SOP concept of automatic control

Mastersizer 2000 software provides a user friendly framework to provide precise control of the core instrumental functions of the particle size analyzer and it's sample dispersion units.

With the introduction of the Mastersizer 2000, Malvern Instruments formalized the concept of the use of built-in macros, known as SOPs (Standard Operating Procedures) to control and standardize the complete measurement including the production of standardized reports.

These SOPs are created in a matter of minutes by the operation of a wizard which guides users through the choices which determine the success of their measurements. Every aspect of the measurement can be set up; from the duration of the measurement through labeling protocols to the setting of the sample dispersion units. Wherever users are faced with a choice of setting an advice button is available to guide users to the right selection of parameters for their samples.

Parameters controlled:

Sampler selection
The choice of the most appropriate sample dispersion unit.

Material
The selection of the optical properties of the material from a Refractive Index Database stored in the software.

Calculation
The selection of transformations to number, surface or length, if appropriate.

Result emulation
The user is able to specify an appropriate result emulation factor file which will apply predetermined offsets to the Mastersizer 2000 result to emulate the results expected from another instrument or sizing technique.
(Result emulation factor files are created by a stand alone utility in the tools menu of the software, which compares results obtained using alternative techniques with those obtained using the Mastersizer 2000 and calculates the offsets needed to produce an emulation.
As an example, a user may have previously used sieve measurements to control a process and now may want to replace the sieves with the Mastersizer. The Mastersizer results may well differ from the sieve results owing to the particles being non- spherical but the user may want the opportunity to produce sieve-like measurement for comparison purposes. Result emulation satisfies this requirement.)

Model
Different models are available to optimize results in several clearly recognizable measurement situations. Most measurements are performed using a general purpose model, but models are also available for single narrow modes and multiple narrow modes. Users are guided in their selection of the appropriate model by pictograms illustrating the type of particle size distributions which are optimized by the models.

Labels

The choice of labeling protocol appropriate to the laboratory using the system. Options available include, automatic ability to create "locked" labels, naming the sample sources and bulk lots in order so that operators don't have to type these in each time. There is also an auto increment feature which increments the sample reference number by one with each successive measurement. This is both a time saver and a guarantee that no results have been disposed of or hidden as such actions will result in a break in the number series.

Operator instructions

Instructions to operators can be displayed at two stages during the measurement - before the measurement to advise on sampling or sample dispersion and after the measurement to advise on actions to be taken to dispose of the sample or other housekeeping issues.

Report selection

There is a choice of several standard Malvern-designed reports. Custom reports can be created using the stand-alone Report Designer utility in the Tools menu of the software.

Export

Export templates can be created to allow the user to specify the measurement parameters that they wish to export to other software packages.

Sampler settings

Wet dispersion units: Pump speeds, stir speeds, ultrasonication intensities and duration, automatic or manual tank filling.
Scirocco dry powder feeder: Sample feed rate and dispersive air pressure.

Measurement

Background and sample measurement times, enabling of obscuration filtering and autodilution. Setting up cleanliness and diameter alarms. Specifying Quality Control calculations to be applied to results.

Measurement cycles

The number of repeat measurements to be performed. These are specified as "aliquots" (each aliquot is a fresh sample) and measurements per aliquot.

Quantities

This dialogue allows user companies to standardize on the specification of quantities applied to samples, predispersants or surfactants (drops, microliters, milligrams or grams). This helps assure the uniformity of measurements.