow Rate Calibration...................................................................................................................... 41
Setup Time and Date........................................................................................................................... 41
Setup Flow ............................................................................................................................................ 41
Setup Chamber..................................................................................................................................... 42
Setup Terminals ................................................................................................................................... 45
Setup Board...................................................................................................................................... 47
View Menu................................................................................................................................................. 49
View Files.............................................................................................................................................. 49
View Voltage......................................................................................................................................... 49
View Battery.......................................................................................................................................... 50
Other View Menu Options................................................................................................................... 50
GPS System Features..................................................................................................................... 50
File Menu................................................................................................................................................... 52

Clear a File............................................................................................................................................ 52
Delete a File.......................................................................................................................................... 52
Create a File.......................................................................................................................................... 53
Open File............................................................................................................................................... 53
Data Transfer to a Computer.................................................................................................................. 55
Data Files .............................................................................................................................................. 55
Wireless SD Memory Card Operation............................................................................................... 57
Firmware Update...................................................................................................................................... 60
G.A.S. Gas Analysis Software ............................................................................................................... 64
Technical Support.................................................................................................................................... 70
Frequently Asked Questions .............................................................................................................. 71
Supporting Sciences References ...................................................................................................... 75
APPENDIX I: Procedure for F-900 Validation Using Fruit................................................................. 77
Method 1: Sampling with No Filtration/Trapping ............................................................................. 77
Method 2: Sampling with Filtration/Trapping.................................................................................... 77
Method 3: Long-Term Monitoring with Filtration.............................................................................. 78
APPENDIX II: Guidelines for Measuring Sample Bags...................................................................... 79
To Collect a Sample Using a Sample Bag................................................................................... 79
Analyzing a Sample Bag with the F-900....................................................................................... 80
APPENDIX III: 8L Chamber Accessory................................................................................................ 81
APPENDIX IV: F-900 Controller Software for Calibration.................................................................. 82
Ethylene Sensor Span Calibration..................................................................................................... 82
Set C2H4PPB Span......................................................................................................................... 82
APPENDIX V: Guide for Purchasing Standardized Gases for Calibration...................................... 86
F-900 Production Test Check Sheet..................................................................................................... 88
Warranty Information............................................................................................................................... 89
This instruction manual is written for firmware version 4.7.X.X

F-900 Instruction Manual 8/14/2017
1554 NE 3rd Ave, Camas, WA 98607, USA Phone: [phone]
www.felixinstruments.com
Introduction
Congratulations on the purchase of your new F-900 Portable Ethylene Gas Analyzer. The F-900
provides accurate real-time measurement of ethylene gas concentrations in a compact
instrument suitable for field and laboratory use. At the core of the instrument is an
electrochemical sensor that offers extraordinary sensitivity to ethylene, at levels as low as 0.025
ppm (25 ppb) in air.
Ethylene production is known to increase in response to plant stress and during fruit ripening
and maturity, and until recently, sensitive ethylene measurements were available only through
elaborate and expensive gas sampling and gas chromatography analysis. The intent of the F-
900’s portable design is to aid the research community in developing real-world ethylene
management applications for the benefit of growers, processors, and consumers.
The F-900 employs electrochemical sensors as well as several other sensors for temperature,
humidity, GPS location, and optionally carbon dioxide (CO2: high and low range) and oxygen
(O2). During a sample, the subject gas travels across the surface of the electrode and diffuses
into the electrochemical cell where ethylene is oxidized. The current created by the oxidation is
measured and interpreted as the concentration of ethylene (reported in parts per million or
ppm).
We hope you enjoy using your F-900 Portable Ethylene Gas Analyzer.
Figure 1: The F-900 Portable Ethylene Analyzer front panel and display.

