2020.07.24
•
REV. 2
• MASS FLOW METER OPERATING MANUAL
35
Using Gas Select and COMPOSER
To reconfigure your flow meter to flow a different gas, look up its Gas
Number (
). Then type:
Choose a gas:
[unit ID]
g
[Gas Number]
Example 1:
ag8
(reconfigures to flow nitrogen)
Example 2:
ag206
(reconfigures to flow P-10)
COMPOSER user mixes are selected in the same way. All COMPOSER gas
mixes are numbered between 236 and 255, starting at 255.
Choose a user mix:
[unit ID]
g
[Gas Number]
Example:
ag255
(reconfigures for user mix 255)
Defining a new COMPOSER gas mix is faster using serial commands than
using the front panel. The basic formula for this is:
[unit ID]
gm
[Mix Name]
[Mix Number]
[Gas1 %]
[Gas1 Number]
[Gas2 %]
[Gas2 Number]
…
•
[Mix Name]
Use a maximum of 6 letters (upper case and/or lower
case), numbers and symbols (space, period or hyphen only).
•
[Mix Number]
Choose a number from 236–255. If a user mix with
that number already exists, it will be overwritten. Use the number 0
to assign the next available number to your new gas.
COMPOSER
gas numbers are assigned in descending order from 255.
•
[Gas1 %] [Gas1 Number]
…
For each constituent gas, enter its molar
percentage (using up to 2 decimal places) and then its Gas Number
(
). You must have 2–5 gases in your COMPOSER mix.
After creating your COMPOSER mix, your flow meter will confirm the new
gas:
Example 1:
Create a mix of 71.35% helium, 19.25% nitrogen and 9.4%
carbon dioxide as Gas 252, called “MyGas1”.
a gm MyGas1 252 71.35 7 19.25 8 9.4 4
Response:
A 252 71.35% He 19.25% N2 9.40% CO2
Example 2:
Create a mix of 93% methane, 3% ethane, 1% propane, 2%
N₂ and 1% CO₂, using the next available gas number, called “MyGas2”.
a gm MyGas2 0 0 93 2 3 5 1 12 2 8 1
Response:
A 253 AIR 93.00% CH4 3.00% C2H6 1.00% C3H8 2.00% N2 1.00%
✓
Note:
The sum of all gas constituent
percentages must equal 100.00%.
