Alignment of the Sample Probe on the Agilent PSD 120

Created by Tina Harville over 2 years ago | Last modified by Carlos Vargas over 1 year ago

This Information Applies To: Agilent GTA 120, Agilent 240Z AA Spectrometer, Agilent 280Z AA Spectrometer, Agilent 240FS/GTA120/PSD120/UltrAA System

Issue:

It is important to align the sample probe of the Programmable Sampler Dispenser (PSD) 120, so that the sample is injected properly into the graphite tube.

The correct alignment of the probe (the end of the capillary protruding from the base of the probe holder) is:

The probe locates in the center of the vial when it collects the solution.
The probe depth is sufficient to remain under the liquid during the drawing up phase.
It enters and exits the rinse solution vessel without touching the sides or base.
Enters and exits the graphite tube without touching the sides of the injection hole.

Steps to follow:

Make sure that the GTA workhead is properly aligned with the optical path and that your PSD is properly installed.
Place an empty vial on the dispenser carousel in position 1.
Create a method worksheet. See the online Help.
Go to the Analysis page. Select Instrument menu > Furnace Facilities. Turn on the camera (if installed).
Click Align. The autosampler will position the capillary in position 1 in a completely down position. (See Figure 1)

Figure 1. Graphite Furnace AA Sample Probe Alignment
Verify that the probe is correctly aligned to the sample vial. The probe should almost reach the bottom of the vial, but not actually touch it (See Figure 2).

Figure 2. Probe alignment in vial
If the end of the probe is too far from the bottom of the vial, or if it touches the bottom of the vial:
a. Loosen the probe guide screw and adjust the length of the capillary as necessary.
b. If necessary, loosen the screw on the probe holder and adjust the angle of the probe until it is aligned vertically in the vial.
Once the correct length of the probe in the vial has been established, click OK in the confirmation window. The probe will move to the furnace head.
Place a finger under the probe arm as the capillary begins to descend to the oven and gently lower the hand arm.
Check the capillary travels through the entry hole of the furnace tube and does not touch the sides. If necessary, release the locking screw located below the PSD, adjust the position, then relock the screws.
Lower the probe into the graphite furnace. Use the furnace camera window or the viewing mirror to check the location of the tip inside the tube (See Figure 3). If necessary, use the depth adjustment screw to adjust the tip so it is about 1 mm above the base of the graphite tube. Tighten the locking screws.

Figure 3. Lowering the Capillary into the Graphite Furnace