F-900 Instruction Manual 8/14/2017
1554 NE 3rd Ave, Camas, WA 98607, USA Phone: [phone]
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Features
High sensitivity to C2H4 (0 ppm –200 ppm)
CO2 and O2sensing capability (optional)
Compact portable form factor (2.96 kg)
Real time continuous monitoring
Internal data logging and storage
Automatic data logging with adjustable interval
User adjustable flow rate
Transflective display enables easy viewing in direct sunlight
Rechargeable Li-Ion battery provides 5 hours of monitoring in the field
Multiple configurations to accommodate in situ research and controlled atmosphere
monitoring
Instantaneous and accumulated measurement modes (Monitor and Graph View)
Quick connect sampling ports
Data saves in .csv (commas separated value) file
Configured for domestic and international operation: 110 VAC, 60 Hz or 230 VAC, 50 Hz
Non-destructive measurements
Mini-USB chargeable and mini-USB data download
Time-date stamped data records
External wire terminals for fixed location monitoring or control applications
GC Emulation Mode for small sample volumes ranging 0.8 –20 ppm C2H4(optional)
Figure 2: The removable SD card on the F-900 makes data transfer quick and simple.

F-900 Instruction Manual 8/14/2017
1554 NE 3rd Ave, Camas, WA 98607, USA Phone: [phone]
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Specifications
F-900 Specifications
Display
Sunlight visible transflective graphic LCD
Operating environment
0°C - 45°C (0-90% humidity non-
condensing)
Battery Capacity
5-8 hours - Rechargeable Li-Ion (5000
mAh)
Dimensions
183.5mm x 111 mm x 120 mm
Weight
2.96 kg
Enclosure
Anodized aluminum
Typical air Sampling Rate
80 mL/min
Measuring Rate
1 second intervals, open or closed loop
Warm-up time
1 minute
C2H4PPB Sensor
Electrochemical
Nominal Range
0- 10 ppm
Resolution
0.001 ppm
Lower Detection Limit
0.025 ppm (25 ppb)
Accuracy
5% ± 25 ppb
Offset Recalibration
Weekly
Span Recalibration
*3 months (calibration gas required)
C2H4PPM Sensor
Electrochemical
Nominal Range
0- 200 ppm
Resolution
0.1 ppm
Lower Detection Limit
0.5 ppm
Accuracy
±5 % ±0.5 ppm
Offset Recalibration
weekly
Span Recalibration
*3 months (calibration gas required)
*typically < 5% drift/month
GC Emulation Mode Specifications
C2H4 Range
0.8-20 ppm
Accuracy
±10 %
Minimum Sample Volume
5 mL

F-900 Instruction Manual 8/14/2017
1554 NE 3rd Ave, Camas, WA 98607, USA Phone: [phone]
www.felixinstruments.com
Optional Sensors
CO2PPM Sensor
Low-Power Non-Dispersive Infrared Gas
Analyzer
Chopping Frequency
1Hz
Source Life
5000 Hours
Nominal Range
1 –2000 ppm (Standard)
Resolution
0.1 ppm
Repeatability
±0.1 ppm (short term)
Accuracy
5%
Sample Cell
100 mm x 10.2 mm (3.94" x 0.4" diameter)
Warm-up time
<3 minutes
Weight
172.6 g
Offset Recalibration
Weekly
Span Recalibration
6 months (calibration gas required)
CO2Percent Sensor
Infrared Sensor, Pyroelectric detector
Nominal Range
0 –20%
Resolution
0.01%
Accuracy
5%
Offset recalibration
6 months
Span recalibration
6 months (calibration gas required)
Lifetime
>5 years
Warm-up time
<3 minutes
Weight
7 g
O2 Percent Sensor
Electrochemical
Nominal Range
0-100%
Resolution
0.1%
Offset recalibration
6 months
Span recalibration
6 months (calibration gas required)
Operating environment
0°C - 55°C (5-95% humidity non-condensing)
Weight
7 g

