134
03-914648-00:7
Calculate
Detector
Sensitivity
To calculate the sensitivity of the TCD, proceed as follows:
EXAMPLE 1: Known Sample Weight
S = PF
C
/W
Where:
S = Sensitivity in mV x mL/mg
P = Integrated peak area in mV x min
W = Weight of sample in carrier gas in mg
F
C
= Carrier gas flow in mL/min corrected to detector temp
F
C
= F
O
(T
D
/T
A
)(1-P
W
/P
A
)
Where:
F
O
= Flow rate measured at detector outlet (at ambient
temperature) in mL/min.
T
D
= Detector temperature in °K
T
A
= Ambient temperature in °K
P
W
= Partial pressure of H
2
O at ambient temperature in torr
P
A
= Ambient pressure in torr
Note:
The (1-P
W
/P
A
) expression applies only if using a bubble flowmeter.
EXAMPLE 2: Known Concentration of Sample in Detector
S = E/C
D
Where:
S = Sensitivity in mV x mL/mg
E = Detector signal (peak height) in mV
C
D
= Concentration of test substance in the measured peak
volume in mg/mL
Peak volume =
Peak width at half height (in min.) x gas flow rate at detector
(in mL/min) = W
•
h/2 x FC
Calculate
Detector
Detectivity
To calculate the detectivity of the TCD, proceed as follows:
Detectivity
2 x Noise
Sensitivity
=
Artisan Technology Group - Quality Instrumentation ... Guaranteed | (888) 88-SOURCE | www.artisantg.com
