Basic HTML Version
CCD - SRI Instruments
CCD - Catalytic Combustion Detector
45
|
|
|
●
Hydrocarbon and hydrogen selective
●
Detects down to 500ppm
●
Gasless operating capability
●
Inexpensive
●
Built-in spare element
About as sensitive as a
the Catalytic Combustion Detector has the hydrocarbon selectivity of an
, plus the ability
to operate on air alone. Because the CCD requires no compressed gases like hydrogen or helium, it can be used in
SRI's
where our
supplies the ambient air carrier gas. The CCD
detector can also be used as a hydrocarbon monitor in non-chromatographic applications where the CCD senses the
total hydrocarbon content of a flowing air stream, or as a
The CCD sensor, shown above, is rugged and can be expected to last a long time. A second sensor is included in
the detector housing at no extra cost, providing a built-in replacement should the first sensor become
inoperable. Replacement sensor sets install in minutes without tools and are very economical, making this detector a
good choice for academic settings where the sensors may be damaged by inexperienced operators.
Our CCD detector consists of a tiny coil of platinum wire embedded in a catalytic ceramic bead. A small electric current
flows through the patinum coil, heating the ceramic bead to around 500
o
C. The CCD is maintained in an
oxidative environment by using air carrier gas. When a hydrogen or hydrocarbon molecule impacts the hot bead, it
combusts on the surface and raises the temperature and resistance of the platinum wire. This resistance change causes
the detector output signal to change, thus producing a peak. The brass detector housing is mounted on a stainless
steel bulkhead fitting, which is mounted directly in the wall of the GC column oven.
This chromatogram shows a separation
of 1000ppm methanol from acetone at
150
o
C and air carrier from the Gas-less
GC's
The
negative peak at the beginning of the
run is water.