Thermo Scientific FOCUS GC, Instruction Manual

Page: 78 / 356

Chapter 3
Gas Control
Measuring Gas Flow
78 Instruction Manual
Measuring Gas Flow
The septum purge and split flows can be measured at the relevant vents located on
the top of the instrument. Detector gas flows can be measured at the detector vent.
Use a bubble flow meter or a calibrated electronic flow meter to check flows. A
built-in flow calculator, accessible by the GC keypad, helps you measure the flow
when you use a bubble flow meter.
OPERATING SEQUENCE
Measuring the Detector Gas Flows with a Bubble Meter
Materials required:
• Graduated bubble flowmeter (the bulb must be half-filled with a soap
solution)
• Detector base body adapter (for FID only)
WARNING! Do not measure hydrogen together with air or oxygen. This can create an explosive
mixture. Always measure the gases separately.
1. Attach the inlet line of the flowmeter to the exit of the detector base body
using the adapter.
2. While holding the bubble flowmeter vertically, squeeze and release the bulb
to produce a meniscus in the bubble meter.
3. In Main Menu, move the cursor until
Others
is selected, then press
ENTER
.
4. Scroll to
Time
then press
ENTER
.
5. Scroll to
Measured vol.
and set the volume that you wish to measure.
TIME
V=100 F=100.0 01:00
Flowmeter volume 100