VICI 120 Dynacalibrator - Manual (Page 7)

Calculating the Concentration
A calibrated Dynacalibrator flow rate table is included in the certification
documents shipped with the instrument. Use this flow rate and your
device’s permeation rate to calculate output concentration.
Concentration of the permeant compound in the span outlet stream is
inversely proportional to the carrier flow rate through the chamber. It is
determined using the folowing equation:
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Where: K = 24.45 / molecular weight of gas
P = permeation rate in ng/min (information included with
the permeation device documentation)
F = Chamber carrier flow (ml/min)
If the permeation rate is known for some reference temperature, the rate at
a second temperature can be estimated as follows:
log P = log P
O
+ 0.034 (T - T
O
)
Where: P
O
= Permeation rate at reference temperature T
O
P = New permeation rate at temperature T
Certified devices should be used only at the temperature
specified on the certificate.
Using any permeation device beyond its recommended
temperature range could result in the destruction of the
device by explosion and/or changes in the membrane
characteristics. If in doubt, contact VICI Metronics with
the part number of the device to determine its maximum
temperature limit.
Flow Correction Factor
When using the portable calibrator in an environment other than standard
conditions, the flow must be corrected to standard temperature and pres-
sure using the following formula:
Flow = (0.6262) F
C
* (P / T)
Where: Flow = indicated flow corrected to standard temperature
and pressure. This corrects the flow to standard
conditions when the flowmeter is at a different
temperature and pressure.
P = ambient pressure in mm Hg
T = Flowmeter temperature in °Kelvin (273+C)
F
C
= Calibrated flow when the flowmeter is at standard
conditions.
A calibrated Dynacalibrator flow rate table is included in the back
of this manual.
OH YEAH!!?? Use this flow rate and your device’s
permeation rate to calculate output concentration