Agilent Technologies 7500 ICP-MS Operator's Manual page 105

Agilent 7500 ICP-MS ChemStation Operator's Manual
Tuning
Typical values for the ShieldTorch (High Sensitivity mode
Tuning parameters
RF Power (W)
Smpl Depth (mm)
Carrier Gas (L/min)
Makeup Gas (L/min)
PeriPump (rps)
Extract 1 (V)
Extract 2 (V)
Einzel 1,3 (V)
Einzel 2 (V)
Omega Bias (V)
Omega (+) (V)
Omega (-) (V)
QP Focus (V)
Plate Bias (V)
QP Bias (V)
5 Adjust Torch-H and Torch-V position.
6 Adjust the RF Power.
7 Adjust the Smpl Depth (Sampling depth).
Typical Range
∼
1500
1200 1600
∼
6
4 8
∼
1.2
0.8 1.3
∼
0
0 0.4
∼
0.2
0.06 0.20
∼
-180
-200 -100
∼
-35
-150 -10
∼
-100
-130 -40
∼
10
0 15
∼
-30
-100 -25
∼
8
0 30
∼
5
-30 0
∼
0
0 10
∼
-10
-10 -5
∼
-5
-10 -5
Set lower than the normal value.
Set as to make the total flow rate, including the carrier gas, to
be about 1.2 L/min.
Set higher to get a high sensitivity, but making it too high
doesn't always increase further sensitivity.
Even if the value of the Einzel lens is decreased, the
background may hardly be increased and only the sensitivity
may be increased.
If this value is lowered, sensitivity may be increased.
Even if the value of the Omega lens is decreased, the
background may hardly be increased and only the sensitivity
may be increased.
Because the ion energy is low, it is necessary to make this
value smaller than that of the Standard torch. Be sure to use
with 0 or (+). In the case of (-), the background will sharply
rise.
Because the ion energy is low, it is necessary to add negative
voltage.
Because the ion energy is low, it is necessary to add negative
voltage.
)
Note
4-29