Photometric system

The sample preparation – the digestion

Sample preparation is an important component of the complete analyses. Only a perfectly harmonised system enables complex samples, e.g. soils, substrates, etc. to be analysed. The system LASA AGRO has perfectly been tailored to meet these demands.
The standardised sample preparation guarantees precise and reproducible analyses results. The prepared extraction concentrate can be used as digestion solution for all macro- and microelements.

Other extraction methods can certainly also be carried out and the user has the option to adapt the system which he is familiar with.
The extraction case contains the complete equipment for soil digestions, e.g. solar balance, funnels, folded filter papers, and 1 ltr. extraction concentrate.

The measuring unit – the photometer LASA AGRO 1900

This is the heart of this system is the photometer LASA AGRO.
For mobile use we recommend the compact LASA AGRO 1900 with more than 200 pre-programmed cuvette tests for water, peat moss, substrate and soil analysis.
The portable photometer unites highest accuracy with practicality for everyday use.

The rugged waterproof housing is made in a shock tested design. The instrument has a large easy-to-ready screen and a simple user interface that makes testing easier than ever, even in the harshest conditions. Select the desired parameter by pressing a button from a list, insert the prepared vial and start the measurement – done.

The measuring unit – the photometer LASA AGRO 3900

The LASA AGRO 3900 is the ideal soil and water benchtop spectrophotometer for professional use in laboratories.
The new 2D barcode also details the batch number and the expiry date of the reagents.

During the proven ten times rotating measurement process using the barcode reader, the LASA AGRO 3900 immediately picks up all the information on the cuvette.
The batch number and expiry date are documented along with the measurement result.

User-defined methods with linear and nonlinear calibration curves can be programmed itself via the acquisition of spectra (320-1100 nm), concentration, absorbance and turbidity measurement. The variable cuvette sizes from 10 to 50 mm allow wide measuring ranges.

Evaluation of measurement results

All cuvettes are labelled with a barcode which provides all necessary information for the photometer. When inserting the cuvette in the photometer, the integrated barcode reader recognises the cuvette and the required wavelength and factors are adjusted automatically. The rotation of the cuvette during the measuring process makes operating errors and incorrect measurements virtually impossible. The evaluation of the measuring results can be carried out in

• mg / 100 g soil for soil analyses
• mg / liter substrate for substrate, peat analyses
• mg / liter solution for nutritive solutions, drainage water, etc.

The interpretation of the analysis results are carried out according to users requirements. Tables for different plants are provided particularly for the corresponding application.

An important component of the LASA AGRO system is the interpretation of the measured values. The evaluation using tables is a simple way based on the long-term experience of the official German Agricultural Investigation and Research Institutions (VDLUFA). For both horticultural and agricultural outdoor crops, the tabular guide values are given in mg / 100 g soil nutrient, either as pure nutrient (e.g. with N, Mg) or in the oxide form, e.g. K2O or P2O5. A conversion is no longer necessary.

The tables help to determine the soil class and provide information on the required fertilizer quantity. For substrate analyses, crops are divided into three groups with the respective nutrient target values and a calculation example in case of nutrient deficiency.
All tables are included in the accompanying manual of the LASA AGRO system.

Further information on request.