F-900 Instruction Manual 8/14/2017
1554 NE 3rd Ave, Camas, WA 98607, USA Phone: [phone]
www.felixinstruments.com
Warnings
Read this manual carefully before using: this manual should be read by anyone who will
be operating the F-900. By following the guidelines, the F-900 will function according to
the specifications in this instruction manual.
All repairs should be performed by a Felix Instruments technician.
The analyzer must be used to measure the rate of ethylene in the presence of nitrogen,
oxygen and carbon dioxide. All other gases in high concentration could lead to
erroneous measurements, or the destruction of the sensor. Do not use the instrument in
the presence high concentrations of aromatic solvents, hydrocarbons or other volatile
organic compounds, such as in unventilated painting rooms or chemical storage rooms.
Damage to the analyzer can occur if the fluid reservoir level is too low or if the inlet and
outlet gas connections are blocked while the pump operates. This can cause false
readings or irreparable damage to the sensor.
Use a T-valve when connecting the F-900 to a standard gas tank
If smoke comes out of the analyzer, turn off the power immediately and contact Felix
Instruments-Applied Food Science.
Keep the analyzer in a clean and ventilated room at ambient temperature.
Do not allow fluid to aspirate in the analyzer, which can destroy the sensors.
Do not use the F-900 in a high RF (radio frequency) environment. High RF will disrupt
the F-900.
ESD (electrostatic discharge) interferes with the F-900 measurement data.
Do not tilt the F-900 when Chamber IN contains water
Do not fill Chamber IN beyond max fill line
Do not use KMn04 ‘dust’. Only the ‘bead’ format is suitable for Chamber IN.
WARNING: Do not store the F-900 without charged batteries! The internal batteries
must have charge to maintain the accuracy of the sensors, even when the unit is
powered off. It is recommended to keep the instrument connected to the power
supply for long term storage.

F-900 Instruction Manual 8/14/2017
1554 NE 3rd Ave, Camas, WA 98607, USA Phone: [phone]
www.felixinstruments.com
Theory of Operation
The ethylene sensors in the F-900 are electrochemical. With this type of sensor, the gas sample
travels across the surface of the electrode and diffuses into the electrochemical cell where
ethylene is oxidized. The current created by the oxidation is measured and converted to parts
per million (ppm) of ethylene.
Figure 3: Diagram of an electrochemical sensor. (A) working electrode (R) reference electrode
(C) counter electrode (E) electrolyte. Image credit: doi:10.1093/aob/mcs259.
The F-900 flow rate is regulated by a pump and a flow meter. Additional optional sensors are
enabled/disabled in the Setup Menu (see page 40), as well as “conditioning chambers” on the
back of the instrument (see page 45).
The temperature and relative humidity sensors are located inside the instrument. Therefore, the
temperature sensor is subject to heating by the F-900 internal electronics. The temperature
reading is often 4-5OC above ambient and in turn, relative humidity readings are affected. The
use of water in Chamber In (PolarCept, see page 8), will also affect relative humidity readings.

F-900 Instruction Manual 8/14/2017
1554 NE 3rd Ave, Camas, WA 98607, USA Phone: [phone]
www.felixinstruments.com
Figure 4: Flow path diagram of the F-900 ethylene analyzer. Dashed line indicates optional flow
path capabilities.
Interfering Gases
No analytical method is completely specific. Gases present in the environment, other than the
target gas of a measurement, may affect instrument response. Interferences are not necessarily
linear, and may also exhibit time dependent characteristics.
Ripening fruit emits a complex mixture of hydrocarbons, including ethylene. Oxidation of these
other gases in the electrochemical sensor cannot be readily distinguished from ethylene. This
causes the ethylene value to be falsely high in the presence of interfering gas. Felix Instruments
has tested a method to absorb some of the competing gases and provide better ethylene
measurements. This method, PolarCept, uses distilled water in conditioning Chamber In and
has been shown to filter out alcohols and produce less interference.
PolarCept
PolarCept is the use of distilled water in conditioning Chamber In to filter out or trap some of the
interfering gases. Gas from the sample environment is passed through the water trap. Some of

