Designating Gas Type - HP 5890 Series II Plus Reference Manual

Electronic Flow Sensing

Designating gas type

Designating gas type
To scale the displayed flow rate value properly, one of four commonly used
gases must be designated. The appropriate gas type is selected according
to Table 4•1:
Table 4-1. Defining Type of Gas to be Monitored
Number
1
2
3
4
To select one of these gases for a particular flow channel, press:
,
1
ENTER
chosen gas type.
If a gas other than one of the above standard four is used, select He,
N , H , or Ar/CH according to which one is closest in thermal
conductivity to the gas being used. Under no circumstances should any
corrosive gas be passed through the EFS.
The maximum usable range for H is 100 ml/minute. At higher flow rates
( >100 ml/min), where a gas other than He, N , or Ar/CH is being used,
or to ensure maximum accuracy in displayed flow rate, calibration of the
EFS may be necessary.
Gas Type
He (Helium)
N (Nitrogen)
2
H (Hydrogen)
2
Ar/CH (Methane in Argon)
4
( ) to display FLOW A (or FLOW B).
FLOW B
, , or is then pressed, followed by
2 3 4
, the current flow rate is displayed, scaled appropriately for the
Preferred Use
TCD
General
Capillary
ECD
. Upon pressing
ENTER
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