Table of Contents
Advertisement
Software features
measurement can be made without the occurrence of the secondary diffraction pat-
tern.
When the flake material is suspended in a volatile solvent, such as white spirit, vari-
flow is even more useful since it assists the rapid thermal stabilisation of the optics.
When the sample well is filled with fresh solvent, very high backgrounds can often
be observed. These arise from thermal gradients in the solvent causing steering of
the laser beam onto the inner rings of the internal detector. As the temperature
equilibrates, the background will fall to normal levels (80-100) and the measure-
ment can proceed. Pausing the pump after the solvent has had a chance to thor-
oughly disperse through the system will accelerate the fall of the background to
normal levels.
The ultrasonics radio buttons enable the ultrasonic transducer. The options are:
Either click and drag the slider bar to set the level, or type the exact level required in
the box to the right of the slider bar.
Determine the optimum ultrasound level and duration using manual control,
ensuring that the lowest setting giving satisfactory dispersion is obtained. Record
the settings and transfer these to the SOP in the Sampler Settings dialogue using
the slider controls.
Hydro 2000µP
Ultrasonics
Warning!
When using solvents, especially those with low ignition points, minimise
the use of ultrasonics. There is a remote possibility that localised heating
caused by the ultrasonic action may cause an explosive reaction. Check the
Material Safety Data Sheets for all substances used.
None – no ultrasound.
Continuous (from sample addition) – ultrasound is activated after sample
is added and will run continuously.
Pre-measurement – ultrasound is activated for a set time prior to measure-
ment. For pre-measurement mode, type in the required duration in seconds in
the Duration box.
Continuous (from start) – ultrasound is active throughout the measure-
ment. Ultrasound will start after the electrical background is complete. The
stabilising period will add a delay between the electrical background and the
optical alignment. During this delay ultrasound will be active to allow bubbles
to be driven from the dispersant.
Chapter 3
Page 3-7
Advertisement
Table of Contents