F-900 Instruction Manual 8/14/2017
1554 NE 3rd Ave, Camas, WA 98607, USA Phone: [phone]
www.felixinstruments.com
the polar molecules are held in the trap, while ethylene passes through the water trap to the
sensor, where oxidation occurs. CO2is released as the oxidation product from the sensor. The
water being used can become saturated after several minutes, so it must be cleaned of the
trapped interfering gas molecules. Trapped interfering gases are driven out of the water during
the cleaning time by a concentration gradient.
It is recommended to always use the PolarCept filter when measuring a gas mixture or
interfering gases present will be reported by the instrument.
Alcohols can induce a baseline shift and/or change the sensitivity of the ethylene sensor. To
recover the sensor after exposing it to alcohols, run it with clean air for a few days.
NOTE: Unless using ultra-pure DI water, the water used for PolarCept will likely contain
impurities. Before using PolarCept, it is important to perform a manual set zero of the ethylene
sensors with Chamber In enabled. For more details on this process please refer to the ethylene
sensor zero calibration, starting on page 35.
PolarCept: Measure
Regeneration: cleans the water
PolarCept: Clean
Figure 5: Top: diagram of measure period during use of PolarCept. Bottom: diagram of cleaning
period of PolarCept.

F-900 Instruction Manual 8/14/2017
1554 NE 3rd Ave, Camas, WA 98607, USA Phone: [phone]
www.felixinstruments.com
Unpacking the F-900
The F-900 base unit arrives with the F-900 and several accessory parts to use with the
instrument. Included are the heavy duty USB cable, charger, tubing accessory kit, potassium
permanganate (KMnO4) and an F-900 Instruction Manual. Several different styles of connector
pieces and various lengths of tubing that do not outgas (ex: Viton or Teflon) are provided as
part of the tubing accessory kit. Male and female quick connectors can be added to tubing and
used to connect sample bags or custom chambers to the F-900.
Figure 6: Accessories and parts that arrive with the F-900, clockwise from top center: F-900
ethylene analyzer, power supply and heavy duty USB cable, Viton tubing, Teflon tubing with
quick connects, assorted quick connects.
The F-900 includes the consumable potassium permanganate (KMnO4), which is used to scrub
ethylene and other hydrocarbons from the gas stream. If the instrument has an optional CO2
sensor, soda lime is included, which is used to scrub carbon dioxide from the gas stream and to
create a 0 ppm CO2gas for the CO2zero calibration.

F-900 Instruction Manual 8/14/2017
1554 NE 3rd Ave, Camas, WA 98607, USA Phone: [phone]
www.felixinstruments.com
F-900 Research Kit Accessories
The F-900 Research Kit (F-900RK) includes parts to non-destructively sample fruit in the field or
laboratory. The F-900RK arrives in a hard-sided carrying case with a fruit chamber and wand
with flexible tubing to sample fruit or plants. The fruit chamber includes a closed chamber lid
and a lid with a seal to allow sampling of fruit still intact on the plant. The F-900RK includes all
the parts and accessories that arrive with the F-900, as well as an external conditioning tube,
sample bag, injection port assembly, glass syringe, needle, and a jar of silica gel which can be
used to dehumidify the gas.
For information on the 8L fruit chamber, please see appendix IV.
Figure 7: The F-900RK arrives with a fruit chamber and two lids: closed chamber lid (left)
and slit chamber lid (right).

