Instrument Validation

Assessment of instrument performance is readily carried out using the validation software module built into all Aquarius instruments and released by E-SEF, 'encoded software enhancement facility'.

Laboratories subject to regulatory control, or following G.L.P. are provided with a range of Pharmacopoeia (EP) tests as well as tests using filters traceable to national standards with certificates of calibration issued by Cecil Instruments. A selection of the tests are shown here.

Absorbance Accuracy The Pharmacopoeia (EP) test for absorbance accuracy, using a 60mg/L solution of Potassium Dichromate in a 10mm pathlength cuvette, is shown here.
Optical Bandwidth The optical bandwidth of the instrument may be validated by measuring the half height width of the narrow deuterium emission line at 656.1nm. The measurement is carried out automatically.
Straylight Straylight is measured following the Pharmacopoeia (EP) test, using a 1.2% w/v solution of Potassium Chloride in water measured against water in the reference beam.

Validation Using Filters

Absorbance accuracy is most conveniently measured using certified filter sets calibrated by Cecil Instruments against NPL certified standards. A validation printout for the procedure is shown here. Wavelength calibration is also carried out using certified filters.

Cell and Wavelength Programming

All Aquarius instruments are fully programmable. Cell programmes may use four, six or eight cell changers, with a single autozero or individual zeros for each cell.

Wavelength programmes are provided for up to ten different wavelengths and cell and wavelength programmes may be combined.

Sampling/Temperature Control

A complete range of sampling accessories is available. A selection of auto-sample changers, some with water temperature control, is shown on the left. A thermoelectric controller with a single cell holder and four cell changer is shown above. Control is through the instrument microprocessor system with screen display of temperature.