F-900 Instruction Manual 8/14/2017
1554 NE 3
rd
Ave, Camas, WA 98607, USA Phone: (360) 833-8835
6
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 4-5
O
C 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.
Summary of Contents for F-900
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