F-900 Instruction Manual 8/14/2017
1554 NE 3rd Ave, Camas, WA 98607, USA Phone: [phone]
www.felixinstruments.com
Operating Instructions
To turn the instrument on, press the green power button. The top of the display reads F-900 and
the current firmware version the unit is running. For information on the latest firmware version,
please visit the F-900 software webpage (http://felixinstruments.com/support/f-900-support).
Below this, a menu will appear on the display with the following options: Measure, Setup, View
and File. This is the F-900 Main Menu. After the instrument is powered on, the uptime and
battery life remaining will be displayed on the bottom line. The uptime, or time the instrument
has been powered on, is displayed in hours: minutes, followed by the battery life in percent.
Note: If the F-900 does not power on, eject the SD card or disconnect the mini-USB cable from
the front of the instrument. Then, power the F-900 on. Re-insert the SD card or reconnect the
charger.
Figure 8: The options on the Main Menu of the F-900.
Use the up and down arrows to switch between menu options and the right arrow to select.
Press the green power button to power off the F-900.
Note: To force a power off and reset of the F-900 at any point, press and hold the power
button for 10 seconds. This “emergency hard shut-down” feature exists to address hardware
or software problems and should not be used except when needed.

F-900 Instruction Manual 8/14/2017
1554 NE 3rd Ave, Camas, WA 98607, USA Phone: [phone]
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Charging the Internal Battery
The F-900 arrives with a wall charger that can be used to recharge the F-900 battery, as well as
for continually powering the unit during long-term monitoring. To charge the F-900:
Connect the mini-USB cable to the front panel of the F-900
Plug the charger into the wall
Check the charge status (on/off) at the “View>Battery” menu
Figure 9: The battery charger setup of the F-900.
The display will flash “powering off” on the top line when you hit the power key. For fastest
charging of the F-900, use the highest rated port on the charger and do not connect any
other USB devices to the charger.
To use the F-900 in Monitor Mode to continuously monitor fruit storage rooms or other locations,
or to run the instrument for days or weeks at a time, connect the mini-USB cable to the charger
cable and to the connection port on the front panel. Plug the charger into an electricity source.
WARNING: Do not store the F-900 without charged batteries! The internal batteries must
have charge to maintain the accuracy of the sensors, even when the unit is powered off.
Keep the instrument connected to the power supply for long term storage.

F-900 Instruction Manual 8/14/2017
1554 NE 3rd Ave, Camas, WA 98607, USA Phone: [phone]
www.felixinstruments.com
F-900 CO2PPM Sensor and Battery Power
The CO2PPM sensor will draw power when turned on, even if the F-900 is not actively
measuring. If trying to conserve battery life, the sensor should be turned off when not being
used.
Always turn the CO2PPM sensor to “off” for the fastest recharge, either using the mini-
USB cable and computer or with a wall charger.
The CO2PPM sensor ranges from 0-2000 ppm. The CO2PCT sensor is from 0-20% and
does not have the same power draw.
To turn off/on the CO2 PPM sensor:
1. Go to Setup>Sensor>Sensor Selection.
2. When asked “Are you sure you want to continue?” press Enter.
3. Press the down arrow to highlight CO2PPM.
4. Press the right arrow key to highlight On/Off.
5. Press the up/down arrow key to toggle On/Off the sensor.
6. Press Save when the desired setting is highlighted. This will turn off the CO2sensor until
you come back to this menu and turn it back on.
7. If you press Enter, the CO2sensor setting will only be temporarily saved. When the
instrument is turned off and then back on, the CO2sensor will be enabled.
Setup Sensor
C2H4 PPB On
C2H4 PPM On
CO2 PPM Off
CO2 PCT Off
O2 Off

