Notes For The Use Of The Shieldtorch System; Tuning The Shieldtorch (High Sensitivity Mode) - Agilent Technologies 7500 ICP-MS Operator's Manual

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Agilent 7500 ICP-MS ChemStation Operator's Manual
Tuning

Notes for the use of the ShieldTorch system

Plasma ignition
• Igniting the plasma is a little more difficult compared to that of the standard torch
because the Shield plate is between the torch and the coil.
• it is recommended to tune the instrument 30 minutes after igniting the plasma.
• When adjusting the EM, the Discriminator should be done under normal plasma
conditions.
When analyzing with the Normal Torch after analyzing with the ShieldTorch for a
long time, sometimes sensitivity becomes low. Cleaning of the ion lenses can rectify
this.

Tuning the ShieldTorch (High Sensitivity mode)

This mode gives the highest sensitivity at the normal plasma condition.
The Agilent 7500s model (discontinued model) is constructed prestigiously with two
rotary pumps. The two rotary pumps give the best performance with the highest
sensitivity. To achieve maximum performance of the two rotary pumps, make sure
the valve on the top of the second rotary pump is open. (Rotate it counterclockwise.)
When the cool plasma condition is activated, only one rotary pump is used. This
avoids generating cluster ions. To do this, close the valve on the top of the second
rotary pump. (Rotate it clockwise.) The sensitivity will be lower than when using two
rotary pumps, but the operating condition characteristics are the same. Also, the
adjustments are the same.
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