F-900 Instruction Manual 8/14/2017
1554 NE 3rd Ave, Camas, WA 98607, USA Phone: [phone]
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Measure Menu: Taking a Measurement
To begin taking measurements, select the Measure menu option by pressing the right arrow
when Measure is highlighted on the main menu display. Make sure the IN and OUT ports on the
front panel of the instrument are clear from any obstructions. Create and open a file before
starting a measurement, otherwise the default filename on the SD card is File01.
If sampling ambient air, turn the unit on and leave the front ports free of obstruction. If sampling
a container or pallet, connect the Viton tubing to the IN port and place the end of the tubing into
the container or pallet to be sampled. If using the F-900RK, place the fruit to be sampled in the
fruit chamber, and connect it to the IN port on the unit. It is up to the specific setup whether the
OUT tubing is connected to the OUT port with Chamber Out filled with potassium permanganate
(KMnO4) and set to “on”. If left disconnected from the OUT port, the fruit chamber is allowed to
replenish with ambient air.
Sensor Stability
The F-900 will begin to warm-up. The F-900 will display the “Sensor Stability”screen after
pressing the RIGHT arrow to get into the Measure Menu. The display will show the file that is
open and the flow of gas being pumped through the instrument. Below this will be whether the
initialization is automatic or manual. If the initialization is automatic, the F-900 will precede
directly to the measurement (Graph Mode) once the sensors have stabilized. If the
initialization is manual, Monitor Mode will not be triggered until the user presses the right arrow
to enter Monitor Mode.
Press the down arrow key to switch between automatic and manual initialization.
Press the right arrow to skip the Sensor Stability screen and proceed to the Graph Mode
display.
If the offset auto-correction feature is enabled, then the unit will run the set zero process
automatically every 24 hours (or at the user defined time interval). The offset auto-correction
utilizes Chamber Out, which should be left full of KMnO4 even if Chamber Out is set to “off”
during normal measurements. For more details on the offset auto-correction, see page 35.
Note: The F-900 ethylene analyzer sensors should be given 24 hours to stabilize after being on
an airplane. Start a measurement and enable the Closed Loop (On). Then, allow the instrument
to measure for 24 hours while connected to a power supply.
Graph Mode
Graph Mode will be entered automatically once the unit has stabilized in Sensor Stability mode.
This view graphically displays the measured C2H4value over time. To switch Graph Mode into
Monitor Mode, press the right arrow. To exit the measurement, press Stop.

F-900 Instruction Manual 8/14/2017
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Figure 10: Graph Mode with red arrow indicating direction of movement.
Directly below the graph is the current ethylene value. Above the graph is the dynamic range
(on the left it is 1.000 ppm, on the right it is 2.000 ppm). The y-axis scale is set by the highest
value shown in the buffer. This range will scale vertically, dependent on the highest
concentration of ethylene measured. If the concentration is small, the dynamic range will reflect
this. For example, the initial value was 0.162 ppm and there is a sudden peak to 7.578 ppm. As
the spike or peak occurs, the graph will scale to 10.000 ppm. If the sample returns to 0.168
ppm, the scale will remain at 10.000 ppm until the graph and the buffer are cleared.
The scale of the graph can be increased or decreased by using the up and down arrows.
Pressing the up arrow will zoom in on the data, minimizing the visible range. Using the down
key will increase the scale, up to 200 ppm. Note that the minimum range of data visible (down to
0.150 ppm) depends on the current data being graphed. For example, if the current data is
3.486 ppm, the user may use the up key to zoom in to the 5 ppm range, but cannot zoom in to a
narrower 2 ppm range.
The graph begins on the left side and moves with the vertical line towards the right as more data
points are added. Once the time line reaches the right side of the display, the data will be
compressed to the far left.
The time scale relates directly to the vertical position line. In other words, the line moves to the
right as new data points are added. Every time a data point is added, the time scale is
incremented. For time under 10 minutes, the graph is updating almost every second. The
bottom of the display shows the uptime of the F-900 and current battery level.
Monitor Mode
The large bold value on the top line is the digitally filtered value of the raw ethylene
measurements. Next, the relative humidity in percent, of the gas stream in the instrument is
displayed followed by the temperature in degrees Celsius. The atmospheric pressure, is
displayed. Press the down arrow to view the flow rate in milliliters per minute. The default flow
rate is 80 mL per minute. If the unit has a high resolution CO2sensor on board, the CO2value in
ppm will be displayed below the ethylene value. If the unit has a low resolution CO2sensor, or
O2sensor on board, the value will be displayed in percentage (%).